![\"\"](\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2023\/02\/Prochazka-tab-1-N.jpg\")
<\/a>\nThe\u00a0geometry of\u00a0the\u00a0model was set according to\u00a0the\u00a0available drawings of\u00a0the\u00a0most used facilities at\u00a0the\u00a0WWTP. A\u00a010 m long section of\u00a0the\u00a0aeration tank was simulated together with the\u00a0flow distribution structure in\u00a0order to\u00a0achieve a\u00a0fully developed flow field at\u00a0the\u00a0beginning of\u00a0the\u00a0flow distribution structure [1].<\/p>\n
![\"\"](\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\")
<\/a>Fig.\u00a01. CFD model \u2013 cross section \u2013 simulated part marked in\u00a0red<\/h6>\n<\/a>Fig.\u00a02. CFD model \u2013 floor plan \u2013 simulated part marked in\u00a0red<\/h6>\nMETHODOLOGY<\/h2>\n
Before any simulation, it is\u00a0important to\u00a0have a\u00a0general understanding of\u00a0how the\u00a0structure works and to\u00a0establish the\u00a0most important phenomena taking place there. Flow distribution facilities are usually based on\u00a0outlet openings. The\u00a0overflow velocity of\u00a0the\u00a0outlet opening is\u00a0determined by the\u00a0hydraulic elevation in\u00a0front of\u00a0it. Therefore, if\u00a0openings of\u00a0the\u00a0same length have the\u00a0same overflow height, the\u00a0flow rate must be the\u00a0same. However, even a\u00a0small change in\u00a0water level causes large differences between the\u00a0flows.<\/p>\n
And that is\u00a0the\u00a0problem with this facility. The\u00a0channel, which distributes the\u00a0flow to\u00a0the\u00a0four outlet openings, is\u00a0quite long and a\u00a0backflow is\u00a0formed along it. The\u00a0water level in\u00a0the\u00a0facility will therefore not be constant. The\u00a0openings in\u00a0the\u00a0bed that drain the\u00a0water into the\u00a0reservoirs are relatively large and therefore do not contribute to\u00a0an even distribution of\u00a0the\u00a0flow.<\/p>\n
Water levels at the facility<\/h3>\n
Four different simulations of\u00a0the\u00a0distribution facility with different flow rates were performed. The\u00a0results show that the\u00a0above considerations are correct. At\u00a0the\u00a0beginning of\u00a0the\u00a0channel, the\u00a0water level drops. As\u00a0the\u00a0water flows from the\u00a0aeration tank into the\u00a0narrow channel of\u00a0the\u00a0distribution facility, the\u00a0velocity gradient increases and therefore the\u00a0water level must drop. Further along the\u00a0channel, part of\u00a0the\u00a0water flows through side openings into the\u00a0reservoirs, the\u00a0flow rate decreases and the\u00a0water level increases [2].<\/p>\n
The\u00a0model shows this at\u00a0all flow rates. At\u00a0low flow rates (377 and 566 l\/s) the\u00a0difference is\u00a0so small that this effect is\u00a0only theoretical and in\u00a0reality the\u00a0more significant difference in\u00a0water level is\u00a0caused by other factors (waves, wind). However, at\u00a0high flow rates (3,000, 6,000 l\/s), this effect is\u00a0quite significant. This is\u00a0shown in\u00a0the\u00a0following figures (Fig.\u00a03\u20137). The\u00a0colour scale shows the\u00a0difference between the\u00a0constant level approximation and the\u00a0simulated water level in\u00a0metres.<\/p>\n
All described effects can be seen even better in\u00a0Fig.\u00a07. The\u00a0height of\u00a0the\u00a0water level is\u00a0shown in\u00a0metres.<\/p>\n
<\/a>Fig.\u00a03. Simulated water level difference Q = 377 l\/s<\/h6>\n<\/a>Fig.\u00a04. Simulated water level difference Q = 566 l\/s<\/h6>\n<\/a>Fig.\u00a05. Simulated water level difference Q = 3,000 l\/s<\/h6>\n<\/a>Fig.\u00a06. Simulated water level difference Q = 6,000 l\/s<\/h6>\n<\/a>Fig.\u00a07. Simulated water level in\u00a0the\u00a0flow distribution object<\/h6>\nRESULTS<\/h2>\n
Fig.\u00a08\u201311 show the\u00a0contours of\u00a0the\u00a0simulated flow velocities in\u00a0the\u00a0channel cross-sections and in\u00a0the\u00a0openings, which can give some idea of\u00a0the\u00a0general flow pattern.<\/p>\n
At the\u00a0beginning of\u00a0the\u00a0channel, the\u00a0flow narrows quite significantly. It\u00a0means that the\u00a0first half of\u00a0the\u00a0first opening is\u00a0not fully utilized hydraulically. This is\u00a0again more important under high flow conditions. This effect could actually be less significant than in\u00a0the\u00a0model because there is\u00a0high turbulence in\u00a0the\u00a0aeration tank, which is\u00a0difficult to\u00a0assess in\u00a0the\u00a0model.<\/p>\n
The\u00a0colours represent the\u00a0overall velocity. Therefore, the\u00a0velocity in\u00a0the\u00a0last opening is\u00a0the\u00a0lowest. The\u00a0\u201cy\u201d component of\u00a0the\u00a0velocity is\u00a0quite significant in\u00a0the\u00a0first three openings [3].<\/p>\n
<\/a>Fig.\u00a08. Flow velocity contours Q = 377 l\/s<\/h6>\n<\/a>Fig.\u00a09. Flow velocity contours Q = 566 l\/s<\/h6>\nFig.\u00a010. Flow velocity contours Q = 3,000 l\/s<\/h6>\n<\/a>Fig.\u00a011. Flow velocity contours Q = 6,000 l\/s<\/h6>\nFlow distribution<\/h3>\n
Tab. 2 and Fig.\u00a012 show the\u00a0flow distribution under different flow conditions. Since no measured data were available, the\u00a0model could not be calibrated. The\u00a0sensitivity of\u00a0the\u00a0flows to\u00a0the\u00a0overflow height was adjusted only according to\u00a0the\u00a0theoretical flow curve. Preliminary results showed a\u00a0similar distribution of\u00a0flow under all flow conditions; however, at\u00a0low flows the\u00a0overflows were found to\u00a0be too sensitive to\u00a0overflow height. The\u00a0final results after appropriate adjustment of\u00a0this sensitivity are shown in\u00a0Tab. 2.<\/p>\n
Tab. 2. Flow distribution<\/a><\/h5>\n<\/a>Fig.\u00a012. Flow distribution<\/h6>\nThe\u00a0results show that the\u00a0flow distribution is\u00a0fairly evenly distributed at\u00a0low values; however, with increasing flow, the\u00a0unevenness of\u00a0the\u00a0distribution increases, which is\u00a0caused by the\u00a0differences in\u00a0the\u00a0water level described above [4].<\/p>\n
DISCUSSION<\/h2>\n
Since the\u00a0results showed that the\u00a0flow distribution is\u00a0not dependent on\u00a0the\u00a0flow itself, it was proposed to\u00a0solve the\u00a0problem by adjusting the\u00a0lengths of\u00a0the\u00a0overflows.<\/p>\n
The\u00a0introduction of\u00a0baffles across the\u00a0channel does not seem like a\u00a0good idea either. The\u00a0channel itself is\u00a0quite narrow and introducing any major obstructions into it would reduce its hydraulic capacity and rather make the\u00a0problem worse.<\/p>\n
The\u00a0best solution is\u00a0probably adjusting the\u00a0size of\u00a0the\u00a0openings at\u00a0the\u00a0channel bed to\u00a0distribute the\u00a0flow. Smaller openings at\u00a0the\u00a0end of\u00a0the\u00a0channel will cause a\u00a0hydraulic loss that will compensate for the\u00a0higher water level at\u00a0high flow rates. At\u00a0low flow rates, the\u00a0hydraulic loss will be small and the\u00a0flow distribution will not be affected.<\/p>\n
Setting the\u00a0size of\u00a0the\u00a0lower openings<\/h3>\n
Several simulations were performed to\u00a0find the\u00a0best possible combination of\u00a0opening sizes. The\u00a0optimization was based on\u00a0the\u00a0maximum flow rate (6,000\u00a0l\/s) and a\u00a0flow rate of\u00a0566 l\/s was used to\u00a0confirm the\u00a0good performance of\u00a0the\u00a0design at\u00a0low flow rate.<\/p>\n
The\u00a0simulations were performed iteratively. First, the\u00a0size of\u00a0the\u00a0openings was reduced to\u00a0half the\u00a0original size. The\u00a0original openings were very large (velocity 0.136 m\/s at\u00a0maximum flow rate), and although their size was halved, they did not cause much energy loss. The\u00a0flow through the\u00a0modified structure was simulated and the\u00a0flow rates into the\u00a0individual reservoirs were obtained.<\/p>\n
Optimization process<\/h3>\n
Tab. 3 and Fig.\u00a013 show the\u00a0simulation results of\u00a0the\u00a0above versions and show the\u00a0iteration process.<\/p>\n
Tab. 3. Comparison of\u00a0the\u00a0different phases of\u00a0the\u00a0iterative process (Qmax<\/sub>)<\/a><\/h5>\n<\/a>Fig.\u00a013. Example of\u00a0iterative process<\/h6>\nProposed improvement<\/h3>\n
The\u00a0proposed improvement is\u00a0shown in\u00a0Fig.\u00a014. The\u00a0red hatched areas show the\u00a0placement of\u00a0the\u00a0plates that close the\u00a0parts of\u00a0the\u00a0openings. In\u00a0the\u00a0simulations, these baffles were placed on\u00a0the\u00a0side of\u00a0the\u00a0channel and were aligned with the\u00a0channel wall.<\/p>\n
<\/a>Fig.\u00a014. Final dimensions of\u00a0the\u00a0proposed openings<\/h6>\n<\/a>Fig.\u00a015. Velocity contours of\u00a0the\u00a0flow pattern Q = 6,000 l\/s<\/h6>\nFunction principle<\/h3>\n
The\u00a0following figure (Fig.\u00a016) shows the\u00a0function of\u00a0the\u00a0baffles in\u00a0the\u00a0lower openings. Although the\u00a0water level rises along the\u00a0channel, the\u00a0water levels in\u00a0the\u00a0still chambers are almost equal. The\u00a0difference between the\u00a0water levels in\u00a0the\u00a0channel and in\u00a0the\u00a0still chamber is\u00a0due to\u00a0hydraulic losses caused by\u00a0the\u00a0baffles. The\u00a0colours in\u00a0the\u00a0figure show the\u00a0difference between the\u00a0approximate constant water level and the\u00a0calculated level.<\/p>\n
<\/a>Fig.\u00a016. The\u00a0water level in\u00a0the\u00a0distribution object<\/h6>\nCONCLUSION<\/h2>\n
The\u00a0following table and diagram (Tab. 4, Fig.\u00a017) show a\u00a0comparison of\u00a0the\u00a0simulation results for the\u00a0current state and the\u00a0final proposed improvement. For\u00a0improvement, only the\u00a0maximum flow (Qmax) and the\u00a0mean daily flow (Q24) have been simulated so far. It can be seen from the\u00a0results table that the\u00a0proposed state of\u00a0the\u00a0distribution facility meets the\u00a0conditions for an even distribution of\u00a0flows, and the\u00a0objectives of\u00a0the\u00a0research have thus been fulfilled. Considering the\u00a0fact that the\u00a0selected distribution facility is\u00a0commonly used in\u00a0the\u00a0field, the\u00a0results of\u00a0the\u00a0research can be easily applied in\u00a0practice, namely to\u00a0a larger number of\u00a0WWTP.<\/p>\n
Tab. 4. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/a><\/h5>\n<\/a>Fig.\u00a017. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/h6>\nOther possible improvements<\/h3>\n
This improvement shows that it is\u00a0possible to\u00a0reduce the\u00a0problem of\u00a0uneven flow distribution by introducing baffles into the\u00a0openings, the\u00a0installation of\u00a0which is\u00a0quick, simple, and without the\u00a0need for building modifications. Further attention in\u00a0possible follow-up research should be paid to\u00a0the\u00a0shape of\u00a0the\u00a0baffles.
\nIt cannot be ruled out that some sediments could accumulate in\u00a0the\u00a0quiet zones behind these baffles and especially in\u00a0the\u00a0corners (Fig.\u00a018), which could cause a\u00a0problem with sediment clogging the\u00a0inlet branches into the\u00a0reservoirs in\u00a0the\u00a0future. Clogging with sediment will most probably affect the\u00a0hydraulics of\u00a0the\u00a0distribution facility so that the\u00a0uneven flow distribution will occur again.<\/p>\n
<\/a>Fig.\u00a018. Sediment is\u00a0likely to\u00a0accumulate in\u00a0dead zones in\u00a0the\u00a0corners<\/h6>\nAcknowledgements<\/h3>\n
This article was supported by grant 3600.54.10\/2021 \u201c3D modelling of\u00a0selected
\nvariants of\u00a0flow distribution in\u00a0inlet galleries\u201d.<\/p>\n
<\/p>\n
The Czech version of this article was peer-reviewed, the English version was translated from\u00a0the Czech original by Environmental Translation Ltd.<\/p>\n","protected":false},"excerpt":{"rendered":"
The\u00a0main objective of\u00a0the\u00a0article was to\u00a0optimize the\u00a0facilities used to\u00a0distribute flows in\u00a0inlet galleries, which are used not only in\u00a0water treatment plants, but also in\u00a0wastewater treatment plants (WWTP). While working in\u00a0the\u00a0field of\u00a0WWTP, it\u00a0was found that there are no optimized facilities in\u00a0the\u00a0Czech Republic or globally for uniform distribution of\u00a0flows to\u00a0any number of\u00a0inlet branches into reservoirs of\u00a0the\u00a0same flow rate.\u00a0 Currently, in\u00a0most unregulated facilities, there are significant differences between the\u00a0various inlet branches to\u00a0the\u00a0reservoirs. In\u00a0regulated facilities, the\u00a0outlets must be regulated at\u00a0each change in\u00a0flow rate and, for changes in\u00a0the\u00a0number of\u00a0inlets to\u00a0the\u00a0reservoir (e.g., due to\u00a0reservoir shutdown), each outlet must be manually adjusted (e.g., using a\u00a0sluice gate) so that all inlets to\u00a0reservoirs have the\u00a0same flow rate. In\u00a0more modern cases, the\u00a0sluice is\u00a0equipped with an electric motor for changing the\u00a0position and a\u00a0probe sensing the\u00a0level. The\u00a0central unit then calculates the\u00a0flow rate in\u00a0the\u00a0individual reservoir inlets and adjusts the\u00a0position of\u00a0the\u00a0sluice gates so that the\u00a0same flow rate is\u00a0achieved everywhere. The\u00a0objective of\u00a0the\u00a0research was to\u00a0optimize the\u00a0distribution facility so that the\u00a0inlets to\u00a0the\u00a0reservoirs reach similar values for the\u00a0flow rate when both the\u00a0inflow to\u00a0the\u00a0distribution facility and the\u00a0number of\u00a0inlet branches to\u00a0the\u00a0reservoirs are changed, without significant regulation at\u00a0the\u00a0distribution facility. In\u00a0order to\u00a0make the\u00a0research easily applicable to\u00a0as many distribution facility as\u00a0possible, the\u00a0most commonly used flow distribution facilities (fountain spillway, flume with outlets fitted with a\u00a0sluice gate and probe for level monitoring, etc.) were selected to\u00a0address the\u00a0issue. Different flow conditions were simulated on\u00a0the\u00a0selected facilities (in different variants and shapes); after their analysis the\u00a0facilities were optimized in\u00a0order to\u00a0achieve the\u00a0most similar flows at\u00a0the\u00a0inlets to\u00a0the\u00a0individual reservoirs.<\/p>\n","protected":false},"author":8,"featured_media":18094,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[86],"tags":[3043,3044,3066,3067],"coauthors":[2448],"class_list":["post-21185","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydraulics-hydrology-and-hydrogeology","tag-cfd","tag-flow-3d","tag-flow-distribution","tag-inlet-galleries"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/comments?post=21185"}],"version-history":[{"count":6,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions"}],"predecessor-version":[{"id":32041,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions\/32041"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/18094"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=21185"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=21185"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=21185"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=21185"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
<\/a>Fig.\u00a02. CFD model \u2013 floor plan \u2013 simulated part marked in\u00a0red<\/h6>\nMETHODOLOGY<\/h2>\n
Before any simulation, it is\u00a0important to\u00a0have a\u00a0general understanding of\u00a0how the\u00a0structure works and to\u00a0establish the\u00a0most important phenomena taking place there. Flow distribution facilities are usually based on\u00a0outlet openings. The\u00a0overflow velocity of\u00a0the\u00a0outlet opening is\u00a0determined by the\u00a0hydraulic elevation in\u00a0front of\u00a0it. Therefore, if\u00a0openings of\u00a0the\u00a0same length have the\u00a0same overflow height, the\u00a0flow rate must be the\u00a0same. However, even a\u00a0small change in\u00a0water level causes large differences between the\u00a0flows.<\/p>\n
And that is\u00a0the\u00a0problem with this facility. The\u00a0channel, which distributes the\u00a0flow to\u00a0the\u00a0four outlet openings, is\u00a0quite long and a\u00a0backflow is\u00a0formed along it. The\u00a0water level in\u00a0the\u00a0facility will therefore not be constant. The\u00a0openings in\u00a0the\u00a0bed that drain the\u00a0water into the\u00a0reservoirs are relatively large and therefore do not contribute to\u00a0an even distribution of\u00a0the\u00a0flow.<\/p>\n
Water levels at the facility<\/h3>\n
Four different simulations of\u00a0the\u00a0distribution facility with different flow rates were performed. The\u00a0results show that the\u00a0above considerations are correct. At\u00a0the\u00a0beginning of\u00a0the\u00a0channel, the\u00a0water level drops. As\u00a0the\u00a0water flows from the\u00a0aeration tank into the\u00a0narrow channel of\u00a0the\u00a0distribution facility, the\u00a0velocity gradient increases and therefore the\u00a0water level must drop. Further along the\u00a0channel, part of\u00a0the\u00a0water flows through side openings into the\u00a0reservoirs, the\u00a0flow rate decreases and the\u00a0water level increases [2].<\/p>\n
The\u00a0model shows this at\u00a0all flow rates. At\u00a0low flow rates (377 and 566 l\/s) the\u00a0difference is\u00a0so small that this effect is\u00a0only theoretical and in\u00a0reality the\u00a0more significant difference in\u00a0water level is\u00a0caused by other factors (waves, wind). However, at\u00a0high flow rates (3,000, 6,000 l\/s), this effect is\u00a0quite significant. This is\u00a0shown in\u00a0the\u00a0following figures (Fig.\u00a03\u20137). The\u00a0colour scale shows the\u00a0difference between the\u00a0constant level approximation and the\u00a0simulated water level in\u00a0metres.<\/p>\n
All described effects can be seen even better in\u00a0Fig.\u00a07. The\u00a0height of\u00a0the\u00a0water level is\u00a0shown in\u00a0metres.<\/p>\n
<\/a>Fig.\u00a03. Simulated water level difference Q = 377 l\/s<\/h6>\n<\/a>Fig.\u00a04. Simulated water level difference Q = 566 l\/s<\/h6>\n<\/a>Fig.\u00a05. Simulated water level difference Q = 3,000 l\/s<\/h6>\n<\/a>Fig.\u00a06. Simulated water level difference Q = 6,000 l\/s<\/h6>\n<\/a>Fig.\u00a07. Simulated water level in\u00a0the\u00a0flow distribution object<\/h6>\nRESULTS<\/h2>\n
Fig.\u00a08\u201311 show the\u00a0contours of\u00a0the\u00a0simulated flow velocities in\u00a0the\u00a0channel cross-sections and in\u00a0the\u00a0openings, which can give some idea of\u00a0the\u00a0general flow pattern.<\/p>\n
At the\u00a0beginning of\u00a0the\u00a0channel, the\u00a0flow narrows quite significantly. It\u00a0means that the\u00a0first half of\u00a0the\u00a0first opening is\u00a0not fully utilized hydraulically. This is\u00a0again more important under high flow conditions. This effect could actually be less significant than in\u00a0the\u00a0model because there is\u00a0high turbulence in\u00a0the\u00a0aeration tank, which is\u00a0difficult to\u00a0assess in\u00a0the\u00a0model.<\/p>\n
The\u00a0colours represent the\u00a0overall velocity. Therefore, the\u00a0velocity in\u00a0the\u00a0last opening is\u00a0the\u00a0lowest. The\u00a0\u201cy\u201d component of\u00a0the\u00a0velocity is\u00a0quite significant in\u00a0the\u00a0first three openings [3].<\/p>\n
<\/a>Fig.\u00a08. Flow velocity contours Q = 377 l\/s<\/h6>\n<\/a>Fig.\u00a09. Flow velocity contours Q = 566 l\/s<\/h6>\nFig.\u00a010. Flow velocity contours Q = 3,000 l\/s<\/h6>\n<\/a>Fig.\u00a011. Flow velocity contours Q = 6,000 l\/s<\/h6>\nFlow distribution<\/h3>\n
Tab. 2 and Fig.\u00a012 show the\u00a0flow distribution under different flow conditions. Since no measured data were available, the\u00a0model could not be calibrated. The\u00a0sensitivity of\u00a0the\u00a0flows to\u00a0the\u00a0overflow height was adjusted only according to\u00a0the\u00a0theoretical flow curve. Preliminary results showed a\u00a0similar distribution of\u00a0flow under all flow conditions; however, at\u00a0low flows the\u00a0overflows were found to\u00a0be too sensitive to\u00a0overflow height. The\u00a0final results after appropriate adjustment of\u00a0this sensitivity are shown in\u00a0Tab. 2.<\/p>\n
Tab. 2. Flow distribution<\/a><\/h5>\n<\/a>Fig.\u00a012. Flow distribution<\/h6>\nThe\u00a0results show that the\u00a0flow distribution is\u00a0fairly evenly distributed at\u00a0low values; however, with increasing flow, the\u00a0unevenness of\u00a0the\u00a0distribution increases, which is\u00a0caused by the\u00a0differences in\u00a0the\u00a0water level described above [4].<\/p>\n
DISCUSSION<\/h2>\n
Since the\u00a0results showed that the\u00a0flow distribution is\u00a0not dependent on\u00a0the\u00a0flow itself, it was proposed to\u00a0solve the\u00a0problem by adjusting the\u00a0lengths of\u00a0the\u00a0overflows.<\/p>\n
The\u00a0introduction of\u00a0baffles across the\u00a0channel does not seem like a\u00a0good idea either. The\u00a0channel itself is\u00a0quite narrow and introducing any major obstructions into it would reduce its hydraulic capacity and rather make the\u00a0problem worse.<\/p>\n
The\u00a0best solution is\u00a0probably adjusting the\u00a0size of\u00a0the\u00a0openings at\u00a0the\u00a0channel bed to\u00a0distribute the\u00a0flow. Smaller openings at\u00a0the\u00a0end of\u00a0the\u00a0channel will cause a\u00a0hydraulic loss that will compensate for the\u00a0higher water level at\u00a0high flow rates. At\u00a0low flow rates, the\u00a0hydraulic loss will be small and the\u00a0flow distribution will not be affected.<\/p>\n
Setting the\u00a0size of\u00a0the\u00a0lower openings<\/h3>\n
Several simulations were performed to\u00a0find the\u00a0best possible combination of\u00a0opening sizes. The\u00a0optimization was based on\u00a0the\u00a0maximum flow rate (6,000\u00a0l\/s) and a\u00a0flow rate of\u00a0566 l\/s was used to\u00a0confirm the\u00a0good performance of\u00a0the\u00a0design at\u00a0low flow rate.<\/p>\n
The\u00a0simulations were performed iteratively. First, the\u00a0size of\u00a0the\u00a0openings was reduced to\u00a0half the\u00a0original size. The\u00a0original openings were very large (velocity 0.136 m\/s at\u00a0maximum flow rate), and although their size was halved, they did not cause much energy loss. The\u00a0flow through the\u00a0modified structure was simulated and the\u00a0flow rates into the\u00a0individual reservoirs were obtained.<\/p>\n
Optimization process<\/h3>\n
Tab. 3 and Fig.\u00a013 show the\u00a0simulation results of\u00a0the\u00a0above versions and show the\u00a0iteration process.<\/p>\n
Tab. 3. Comparison of\u00a0the\u00a0different phases of\u00a0the\u00a0iterative process (Qmax<\/sub>)<\/a><\/h5>\n<\/a>Fig.\u00a013. Example of\u00a0iterative process<\/h6>\nProposed improvement<\/h3>\n
The\u00a0proposed improvement is\u00a0shown in\u00a0Fig.\u00a014. The\u00a0red hatched areas show the\u00a0placement of\u00a0the\u00a0plates that close the\u00a0parts of\u00a0the\u00a0openings. In\u00a0the\u00a0simulations, these baffles were placed on\u00a0the\u00a0side of\u00a0the\u00a0channel and were aligned with the\u00a0channel wall.<\/p>\n
<\/a>Fig.\u00a014. Final dimensions of\u00a0the\u00a0proposed openings<\/h6>\n<\/a>Fig.\u00a015. Velocity contours of\u00a0the\u00a0flow pattern Q = 6,000 l\/s<\/h6>\nFunction principle<\/h3>\n
The\u00a0following figure (Fig.\u00a016) shows the\u00a0function of\u00a0the\u00a0baffles in\u00a0the\u00a0lower openings. Although the\u00a0water level rises along the\u00a0channel, the\u00a0water levels in\u00a0the\u00a0still chambers are almost equal. The\u00a0difference between the\u00a0water levels in\u00a0the\u00a0channel and in\u00a0the\u00a0still chamber is\u00a0due to\u00a0hydraulic losses caused by\u00a0the\u00a0baffles. The\u00a0colours in\u00a0the\u00a0figure show the\u00a0difference between the\u00a0approximate constant water level and the\u00a0calculated level.<\/p>\n
<\/a>Fig.\u00a016. The\u00a0water level in\u00a0the\u00a0distribution object<\/h6>\nCONCLUSION<\/h2>\n
The\u00a0following table and diagram (Tab. 4, Fig.\u00a017) show a\u00a0comparison of\u00a0the\u00a0simulation results for the\u00a0current state and the\u00a0final proposed improvement. For\u00a0improvement, only the\u00a0maximum flow (Qmax) and the\u00a0mean daily flow (Q24) have been simulated so far. It can be seen from the\u00a0results table that the\u00a0proposed state of\u00a0the\u00a0distribution facility meets the\u00a0conditions for an even distribution of\u00a0flows, and the\u00a0objectives of\u00a0the\u00a0research have thus been fulfilled. Considering the\u00a0fact that the\u00a0selected distribution facility is\u00a0commonly used in\u00a0the\u00a0field, the\u00a0results of\u00a0the\u00a0research can be easily applied in\u00a0practice, namely to\u00a0a larger number of\u00a0WWTP.<\/p>\n
Tab. 4. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/a><\/h5>\n<\/a>Fig.\u00a017. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/h6>\nOther possible improvements<\/h3>\n
This improvement shows that it is\u00a0possible to\u00a0reduce the\u00a0problem of\u00a0uneven flow distribution by introducing baffles into the\u00a0openings, the\u00a0installation of\u00a0which is\u00a0quick, simple, and without the\u00a0need for building modifications. Further attention in\u00a0possible follow-up research should be paid to\u00a0the\u00a0shape of\u00a0the\u00a0baffles.
\nIt cannot be ruled out that some sediments could accumulate in\u00a0the\u00a0quiet zones behind these baffles and especially in\u00a0the\u00a0corners (Fig.\u00a018), which could cause a\u00a0problem with sediment clogging the\u00a0inlet branches into the\u00a0reservoirs in\u00a0the\u00a0future. Clogging with sediment will most probably affect the\u00a0hydraulics of\u00a0the\u00a0distribution facility so that the\u00a0uneven flow distribution will occur again.<\/p>\n
<\/a>Fig.\u00a018. Sediment is\u00a0likely to\u00a0accumulate in\u00a0dead zones in\u00a0the\u00a0corners<\/h6>\nAcknowledgements<\/h3>\n
This article was supported by grant 3600.54.10\/2021 \u201c3D modelling of\u00a0selected
\nvariants of\u00a0flow distribution in\u00a0inlet galleries\u201d.<\/p>\n
<\/p>\n
The Czech version of this article was peer-reviewed, the English version was translated from\u00a0the Czech original by Environmental Translation Ltd.<\/p>\n","protected":false},"excerpt":{"rendered":"
The\u00a0main objective of\u00a0the\u00a0article was to\u00a0optimize the\u00a0facilities used to\u00a0distribute flows in\u00a0inlet galleries, which are used not only in\u00a0water treatment plants, but also in\u00a0wastewater treatment plants (WWTP). While working in\u00a0the\u00a0field of\u00a0WWTP, it\u00a0was found that there are no optimized facilities in\u00a0the\u00a0Czech Republic or globally for uniform distribution of\u00a0flows to\u00a0any number of\u00a0inlet branches into reservoirs of\u00a0the\u00a0same flow rate.\u00a0 Currently, in\u00a0most unregulated facilities, there are significant differences between the\u00a0various inlet branches to\u00a0the\u00a0reservoirs. In\u00a0regulated facilities, the\u00a0outlets must be regulated at\u00a0each change in\u00a0flow rate and, for changes in\u00a0the\u00a0number of\u00a0inlets to\u00a0the\u00a0reservoir (e.g., due to\u00a0reservoir shutdown), each outlet must be manually adjusted (e.g., using a\u00a0sluice gate) so that all inlets to\u00a0reservoirs have the\u00a0same flow rate. In\u00a0more modern cases, the\u00a0sluice is\u00a0equipped with an electric motor for changing the\u00a0position and a\u00a0probe sensing the\u00a0level. The\u00a0central unit then calculates the\u00a0flow rate in\u00a0the\u00a0individual reservoir inlets and adjusts the\u00a0position of\u00a0the\u00a0sluice gates so that the\u00a0same flow rate is\u00a0achieved everywhere. The\u00a0objective of\u00a0the\u00a0research was to\u00a0optimize the\u00a0distribution facility so that the\u00a0inlets to\u00a0the\u00a0reservoirs reach similar values for the\u00a0flow rate when both the\u00a0inflow to\u00a0the\u00a0distribution facility and the\u00a0number of\u00a0inlet branches to\u00a0the\u00a0reservoirs are changed, without significant regulation at\u00a0the\u00a0distribution facility. In\u00a0order to\u00a0make the\u00a0research easily applicable to\u00a0as many distribution facility as\u00a0possible, the\u00a0most commonly used flow distribution facilities (fountain spillway, flume with outlets fitted with a\u00a0sluice gate and probe for level monitoring, etc.) were selected to\u00a0address the\u00a0issue. Different flow conditions were simulated on\u00a0the\u00a0selected facilities (in different variants and shapes); after their analysis the\u00a0facilities were optimized in\u00a0order to\u00a0achieve the\u00a0most similar flows at\u00a0the\u00a0inlets to\u00a0the\u00a0individual reservoirs.<\/p>\n","protected":false},"author":8,"featured_media":18094,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[86],"tags":[3043,3044,3066,3067],"coauthors":[2448],"class_list":["post-21185","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydraulics-hydrology-and-hydrogeology","tag-cfd","tag-flow-3d","tag-flow-distribution","tag-inlet-galleries"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/comments?post=21185"}],"version-history":[{"count":6,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions"}],"predecessor-version":[{"id":32041,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions\/32041"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/18094"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=21185"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=21185"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=21185"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=21185"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
<\/a>Fig.\u00a04. Simulated water level difference Q = 566 l\/s<\/h6>\n<\/a>Fig.\u00a05. Simulated water level difference Q = 3,000 l\/s<\/h6>\n<\/a>Fig.\u00a06. Simulated water level difference Q = 6,000 l\/s<\/h6>\n<\/a>Fig.\u00a07. Simulated water level in\u00a0the\u00a0flow distribution object<\/h6>\nRESULTS<\/h2>\n
Fig.\u00a08\u201311 show the\u00a0contours of\u00a0the\u00a0simulated flow velocities in\u00a0the\u00a0channel cross-sections and in\u00a0the\u00a0openings, which can give some idea of\u00a0the\u00a0general flow pattern.<\/p>\n
At the\u00a0beginning of\u00a0the\u00a0channel, the\u00a0flow narrows quite significantly. It\u00a0means that the\u00a0first half of\u00a0the\u00a0first opening is\u00a0not fully utilized hydraulically. This is\u00a0again more important under high flow conditions. This effect could actually be less significant than in\u00a0the\u00a0model because there is\u00a0high turbulence in\u00a0the\u00a0aeration tank, which is\u00a0difficult to\u00a0assess in\u00a0the\u00a0model.<\/p>\n
The\u00a0colours represent the\u00a0overall velocity. Therefore, the\u00a0velocity in\u00a0the\u00a0last opening is\u00a0the\u00a0lowest. The\u00a0\u201cy\u201d component of\u00a0the\u00a0velocity is\u00a0quite significant in\u00a0the\u00a0first three openings [3].<\/p>\n
<\/a>Fig.\u00a08. Flow velocity contours Q = 377 l\/s<\/h6>\n<\/a>Fig.\u00a09. Flow velocity contours Q = 566 l\/s<\/h6>\nFig.\u00a010. Flow velocity contours Q = 3,000 l\/s<\/h6>\n<\/a>Fig.\u00a011. Flow velocity contours Q = 6,000 l\/s<\/h6>\nFlow distribution<\/h3>\n
Tab. 2 and Fig.\u00a012 show the\u00a0flow distribution under different flow conditions. Since no measured data were available, the\u00a0model could not be calibrated. The\u00a0sensitivity of\u00a0the\u00a0flows to\u00a0the\u00a0overflow height was adjusted only according to\u00a0the\u00a0theoretical flow curve. Preliminary results showed a\u00a0similar distribution of\u00a0flow under all flow conditions; however, at\u00a0low flows the\u00a0overflows were found to\u00a0be too sensitive to\u00a0overflow height. The\u00a0final results after appropriate adjustment of\u00a0this sensitivity are shown in\u00a0Tab. 2.<\/p>\n
Tab. 2. Flow distribution<\/a><\/h5>\n<\/a>Fig.\u00a012. Flow distribution<\/h6>\nThe\u00a0results show that the\u00a0flow distribution is\u00a0fairly evenly distributed at\u00a0low values; however, with increasing flow, the\u00a0unevenness of\u00a0the\u00a0distribution increases, which is\u00a0caused by the\u00a0differences in\u00a0the\u00a0water level described above [4].<\/p>\n
DISCUSSION<\/h2>\n
Since the\u00a0results showed that the\u00a0flow distribution is\u00a0not dependent on\u00a0the\u00a0flow itself, it was proposed to\u00a0solve the\u00a0problem by adjusting the\u00a0lengths of\u00a0the\u00a0overflows.<\/p>\n
The\u00a0introduction of\u00a0baffles across the\u00a0channel does not seem like a\u00a0good idea either. The\u00a0channel itself is\u00a0quite narrow and introducing any major obstructions into it would reduce its hydraulic capacity and rather make the\u00a0problem worse.<\/p>\n
The\u00a0best solution is\u00a0probably adjusting the\u00a0size of\u00a0the\u00a0openings at\u00a0the\u00a0channel bed to\u00a0distribute the\u00a0flow. Smaller openings at\u00a0the\u00a0end of\u00a0the\u00a0channel will cause a\u00a0hydraulic loss that will compensate for the\u00a0higher water level at\u00a0high flow rates. At\u00a0low flow rates, the\u00a0hydraulic loss will be small and the\u00a0flow distribution will not be affected.<\/p>\n
Setting the\u00a0size of\u00a0the\u00a0lower openings<\/h3>\n
Several simulations were performed to\u00a0find the\u00a0best possible combination of\u00a0opening sizes. The\u00a0optimization was based on\u00a0the\u00a0maximum flow rate (6,000\u00a0l\/s) and a\u00a0flow rate of\u00a0566 l\/s was used to\u00a0confirm the\u00a0good performance of\u00a0the\u00a0design at\u00a0low flow rate.<\/p>\n
The\u00a0simulations were performed iteratively. First, the\u00a0size of\u00a0the\u00a0openings was reduced to\u00a0half the\u00a0original size. The\u00a0original openings were very large (velocity 0.136 m\/s at\u00a0maximum flow rate), and although their size was halved, they did not cause much energy loss. The\u00a0flow through the\u00a0modified structure was simulated and the\u00a0flow rates into the\u00a0individual reservoirs were obtained.<\/p>\n
Optimization process<\/h3>\n
Tab. 3 and Fig.\u00a013 show the\u00a0simulation results of\u00a0the\u00a0above versions and show the\u00a0iteration process.<\/p>\n
Tab. 3. Comparison of\u00a0the\u00a0different phases of\u00a0the\u00a0iterative process (Qmax<\/sub>)<\/a><\/h5>\n<\/a>Fig.\u00a013. Example of\u00a0iterative process<\/h6>\nProposed improvement<\/h3>\n
The\u00a0proposed improvement is\u00a0shown in\u00a0Fig.\u00a014. The\u00a0red hatched areas show the\u00a0placement of\u00a0the\u00a0plates that close the\u00a0parts of\u00a0the\u00a0openings. In\u00a0the\u00a0simulations, these baffles were placed on\u00a0the\u00a0side of\u00a0the\u00a0channel and were aligned with the\u00a0channel wall.<\/p>\n
<\/a>Fig.\u00a014. Final dimensions of\u00a0the\u00a0proposed openings<\/h6>\n<\/a>Fig.\u00a015. Velocity contours of\u00a0the\u00a0flow pattern Q = 6,000 l\/s<\/h6>\nFunction principle<\/h3>\n
The\u00a0following figure (Fig.\u00a016) shows the\u00a0function of\u00a0the\u00a0baffles in\u00a0the\u00a0lower openings. Although the\u00a0water level rises along the\u00a0channel, the\u00a0water levels in\u00a0the\u00a0still chambers are almost equal. The\u00a0difference between the\u00a0water levels in\u00a0the\u00a0channel and in\u00a0the\u00a0still chamber is\u00a0due to\u00a0hydraulic losses caused by\u00a0the\u00a0baffles. The\u00a0colours in\u00a0the\u00a0figure show the\u00a0difference between the\u00a0approximate constant water level and the\u00a0calculated level.<\/p>\n
<\/a>Fig.\u00a016. The\u00a0water level in\u00a0the\u00a0distribution object<\/h6>\nCONCLUSION<\/h2>\n
The\u00a0following table and diagram (Tab. 4, Fig.\u00a017) show a\u00a0comparison of\u00a0the\u00a0simulation results for the\u00a0current state and the\u00a0final proposed improvement. For\u00a0improvement, only the\u00a0maximum flow (Qmax) and the\u00a0mean daily flow (Q24) have been simulated so far. It can be seen from the\u00a0results table that the\u00a0proposed state of\u00a0the\u00a0distribution facility meets the\u00a0conditions for an even distribution of\u00a0flows, and the\u00a0objectives of\u00a0the\u00a0research have thus been fulfilled. Considering the\u00a0fact that the\u00a0selected distribution facility is\u00a0commonly used in\u00a0the\u00a0field, the\u00a0results of\u00a0the\u00a0research can be easily applied in\u00a0practice, namely to\u00a0a larger number of\u00a0WWTP.<\/p>\n
Tab. 4. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/a><\/h5>\n<\/a>Fig.\u00a017. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/h6>\nOther possible improvements<\/h3>\n
This improvement shows that it is\u00a0possible to\u00a0reduce the\u00a0problem of\u00a0uneven flow distribution by introducing baffles into the\u00a0openings, the\u00a0installation of\u00a0which is\u00a0quick, simple, and without the\u00a0need for building modifications. Further attention in\u00a0possible follow-up research should be paid to\u00a0the\u00a0shape of\u00a0the\u00a0baffles.
\nIt cannot be ruled out that some sediments could accumulate in\u00a0the\u00a0quiet zones behind these baffles and especially in\u00a0the\u00a0corners (Fig.\u00a018), which could cause a\u00a0problem with sediment clogging the\u00a0inlet branches into the\u00a0reservoirs in\u00a0the\u00a0future. Clogging with sediment will most probably affect the\u00a0hydraulics of\u00a0the\u00a0distribution facility so that the\u00a0uneven flow distribution will occur again.<\/p>\n
<\/a>Fig.\u00a018. Sediment is\u00a0likely to\u00a0accumulate in\u00a0dead zones in\u00a0the\u00a0corners<\/h6>\nAcknowledgements<\/h3>\n
This article was supported by grant 3600.54.10\/2021 \u201c3D modelling of\u00a0selected
\nvariants of\u00a0flow distribution in\u00a0inlet galleries\u201d.<\/p>\n
<\/p>\n
The Czech version of this article was peer-reviewed, the English version was translated from\u00a0the Czech original by Environmental Translation Ltd.<\/p>\n","protected":false},"excerpt":{"rendered":"
The\u00a0main objective of\u00a0the\u00a0article was to\u00a0optimize the\u00a0facilities used to\u00a0distribute flows in\u00a0inlet galleries, which are used not only in\u00a0water treatment plants, but also in\u00a0wastewater treatment plants (WWTP). While working in\u00a0the\u00a0field of\u00a0WWTP, it\u00a0was found that there are no optimized facilities in\u00a0the\u00a0Czech Republic or globally for uniform distribution of\u00a0flows to\u00a0any number of\u00a0inlet branches into reservoirs of\u00a0the\u00a0same flow rate.\u00a0 Currently, in\u00a0most unregulated facilities, there are significant differences between the\u00a0various inlet branches to\u00a0the\u00a0reservoirs. In\u00a0regulated facilities, the\u00a0outlets must be regulated at\u00a0each change in\u00a0flow rate and, for changes in\u00a0the\u00a0number of\u00a0inlets to\u00a0the\u00a0reservoir (e.g., due to\u00a0reservoir shutdown), each outlet must be manually adjusted (e.g., using a\u00a0sluice gate) so that all inlets to\u00a0reservoirs have the\u00a0same flow rate. In\u00a0more modern cases, the\u00a0sluice is\u00a0equipped with an electric motor for changing the\u00a0position and a\u00a0probe sensing the\u00a0level. The\u00a0central unit then calculates the\u00a0flow rate in\u00a0the\u00a0individual reservoir inlets and adjusts the\u00a0position of\u00a0the\u00a0sluice gates so that the\u00a0same flow rate is\u00a0achieved everywhere. The\u00a0objective of\u00a0the\u00a0research was to\u00a0optimize the\u00a0distribution facility so that the\u00a0inlets to\u00a0the\u00a0reservoirs reach similar values for the\u00a0flow rate when both the\u00a0inflow to\u00a0the\u00a0distribution facility and the\u00a0number of\u00a0inlet branches to\u00a0the\u00a0reservoirs are changed, without significant regulation at\u00a0the\u00a0distribution facility. In\u00a0order to\u00a0make the\u00a0research easily applicable to\u00a0as many distribution facility as\u00a0possible, the\u00a0most commonly used flow distribution facilities (fountain spillway, flume with outlets fitted with a\u00a0sluice gate and probe for level monitoring, etc.) were selected to\u00a0address the\u00a0issue. Different flow conditions were simulated on\u00a0the\u00a0selected facilities (in different variants and shapes); after their analysis the\u00a0facilities were optimized in\u00a0order to\u00a0achieve the\u00a0most similar flows at\u00a0the\u00a0inlets to\u00a0the\u00a0individual reservoirs.<\/p>\n","protected":false},"author":8,"featured_media":18094,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[86],"tags":[3043,3044,3066,3067],"coauthors":[2448],"class_list":["post-21185","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydraulics-hydrology-and-hydrogeology","tag-cfd","tag-flow-3d","tag-flow-distribution","tag-inlet-galleries"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/comments?post=21185"}],"version-history":[{"count":6,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions"}],"predecessor-version":[{"id":32041,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions\/32041"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/18094"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=21185"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=21185"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=21185"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=21185"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
<\/a>Fig.\u00a06. Simulated water level difference Q = 6,000 l\/s<\/h6>\n<\/a>Fig.\u00a07. Simulated water level in\u00a0the\u00a0flow distribution object<\/h6>\nRESULTS<\/h2>\n
Fig.\u00a08\u201311 show the\u00a0contours of\u00a0the\u00a0simulated flow velocities in\u00a0the\u00a0channel cross-sections and in\u00a0the\u00a0openings, which can give some idea of\u00a0the\u00a0general flow pattern.<\/p>\n
At the\u00a0beginning of\u00a0the\u00a0channel, the\u00a0flow narrows quite significantly. It\u00a0means that the\u00a0first half of\u00a0the\u00a0first opening is\u00a0not fully utilized hydraulically. This is\u00a0again more important under high flow conditions. This effect could actually be less significant than in\u00a0the\u00a0model because there is\u00a0high turbulence in\u00a0the\u00a0aeration tank, which is\u00a0difficult to\u00a0assess in\u00a0the\u00a0model.<\/p>\n
The\u00a0colours represent the\u00a0overall velocity. Therefore, the\u00a0velocity in\u00a0the\u00a0last opening is\u00a0the\u00a0lowest. The\u00a0\u201cy\u201d component of\u00a0the\u00a0velocity is\u00a0quite significant in\u00a0the\u00a0first three openings [3].<\/p>\n
<\/a>Fig.\u00a08. Flow velocity contours Q = 377 l\/s<\/h6>\n<\/a>Fig.\u00a09. Flow velocity contours Q = 566 l\/s<\/h6>\nFig.\u00a010. Flow velocity contours Q = 3,000 l\/s<\/h6>\n<\/a>Fig.\u00a011. Flow velocity contours Q = 6,000 l\/s<\/h6>\nFlow distribution<\/h3>\n
Tab. 2 and Fig.\u00a012 show the\u00a0flow distribution under different flow conditions. Since no measured data were available, the\u00a0model could not be calibrated. The\u00a0sensitivity of\u00a0the\u00a0flows to\u00a0the\u00a0overflow height was adjusted only according to\u00a0the\u00a0theoretical flow curve. Preliminary results showed a\u00a0similar distribution of\u00a0flow under all flow conditions; however, at\u00a0low flows the\u00a0overflows were found to\u00a0be too sensitive to\u00a0overflow height. The\u00a0final results after appropriate adjustment of\u00a0this sensitivity are shown in\u00a0Tab. 2.<\/p>\n
Tab. 2. Flow distribution<\/a><\/h5>\n<\/a>Fig.\u00a012. Flow distribution<\/h6>\nThe\u00a0results show that the\u00a0flow distribution is\u00a0fairly evenly distributed at\u00a0low values; however, with increasing flow, the\u00a0unevenness of\u00a0the\u00a0distribution increases, which is\u00a0caused by the\u00a0differences in\u00a0the\u00a0water level described above [4].<\/p>\n
DISCUSSION<\/h2>\n
Since the\u00a0results showed that the\u00a0flow distribution is\u00a0not dependent on\u00a0the\u00a0flow itself, it was proposed to\u00a0solve the\u00a0problem by adjusting the\u00a0lengths of\u00a0the\u00a0overflows.<\/p>\n
The\u00a0introduction of\u00a0baffles across the\u00a0channel does not seem like a\u00a0good idea either. The\u00a0channel itself is\u00a0quite narrow and introducing any major obstructions into it would reduce its hydraulic capacity and rather make the\u00a0problem worse.<\/p>\n
The\u00a0best solution is\u00a0probably adjusting the\u00a0size of\u00a0the\u00a0openings at\u00a0the\u00a0channel bed to\u00a0distribute the\u00a0flow. Smaller openings at\u00a0the\u00a0end of\u00a0the\u00a0channel will cause a\u00a0hydraulic loss that will compensate for the\u00a0higher water level at\u00a0high flow rates. At\u00a0low flow rates, the\u00a0hydraulic loss will be small and the\u00a0flow distribution will not be affected.<\/p>\n
Setting the\u00a0size of\u00a0the\u00a0lower openings<\/h3>\n
Several simulations were performed to\u00a0find the\u00a0best possible combination of\u00a0opening sizes. The\u00a0optimization was based on\u00a0the\u00a0maximum flow rate (6,000\u00a0l\/s) and a\u00a0flow rate of\u00a0566 l\/s was used to\u00a0confirm the\u00a0good performance of\u00a0the\u00a0design at\u00a0low flow rate.<\/p>\n
The\u00a0simulations were performed iteratively. First, the\u00a0size of\u00a0the\u00a0openings was reduced to\u00a0half the\u00a0original size. The\u00a0original openings were very large (velocity 0.136 m\/s at\u00a0maximum flow rate), and although their size was halved, they did not cause much energy loss. The\u00a0flow through the\u00a0modified structure was simulated and the\u00a0flow rates into the\u00a0individual reservoirs were obtained.<\/p>\n
Optimization process<\/h3>\n
Tab. 3 and Fig.\u00a013 show the\u00a0simulation results of\u00a0the\u00a0above versions and show the\u00a0iteration process.<\/p>\n
Tab. 3. Comparison of\u00a0the\u00a0different phases of\u00a0the\u00a0iterative process (Qmax<\/sub>)<\/a><\/h5>\n<\/a>Fig.\u00a013. Example of\u00a0iterative process<\/h6>\nProposed improvement<\/h3>\n
The\u00a0proposed improvement is\u00a0shown in\u00a0Fig.\u00a014. The\u00a0red hatched areas show the\u00a0placement of\u00a0the\u00a0plates that close the\u00a0parts of\u00a0the\u00a0openings. In\u00a0the\u00a0simulations, these baffles were placed on\u00a0the\u00a0side of\u00a0the\u00a0channel and were aligned with the\u00a0channel wall.<\/p>\n
<\/a>Fig.\u00a014. Final dimensions of\u00a0the\u00a0proposed openings<\/h6>\n<\/a>Fig.\u00a015. Velocity contours of\u00a0the\u00a0flow pattern Q = 6,000 l\/s<\/h6>\nFunction principle<\/h3>\n
The\u00a0following figure (Fig.\u00a016) shows the\u00a0function of\u00a0the\u00a0baffles in\u00a0the\u00a0lower openings. Although the\u00a0water level rises along the\u00a0channel, the\u00a0water levels in\u00a0the\u00a0still chambers are almost equal. The\u00a0difference between the\u00a0water levels in\u00a0the\u00a0channel and in\u00a0the\u00a0still chamber is\u00a0due to\u00a0hydraulic losses caused by\u00a0the\u00a0baffles. The\u00a0colours in\u00a0the\u00a0figure show the\u00a0difference between the\u00a0approximate constant water level and the\u00a0calculated level.<\/p>\n
<\/a>Fig.\u00a016. The\u00a0water level in\u00a0the\u00a0distribution object<\/h6>\nCONCLUSION<\/h2>\n
The\u00a0following table and diagram (Tab. 4, Fig.\u00a017) show a\u00a0comparison of\u00a0the\u00a0simulation results for the\u00a0current state and the\u00a0final proposed improvement. For\u00a0improvement, only the\u00a0maximum flow (Qmax) and the\u00a0mean daily flow (Q24) have been simulated so far. It can be seen from the\u00a0results table that the\u00a0proposed state of\u00a0the\u00a0distribution facility meets the\u00a0conditions for an even distribution of\u00a0flows, and the\u00a0objectives of\u00a0the\u00a0research have thus been fulfilled. Considering the\u00a0fact that the\u00a0selected distribution facility is\u00a0commonly used in\u00a0the\u00a0field, the\u00a0results of\u00a0the\u00a0research can be easily applied in\u00a0practice, namely to\u00a0a larger number of\u00a0WWTP.<\/p>\n
Tab. 4. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/a><\/h5>\n<\/a>Fig.\u00a017. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/h6>\nOther possible improvements<\/h3>\n
This improvement shows that it is\u00a0possible to\u00a0reduce the\u00a0problem of\u00a0uneven flow distribution by introducing baffles into the\u00a0openings, the\u00a0installation of\u00a0which is\u00a0quick, simple, and without the\u00a0need for building modifications. Further attention in\u00a0possible follow-up research should be paid to\u00a0the\u00a0shape of\u00a0the\u00a0baffles.
\nIt cannot be ruled out that some sediments could accumulate in\u00a0the\u00a0quiet zones behind these baffles and especially in\u00a0the\u00a0corners (Fig.\u00a018), which could cause a\u00a0problem with sediment clogging the\u00a0inlet branches into the\u00a0reservoirs in\u00a0the\u00a0future. Clogging with sediment will most probably affect the\u00a0hydraulics of\u00a0the\u00a0distribution facility so that the\u00a0uneven flow distribution will occur again.<\/p>\n
<\/a>Fig.\u00a018. Sediment is\u00a0likely to\u00a0accumulate in\u00a0dead zones in\u00a0the\u00a0corners<\/h6>\nAcknowledgements<\/h3>\n
This article was supported by grant 3600.54.10\/2021 \u201c3D modelling of\u00a0selected
\nvariants of\u00a0flow distribution in\u00a0inlet galleries\u201d.<\/p>\n
<\/p>\n
The Czech version of this article was peer-reviewed, the English version was translated from\u00a0the Czech original by Environmental Translation Ltd.<\/p>\n","protected":false},"excerpt":{"rendered":"
The\u00a0main objective of\u00a0the\u00a0article was to\u00a0optimize the\u00a0facilities used to\u00a0distribute flows in\u00a0inlet galleries, which are used not only in\u00a0water treatment plants, but also in\u00a0wastewater treatment plants (WWTP). While working in\u00a0the\u00a0field of\u00a0WWTP, it\u00a0was found that there are no optimized facilities in\u00a0the\u00a0Czech Republic or globally for uniform distribution of\u00a0flows to\u00a0any number of\u00a0inlet branches into reservoirs of\u00a0the\u00a0same flow rate.\u00a0 Currently, in\u00a0most unregulated facilities, there are significant differences between the\u00a0various inlet branches to\u00a0the\u00a0reservoirs. In\u00a0regulated facilities, the\u00a0outlets must be regulated at\u00a0each change in\u00a0flow rate and, for changes in\u00a0the\u00a0number of\u00a0inlets to\u00a0the\u00a0reservoir (e.g., due to\u00a0reservoir shutdown), each outlet must be manually adjusted (e.g., using a\u00a0sluice gate) so that all inlets to\u00a0reservoirs have the\u00a0same flow rate. In\u00a0more modern cases, the\u00a0sluice is\u00a0equipped with an electric motor for changing the\u00a0position and a\u00a0probe sensing the\u00a0level. The\u00a0central unit then calculates the\u00a0flow rate in\u00a0the\u00a0individual reservoir inlets and adjusts the\u00a0position of\u00a0the\u00a0sluice gates so that the\u00a0same flow rate is\u00a0achieved everywhere. The\u00a0objective of\u00a0the\u00a0research was to\u00a0optimize the\u00a0distribution facility so that the\u00a0inlets to\u00a0the\u00a0reservoirs reach similar values for the\u00a0flow rate when both the\u00a0inflow to\u00a0the\u00a0distribution facility and the\u00a0number of\u00a0inlet branches to\u00a0the\u00a0reservoirs are changed, without significant regulation at\u00a0the\u00a0distribution facility. In\u00a0order to\u00a0make the\u00a0research easily applicable to\u00a0as many distribution facility as\u00a0possible, the\u00a0most commonly used flow distribution facilities (fountain spillway, flume with outlets fitted with a\u00a0sluice gate and probe for level monitoring, etc.) were selected to\u00a0address the\u00a0issue. Different flow conditions were simulated on\u00a0the\u00a0selected facilities (in different variants and shapes); after their analysis the\u00a0facilities were optimized in\u00a0order to\u00a0achieve the\u00a0most similar flows at\u00a0the\u00a0inlets to\u00a0the\u00a0individual reservoirs.<\/p>\n","protected":false},"author":8,"featured_media":18094,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[86],"tags":[3043,3044,3066,3067],"coauthors":[2448],"class_list":["post-21185","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydraulics-hydrology-and-hydrogeology","tag-cfd","tag-flow-3d","tag-flow-distribution","tag-inlet-galleries"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/comments?post=21185"}],"version-history":[{"count":6,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions"}],"predecessor-version":[{"id":32041,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions\/32041"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/18094"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=21185"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=21185"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=21185"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=21185"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
<\/a>Fig.\u00a08. Flow velocity contours Q = 377 l\/s<\/h6>\n<\/a>Fig.\u00a09. Flow velocity contours Q = 566 l\/s<\/h6>\nFig.\u00a010. Flow velocity contours Q = 3,000 l\/s<\/h6>\n<\/a>Fig.\u00a011. Flow velocity contours Q = 6,000 l\/s<\/h6>\nFlow distribution<\/h3>\n
Tab. 2 and Fig.\u00a012 show the\u00a0flow distribution under different flow conditions. Since no measured data were available, the\u00a0model could not be calibrated. The\u00a0sensitivity of\u00a0the\u00a0flows to\u00a0the\u00a0overflow height was adjusted only according to\u00a0the\u00a0theoretical flow curve. Preliminary results showed a\u00a0similar distribution of\u00a0flow under all flow conditions; however, at\u00a0low flows the\u00a0overflows were found to\u00a0be too sensitive to\u00a0overflow height. The\u00a0final results after appropriate adjustment of\u00a0this sensitivity are shown in\u00a0Tab. 2.<\/p>\n
Tab. 2. Flow distribution<\/a><\/h5>\n<\/a>Fig.\u00a012. Flow distribution<\/h6>\nThe\u00a0results show that the\u00a0flow distribution is\u00a0fairly evenly distributed at\u00a0low values; however, with increasing flow, the\u00a0unevenness of\u00a0the\u00a0distribution increases, which is\u00a0caused by the\u00a0differences in\u00a0the\u00a0water level described above [4].<\/p>\n
DISCUSSION<\/h2>\n
Since the\u00a0results showed that the\u00a0flow distribution is\u00a0not dependent on\u00a0the\u00a0flow itself, it was proposed to\u00a0solve the\u00a0problem by adjusting the\u00a0lengths of\u00a0the\u00a0overflows.<\/p>\n
The\u00a0introduction of\u00a0baffles across the\u00a0channel does not seem like a\u00a0good idea either. The\u00a0channel itself is\u00a0quite narrow and introducing any major obstructions into it would reduce its hydraulic capacity and rather make the\u00a0problem worse.<\/p>\n
The\u00a0best solution is\u00a0probably adjusting the\u00a0size of\u00a0the\u00a0openings at\u00a0the\u00a0channel bed to\u00a0distribute the\u00a0flow. Smaller openings at\u00a0the\u00a0end of\u00a0the\u00a0channel will cause a\u00a0hydraulic loss that will compensate for the\u00a0higher water level at\u00a0high flow rates. At\u00a0low flow rates, the\u00a0hydraulic loss will be small and the\u00a0flow distribution will not be affected.<\/p>\n
Setting the\u00a0size of\u00a0the\u00a0lower openings<\/h3>\n
Several simulations were performed to\u00a0find the\u00a0best possible combination of\u00a0opening sizes. The\u00a0optimization was based on\u00a0the\u00a0maximum flow rate (6,000\u00a0l\/s) and a\u00a0flow rate of\u00a0566 l\/s was used to\u00a0confirm the\u00a0good performance of\u00a0the\u00a0design at\u00a0low flow rate.<\/p>\n
The\u00a0simulations were performed iteratively. First, the\u00a0size of\u00a0the\u00a0openings was reduced to\u00a0half the\u00a0original size. The\u00a0original openings were very large (velocity 0.136 m\/s at\u00a0maximum flow rate), and although their size was halved, they did not cause much energy loss. The\u00a0flow through the\u00a0modified structure was simulated and the\u00a0flow rates into the\u00a0individual reservoirs were obtained.<\/p>\n
Optimization process<\/h3>\n
Tab. 3 and Fig.\u00a013 show the\u00a0simulation results of\u00a0the\u00a0above versions and show the\u00a0iteration process.<\/p>\n
Tab. 3. Comparison of\u00a0the\u00a0different phases of\u00a0the\u00a0iterative process (Qmax<\/sub>)<\/a><\/h5>\n<\/a>Fig.\u00a013. Example of\u00a0iterative process<\/h6>\nProposed improvement<\/h3>\n
The\u00a0proposed improvement is\u00a0shown in\u00a0Fig.\u00a014. The\u00a0red hatched areas show the\u00a0placement of\u00a0the\u00a0plates that close the\u00a0parts of\u00a0the\u00a0openings. In\u00a0the\u00a0simulations, these baffles were placed on\u00a0the\u00a0side of\u00a0the\u00a0channel and were aligned with the\u00a0channel wall.<\/p>\n
<\/a>Fig.\u00a014. Final dimensions of\u00a0the\u00a0proposed openings<\/h6>\n<\/a>Fig.\u00a015. Velocity contours of\u00a0the\u00a0flow pattern Q = 6,000 l\/s<\/h6>\nFunction principle<\/h3>\n
The\u00a0following figure (Fig.\u00a016) shows the\u00a0function of\u00a0the\u00a0baffles in\u00a0the\u00a0lower openings. Although the\u00a0water level rises along the\u00a0channel, the\u00a0water levels in\u00a0the\u00a0still chambers are almost equal. The\u00a0difference between the\u00a0water levels in\u00a0the\u00a0channel and in\u00a0the\u00a0still chamber is\u00a0due to\u00a0hydraulic losses caused by\u00a0the\u00a0baffles. The\u00a0colours in\u00a0the\u00a0figure show the\u00a0difference between the\u00a0approximate constant water level and the\u00a0calculated level.<\/p>\n
<\/a>Fig.\u00a016. The\u00a0water level in\u00a0the\u00a0distribution object<\/h6>\nCONCLUSION<\/h2>\n
The\u00a0following table and diagram (Tab. 4, Fig.\u00a017) show a\u00a0comparison of\u00a0the\u00a0simulation results for the\u00a0current state and the\u00a0final proposed improvement. For\u00a0improvement, only the\u00a0maximum flow (Qmax) and the\u00a0mean daily flow (Q24) have been simulated so far. It can be seen from the\u00a0results table that the\u00a0proposed state of\u00a0the\u00a0distribution facility meets the\u00a0conditions for an even distribution of\u00a0flows, and the\u00a0objectives of\u00a0the\u00a0research have thus been fulfilled. Considering the\u00a0fact that the\u00a0selected distribution facility is\u00a0commonly used in\u00a0the\u00a0field, the\u00a0results of\u00a0the\u00a0research can be easily applied in\u00a0practice, namely to\u00a0a larger number of\u00a0WWTP.<\/p>\n
Tab. 4. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/a><\/h5>\n<\/a>Fig.\u00a017. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/h6>\nOther possible improvements<\/h3>\n
This improvement shows that it is\u00a0possible to\u00a0reduce the\u00a0problem of\u00a0uneven flow distribution by introducing baffles into the\u00a0openings, the\u00a0installation of\u00a0which is\u00a0quick, simple, and without the\u00a0need for building modifications. Further attention in\u00a0possible follow-up research should be paid to\u00a0the\u00a0shape of\u00a0the\u00a0baffles.
\nIt cannot be ruled out that some sediments could accumulate in\u00a0the\u00a0quiet zones behind these baffles and especially in\u00a0the\u00a0corners (Fig.\u00a018), which could cause a\u00a0problem with sediment clogging the\u00a0inlet branches into the\u00a0reservoirs in\u00a0the\u00a0future. Clogging with sediment will most probably affect the\u00a0hydraulics of\u00a0the\u00a0distribution facility so that the\u00a0uneven flow distribution will occur again.<\/p>\n
<\/a>Fig.\u00a018. Sediment is\u00a0likely to\u00a0accumulate in\u00a0dead zones in\u00a0the\u00a0corners<\/h6>\nAcknowledgements<\/h3>\n
This article was supported by grant 3600.54.10\/2021 \u201c3D modelling of\u00a0selected
\nvariants of\u00a0flow distribution in\u00a0inlet galleries\u201d.<\/p>\n
<\/p>\n
The Czech version of this article was peer-reviewed, the English version was translated from\u00a0the Czech original by Environmental Translation Ltd.<\/p>\n","protected":false},"excerpt":{"rendered":"
The\u00a0main objective of\u00a0the\u00a0article was to\u00a0optimize the\u00a0facilities used to\u00a0distribute flows in\u00a0inlet galleries, which are used not only in\u00a0water treatment plants, but also in\u00a0wastewater treatment plants (WWTP). While working in\u00a0the\u00a0field of\u00a0WWTP, it\u00a0was found that there are no optimized facilities in\u00a0the\u00a0Czech Republic or globally for uniform distribution of\u00a0flows to\u00a0any number of\u00a0inlet branches into reservoirs of\u00a0the\u00a0same flow rate.\u00a0 Currently, in\u00a0most unregulated facilities, there are significant differences between the\u00a0various inlet branches to\u00a0the\u00a0reservoirs. In\u00a0regulated facilities, the\u00a0outlets must be regulated at\u00a0each change in\u00a0flow rate and, for changes in\u00a0the\u00a0number of\u00a0inlets to\u00a0the\u00a0reservoir (e.g., due to\u00a0reservoir shutdown), each outlet must be manually adjusted (e.g., using a\u00a0sluice gate) so that all inlets to\u00a0reservoirs have the\u00a0same flow rate. In\u00a0more modern cases, the\u00a0sluice is\u00a0equipped with an electric motor for changing the\u00a0position and a\u00a0probe sensing the\u00a0level. The\u00a0central unit then calculates the\u00a0flow rate in\u00a0the\u00a0individual reservoir inlets and adjusts the\u00a0position of\u00a0the\u00a0sluice gates so that the\u00a0same flow rate is\u00a0achieved everywhere. The\u00a0objective of\u00a0the\u00a0research was to\u00a0optimize the\u00a0distribution facility so that the\u00a0inlets to\u00a0the\u00a0reservoirs reach similar values for the\u00a0flow rate when both the\u00a0inflow to\u00a0the\u00a0distribution facility and the\u00a0number of\u00a0inlet branches to\u00a0the\u00a0reservoirs are changed, without significant regulation at\u00a0the\u00a0distribution facility. In\u00a0order to\u00a0make the\u00a0research easily applicable to\u00a0as many distribution facility as\u00a0possible, the\u00a0most commonly used flow distribution facilities (fountain spillway, flume with outlets fitted with a\u00a0sluice gate and probe for level monitoring, etc.) were selected to\u00a0address the\u00a0issue. Different flow conditions were simulated on\u00a0the\u00a0selected facilities (in different variants and shapes); after their analysis the\u00a0facilities were optimized in\u00a0order to\u00a0achieve the\u00a0most similar flows at\u00a0the\u00a0inlets to\u00a0the\u00a0individual reservoirs.<\/p>\n","protected":false},"author":8,"featured_media":18094,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[86],"tags":[3043,3044,3066,3067],"coauthors":[2448],"class_list":["post-21185","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydraulics-hydrology-and-hydrogeology","tag-cfd","tag-flow-3d","tag-flow-distribution","tag-inlet-galleries"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/comments?post=21185"}],"version-history":[{"count":6,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions"}],"predecessor-version":[{"id":32041,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions\/32041"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/18094"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=21185"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=21185"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=21185"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=21185"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
<\/a>Fig.\u00a011. Flow velocity contours Q = 6,000 l\/s<\/h6>\nFlow distribution<\/h3>\n
Tab. 2 and Fig.\u00a012 show the\u00a0flow distribution under different flow conditions. Since no measured data were available, the\u00a0model could not be calibrated. The\u00a0sensitivity of\u00a0the\u00a0flows to\u00a0the\u00a0overflow height was adjusted only according to\u00a0the\u00a0theoretical flow curve. Preliminary results showed a\u00a0similar distribution of\u00a0flow under all flow conditions; however, at\u00a0low flows the\u00a0overflows were found to\u00a0be too sensitive to\u00a0overflow height. The\u00a0final results after appropriate adjustment of\u00a0this sensitivity are shown in\u00a0Tab. 2.<\/p>\n
Tab. 2. Flow distribution<\/a><\/h5>\n<\/a>Fig.\u00a012. Flow distribution<\/h6>\nThe\u00a0results show that the\u00a0flow distribution is\u00a0fairly evenly distributed at\u00a0low values; however, with increasing flow, the\u00a0unevenness of\u00a0the\u00a0distribution increases, which is\u00a0caused by the\u00a0differences in\u00a0the\u00a0water level described above [4].<\/p>\n
DISCUSSION<\/h2>\n
Since the\u00a0results showed that the\u00a0flow distribution is\u00a0not dependent on\u00a0the\u00a0flow itself, it was proposed to\u00a0solve the\u00a0problem by adjusting the\u00a0lengths of\u00a0the\u00a0overflows.<\/p>\n
The\u00a0introduction of\u00a0baffles across the\u00a0channel does not seem like a\u00a0good idea either. The\u00a0channel itself is\u00a0quite narrow and introducing any major obstructions into it would reduce its hydraulic capacity and rather make the\u00a0problem worse.<\/p>\n
The\u00a0best solution is\u00a0probably adjusting the\u00a0size of\u00a0the\u00a0openings at\u00a0the\u00a0channel bed to\u00a0distribute the\u00a0flow. Smaller openings at\u00a0the\u00a0end of\u00a0the\u00a0channel will cause a\u00a0hydraulic loss that will compensate for the\u00a0higher water level at\u00a0high flow rates. At\u00a0low flow rates, the\u00a0hydraulic loss will be small and the\u00a0flow distribution will not be affected.<\/p>\n
Setting the\u00a0size of\u00a0the\u00a0lower openings<\/h3>\n
Several simulations were performed to\u00a0find the\u00a0best possible combination of\u00a0opening sizes. The\u00a0optimization was based on\u00a0the\u00a0maximum flow rate (6,000\u00a0l\/s) and a\u00a0flow rate of\u00a0566 l\/s was used to\u00a0confirm the\u00a0good performance of\u00a0the\u00a0design at\u00a0low flow rate.<\/p>\n
The\u00a0simulations were performed iteratively. First, the\u00a0size of\u00a0the\u00a0openings was reduced to\u00a0half the\u00a0original size. The\u00a0original openings were very large (velocity 0.136 m\/s at\u00a0maximum flow rate), and although their size was halved, they did not cause much energy loss. The\u00a0flow through the\u00a0modified structure was simulated and the\u00a0flow rates into the\u00a0individual reservoirs were obtained.<\/p>\n
Optimization process<\/h3>\n
Tab. 3 and Fig.\u00a013 show the\u00a0simulation results of\u00a0the\u00a0above versions and show the\u00a0iteration process.<\/p>\n
Tab. 3. Comparison of\u00a0the\u00a0different phases of\u00a0the\u00a0iterative process (Qmax<\/sub>)<\/a><\/h5>\n<\/a>Fig.\u00a013. Example of\u00a0iterative process<\/h6>\nProposed improvement<\/h3>\n
The\u00a0proposed improvement is\u00a0shown in\u00a0Fig.\u00a014. The\u00a0red hatched areas show the\u00a0placement of\u00a0the\u00a0plates that close the\u00a0parts of\u00a0the\u00a0openings. In\u00a0the\u00a0simulations, these baffles were placed on\u00a0the\u00a0side of\u00a0the\u00a0channel and were aligned with the\u00a0channel wall.<\/p>\n
<\/a>Fig.\u00a014. Final dimensions of\u00a0the\u00a0proposed openings<\/h6>\n<\/a>Fig.\u00a015. Velocity contours of\u00a0the\u00a0flow pattern Q = 6,000 l\/s<\/h6>\nFunction principle<\/h3>\n
The\u00a0following figure (Fig.\u00a016) shows the\u00a0function of\u00a0the\u00a0baffles in\u00a0the\u00a0lower openings. Although the\u00a0water level rises along the\u00a0channel, the\u00a0water levels in\u00a0the\u00a0still chambers are almost equal. The\u00a0difference between the\u00a0water levels in\u00a0the\u00a0channel and in\u00a0the\u00a0still chamber is\u00a0due to\u00a0hydraulic losses caused by\u00a0the\u00a0baffles. The\u00a0colours in\u00a0the\u00a0figure show the\u00a0difference between the\u00a0approximate constant water level and the\u00a0calculated level.<\/p>\n
<\/a>Fig.\u00a016. The\u00a0water level in\u00a0the\u00a0distribution object<\/h6>\nCONCLUSION<\/h2>\n
The\u00a0following table and diagram (Tab. 4, Fig.\u00a017) show a\u00a0comparison of\u00a0the\u00a0simulation results for the\u00a0current state and the\u00a0final proposed improvement. For\u00a0improvement, only the\u00a0maximum flow (Qmax) and the\u00a0mean daily flow (Q24) have been simulated so far. It can be seen from the\u00a0results table that the\u00a0proposed state of\u00a0the\u00a0distribution facility meets the\u00a0conditions for an even distribution of\u00a0flows, and the\u00a0objectives of\u00a0the\u00a0research have thus been fulfilled. Considering the\u00a0fact that the\u00a0selected distribution facility is\u00a0commonly used in\u00a0the\u00a0field, the\u00a0results of\u00a0the\u00a0research can be easily applied in\u00a0practice, namely to\u00a0a larger number of\u00a0WWTP.<\/p>\n
Tab. 4. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/a><\/h5>\n<\/a>Fig.\u00a017. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/h6>\nOther possible improvements<\/h3>\n
This improvement shows that it is\u00a0possible to\u00a0reduce the\u00a0problem of\u00a0uneven flow distribution by introducing baffles into the\u00a0openings, the\u00a0installation of\u00a0which is\u00a0quick, simple, and without the\u00a0need for building modifications. Further attention in\u00a0possible follow-up research should be paid to\u00a0the\u00a0shape of\u00a0the\u00a0baffles.
\nIt cannot be ruled out that some sediments could accumulate in\u00a0the\u00a0quiet zones behind these baffles and especially in\u00a0the\u00a0corners (Fig.\u00a018), which could cause a\u00a0problem with sediment clogging the\u00a0inlet branches into the\u00a0reservoirs in\u00a0the\u00a0future. Clogging with sediment will most probably affect the\u00a0hydraulics of\u00a0the\u00a0distribution facility so that the\u00a0uneven flow distribution will occur again.<\/p>\n
<\/a>Fig.\u00a018. Sediment is\u00a0likely to\u00a0accumulate in\u00a0dead zones in\u00a0the\u00a0corners<\/h6>\nAcknowledgements<\/h3>\n
This article was supported by grant 3600.54.10\/2021 \u201c3D modelling of\u00a0selected
\nvariants of\u00a0flow distribution in\u00a0inlet galleries\u201d.<\/p>\n
<\/p>\n
The Czech version of this article was peer-reviewed, the English version was translated from\u00a0the Czech original by Environmental Translation Ltd.<\/p>\n","protected":false},"excerpt":{"rendered":"
The\u00a0main objective of\u00a0the\u00a0article was to\u00a0optimize the\u00a0facilities used to\u00a0distribute flows in\u00a0inlet galleries, which are used not only in\u00a0water treatment plants, but also in\u00a0wastewater treatment plants (WWTP). While working in\u00a0the\u00a0field of\u00a0WWTP, it\u00a0was found that there are no optimized facilities in\u00a0the\u00a0Czech Republic or globally for uniform distribution of\u00a0flows to\u00a0any number of\u00a0inlet branches into reservoirs of\u00a0the\u00a0same flow rate.\u00a0 Currently, in\u00a0most unregulated facilities, there are significant differences between the\u00a0various inlet branches to\u00a0the\u00a0reservoirs. In\u00a0regulated facilities, the\u00a0outlets must be regulated at\u00a0each change in\u00a0flow rate and, for changes in\u00a0the\u00a0number of\u00a0inlets to\u00a0the\u00a0reservoir (e.g., due to\u00a0reservoir shutdown), each outlet must be manually adjusted (e.g., using a\u00a0sluice gate) so that all inlets to\u00a0reservoirs have the\u00a0same flow rate. In\u00a0more modern cases, the\u00a0sluice is\u00a0equipped with an electric motor for changing the\u00a0position and a\u00a0probe sensing the\u00a0level. The\u00a0central unit then calculates the\u00a0flow rate in\u00a0the\u00a0individual reservoir inlets and adjusts the\u00a0position of\u00a0the\u00a0sluice gates so that the\u00a0same flow rate is\u00a0achieved everywhere. The\u00a0objective of\u00a0the\u00a0research was to\u00a0optimize the\u00a0distribution facility so that the\u00a0inlets to\u00a0the\u00a0reservoirs reach similar values for the\u00a0flow rate when both the\u00a0inflow to\u00a0the\u00a0distribution facility and the\u00a0number of\u00a0inlet branches to\u00a0the\u00a0reservoirs are changed, without significant regulation at\u00a0the\u00a0distribution facility. In\u00a0order to\u00a0make the\u00a0research easily applicable to\u00a0as many distribution facility as\u00a0possible, the\u00a0most commonly used flow distribution facilities (fountain spillway, flume with outlets fitted with a\u00a0sluice gate and probe for level monitoring, etc.) were selected to\u00a0address the\u00a0issue. Different flow conditions were simulated on\u00a0the\u00a0selected facilities (in different variants and shapes); after their analysis the\u00a0facilities were optimized in\u00a0order to\u00a0achieve the\u00a0most similar flows at\u00a0the\u00a0inlets to\u00a0the\u00a0individual reservoirs.<\/p>\n","protected":false},"author":8,"featured_media":18094,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[86],"tags":[3043,3044,3066,3067],"coauthors":[2448],"class_list":["post-21185","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydraulics-hydrology-and-hydrogeology","tag-cfd","tag-flow-3d","tag-flow-distribution","tag-inlet-galleries"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/comments?post=21185"}],"version-history":[{"count":6,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions"}],"predecessor-version":[{"id":32041,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions\/32041"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/18094"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=21185"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=21185"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=21185"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=21185"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
<\/a><\/h5>\n<\/a>Fig.\u00a012. Flow distribution<\/h6>\nThe\u00a0results show that the\u00a0flow distribution is\u00a0fairly evenly distributed at\u00a0low values; however, with increasing flow, the\u00a0unevenness of\u00a0the\u00a0distribution increases, which is\u00a0caused by the\u00a0differences in\u00a0the\u00a0water level described above [4].<\/p>\n
DISCUSSION<\/h2>\n
Since the\u00a0results showed that the\u00a0flow distribution is\u00a0not dependent on\u00a0the\u00a0flow itself, it was proposed to\u00a0solve the\u00a0problem by adjusting the\u00a0lengths of\u00a0the\u00a0overflows.<\/p>\n
The\u00a0introduction of\u00a0baffles across the\u00a0channel does not seem like a\u00a0good idea either. The\u00a0channel itself is\u00a0quite narrow and introducing any major obstructions into it would reduce its hydraulic capacity and rather make the\u00a0problem worse.<\/p>\n
The\u00a0best solution is\u00a0probably adjusting the\u00a0size of\u00a0the\u00a0openings at\u00a0the\u00a0channel bed to\u00a0distribute the\u00a0flow. Smaller openings at\u00a0the\u00a0end of\u00a0the\u00a0channel will cause a\u00a0hydraulic loss that will compensate for the\u00a0higher water level at\u00a0high flow rates. At\u00a0low flow rates, the\u00a0hydraulic loss will be small and the\u00a0flow distribution will not be affected.<\/p>\n
Setting the\u00a0size of\u00a0the\u00a0lower openings<\/h3>\n
Several simulations were performed to\u00a0find the\u00a0best possible combination of\u00a0opening sizes. The\u00a0optimization was based on\u00a0the\u00a0maximum flow rate (6,000\u00a0l\/s) and a\u00a0flow rate of\u00a0566 l\/s was used to\u00a0confirm the\u00a0good performance of\u00a0the\u00a0design at\u00a0low flow rate.<\/p>\n
The\u00a0simulations were performed iteratively. First, the\u00a0size of\u00a0the\u00a0openings was reduced to\u00a0half the\u00a0original size. The\u00a0original openings were very large (velocity 0.136 m\/s at\u00a0maximum flow rate), and although their size was halved, they did not cause much energy loss. The\u00a0flow through the\u00a0modified structure was simulated and the\u00a0flow rates into the\u00a0individual reservoirs were obtained.<\/p>\n
Optimization process<\/h3>\n
Tab. 3 and Fig.\u00a013 show the\u00a0simulation results of\u00a0the\u00a0above versions and show the\u00a0iteration process.<\/p>\n
Tab. 3. Comparison of\u00a0the\u00a0different phases of\u00a0the\u00a0iterative process (Qmax<\/sub>)<\/a><\/h5>\n<\/a>Fig.\u00a013. Example of\u00a0iterative process<\/h6>\nProposed improvement<\/h3>\n
The\u00a0proposed improvement is\u00a0shown in\u00a0Fig.\u00a014. The\u00a0red hatched areas show the\u00a0placement of\u00a0the\u00a0plates that close the\u00a0parts of\u00a0the\u00a0openings. In\u00a0the\u00a0simulations, these baffles were placed on\u00a0the\u00a0side of\u00a0the\u00a0channel and were aligned with the\u00a0channel wall.<\/p>\n
<\/a>Fig.\u00a014. Final dimensions of\u00a0the\u00a0proposed openings<\/h6>\n<\/a>Fig.\u00a015. Velocity contours of\u00a0the\u00a0flow pattern Q = 6,000 l\/s<\/h6>\nFunction principle<\/h3>\n
The\u00a0following figure (Fig.\u00a016) shows the\u00a0function of\u00a0the\u00a0baffles in\u00a0the\u00a0lower openings. Although the\u00a0water level rises along the\u00a0channel, the\u00a0water levels in\u00a0the\u00a0still chambers are almost equal. The\u00a0difference between the\u00a0water levels in\u00a0the\u00a0channel and in\u00a0the\u00a0still chamber is\u00a0due to\u00a0hydraulic losses caused by\u00a0the\u00a0baffles. The\u00a0colours in\u00a0the\u00a0figure show the\u00a0difference between the\u00a0approximate constant water level and the\u00a0calculated level.<\/p>\n
<\/a>Fig.\u00a016. The\u00a0water level in\u00a0the\u00a0distribution object<\/h6>\nCONCLUSION<\/h2>\n
The\u00a0following table and diagram (Tab. 4, Fig.\u00a017) show a\u00a0comparison of\u00a0the\u00a0simulation results for the\u00a0current state and the\u00a0final proposed improvement. For\u00a0improvement, only the\u00a0maximum flow (Qmax) and the\u00a0mean daily flow (Q24) have been simulated so far. It can be seen from the\u00a0results table that the\u00a0proposed state of\u00a0the\u00a0distribution facility meets the\u00a0conditions for an even distribution of\u00a0flows, and the\u00a0objectives of\u00a0the\u00a0research have thus been fulfilled. Considering the\u00a0fact that the\u00a0selected distribution facility is\u00a0commonly used in\u00a0the\u00a0field, the\u00a0results of\u00a0the\u00a0research can be easily applied in\u00a0practice, namely to\u00a0a larger number of\u00a0WWTP.<\/p>\n
Tab. 4. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/a><\/h5>\n<\/a>Fig.\u00a017. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/h6>\nOther possible improvements<\/h3>\n
This improvement shows that it is\u00a0possible to\u00a0reduce the\u00a0problem of\u00a0uneven flow distribution by introducing baffles into the\u00a0openings, the\u00a0installation of\u00a0which is\u00a0quick, simple, and without the\u00a0need for building modifications. Further attention in\u00a0possible follow-up research should be paid to\u00a0the\u00a0shape of\u00a0the\u00a0baffles.
\nIt cannot be ruled out that some sediments could accumulate in\u00a0the\u00a0quiet zones behind these baffles and especially in\u00a0the\u00a0corners (Fig.\u00a018), which could cause a\u00a0problem with sediment clogging the\u00a0inlet branches into the\u00a0reservoirs in\u00a0the\u00a0future. Clogging with sediment will most probably affect the\u00a0hydraulics of\u00a0the\u00a0distribution facility so that the\u00a0uneven flow distribution will occur again.<\/p>\n
<\/a>Fig.\u00a018. Sediment is\u00a0likely to\u00a0accumulate in\u00a0dead zones in\u00a0the\u00a0corners<\/h6>\nAcknowledgements<\/h3>\n
This article was supported by grant 3600.54.10\/2021 \u201c3D modelling of\u00a0selected
\nvariants of\u00a0flow distribution in\u00a0inlet galleries\u201d.<\/p>\n
<\/p>\n
The Czech version of this article was peer-reviewed, the English version was translated from\u00a0the Czech original by Environmental Translation Ltd.<\/p>\n","protected":false},"excerpt":{"rendered":"
The\u00a0main objective of\u00a0the\u00a0article was to\u00a0optimize the\u00a0facilities used to\u00a0distribute flows in\u00a0inlet galleries, which are used not only in\u00a0water treatment plants, but also in\u00a0wastewater treatment plants (WWTP). While working in\u00a0the\u00a0field of\u00a0WWTP, it\u00a0was found that there are no optimized facilities in\u00a0the\u00a0Czech Republic or globally for uniform distribution of\u00a0flows to\u00a0any number of\u00a0inlet branches into reservoirs of\u00a0the\u00a0same flow rate.\u00a0 Currently, in\u00a0most unregulated facilities, there are significant differences between the\u00a0various inlet branches to\u00a0the\u00a0reservoirs. In\u00a0regulated facilities, the\u00a0outlets must be regulated at\u00a0each change in\u00a0flow rate and, for changes in\u00a0the\u00a0number of\u00a0inlets to\u00a0the\u00a0reservoir (e.g., due to\u00a0reservoir shutdown), each outlet must be manually adjusted (e.g., using a\u00a0sluice gate) so that all inlets to\u00a0reservoirs have the\u00a0same flow rate. In\u00a0more modern cases, the\u00a0sluice is\u00a0equipped with an electric motor for changing the\u00a0position and a\u00a0probe sensing the\u00a0level. The\u00a0central unit then calculates the\u00a0flow rate in\u00a0the\u00a0individual reservoir inlets and adjusts the\u00a0position of\u00a0the\u00a0sluice gates so that the\u00a0same flow rate is\u00a0achieved everywhere. The\u00a0objective of\u00a0the\u00a0research was to\u00a0optimize the\u00a0distribution facility so that the\u00a0inlets to\u00a0the\u00a0reservoirs reach similar values for the\u00a0flow rate when both the\u00a0inflow to\u00a0the\u00a0distribution facility and the\u00a0number of\u00a0inlet branches to\u00a0the\u00a0reservoirs are changed, without significant regulation at\u00a0the\u00a0distribution facility. In\u00a0order to\u00a0make the\u00a0research easily applicable to\u00a0as many distribution facility as\u00a0possible, the\u00a0most commonly used flow distribution facilities (fountain spillway, flume with outlets fitted with a\u00a0sluice gate and probe for level monitoring, etc.) were selected to\u00a0address the\u00a0issue. Different flow conditions were simulated on\u00a0the\u00a0selected facilities (in different variants and shapes); after their analysis the\u00a0facilities were optimized in\u00a0order to\u00a0achieve the\u00a0most similar flows at\u00a0the\u00a0inlets to\u00a0the\u00a0individual reservoirs.<\/p>\n","protected":false},"author":8,"featured_media":18094,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[86],"tags":[3043,3044,3066,3067],"coauthors":[2448],"class_list":["post-21185","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydraulics-hydrology-and-hydrogeology","tag-cfd","tag-flow-3d","tag-flow-distribution","tag-inlet-galleries"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/comments?post=21185"}],"version-history":[{"count":6,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions"}],"predecessor-version":[{"id":32041,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions\/32041"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/18094"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=21185"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=21185"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=21185"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=21185"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
<\/a><\/h5>\n<\/a>Fig.\u00a013. Example of\u00a0iterative process<\/h6>\nProposed improvement<\/h3>\n
The\u00a0proposed improvement is\u00a0shown in\u00a0Fig.\u00a014. The\u00a0red hatched areas show the\u00a0placement of\u00a0the\u00a0plates that close the\u00a0parts of\u00a0the\u00a0openings. In\u00a0the\u00a0simulations, these baffles were placed on\u00a0the\u00a0side of\u00a0the\u00a0channel and were aligned with the\u00a0channel wall.<\/p>\n
<\/a>Fig.\u00a014. Final dimensions of\u00a0the\u00a0proposed openings<\/h6>\n<\/a>Fig.\u00a015. Velocity contours of\u00a0the\u00a0flow pattern Q = 6,000 l\/s<\/h6>\nFunction principle<\/h3>\n
The\u00a0following figure (Fig.\u00a016) shows the\u00a0function of\u00a0the\u00a0baffles in\u00a0the\u00a0lower openings. Although the\u00a0water level rises along the\u00a0channel, the\u00a0water levels in\u00a0the\u00a0still chambers are almost equal. The\u00a0difference between the\u00a0water levels in\u00a0the\u00a0channel and in\u00a0the\u00a0still chamber is\u00a0due to\u00a0hydraulic losses caused by\u00a0the\u00a0baffles. The\u00a0colours in\u00a0the\u00a0figure show the\u00a0difference between the\u00a0approximate constant water level and the\u00a0calculated level.<\/p>\n
<\/a>Fig.\u00a016. The\u00a0water level in\u00a0the\u00a0distribution object<\/h6>\nCONCLUSION<\/h2>\n
The\u00a0following table and diagram (Tab. 4, Fig.\u00a017) show a\u00a0comparison of\u00a0the\u00a0simulation results for the\u00a0current state and the\u00a0final proposed improvement. For\u00a0improvement, only the\u00a0maximum flow (Qmax) and the\u00a0mean daily flow (Q24) have been simulated so far. It can be seen from the\u00a0results table that the\u00a0proposed state of\u00a0the\u00a0distribution facility meets the\u00a0conditions for an even distribution of\u00a0flows, and the\u00a0objectives of\u00a0the\u00a0research have thus been fulfilled. Considering the\u00a0fact that the\u00a0selected distribution facility is\u00a0commonly used in\u00a0the\u00a0field, the\u00a0results of\u00a0the\u00a0research can be easily applied in\u00a0practice, namely to\u00a0a larger number of\u00a0WWTP.<\/p>\n
Tab. 4. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/a><\/h5>\n<\/a>Fig.\u00a017. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/h6>\nOther possible improvements<\/h3>\n
This improvement shows that it is\u00a0possible to\u00a0reduce the\u00a0problem of\u00a0uneven flow distribution by introducing baffles into the\u00a0openings, the\u00a0installation of\u00a0which is\u00a0quick, simple, and without the\u00a0need for building modifications. Further attention in\u00a0possible follow-up research should be paid to\u00a0the\u00a0shape of\u00a0the\u00a0baffles.
\nIt cannot be ruled out that some sediments could accumulate in\u00a0the\u00a0quiet zones behind these baffles and especially in\u00a0the\u00a0corners (Fig.\u00a018), which could cause a\u00a0problem with sediment clogging the\u00a0inlet branches into the\u00a0reservoirs in\u00a0the\u00a0future. Clogging with sediment will most probably affect the\u00a0hydraulics of\u00a0the\u00a0distribution facility so that the\u00a0uneven flow distribution will occur again.<\/p>\n
<\/a>Fig.\u00a018. Sediment is\u00a0likely to\u00a0accumulate in\u00a0dead zones in\u00a0the\u00a0corners<\/h6>\nAcknowledgements<\/h3>\n
This article was supported by grant 3600.54.10\/2021 \u201c3D modelling of\u00a0selected
\nvariants of\u00a0flow distribution in\u00a0inlet galleries\u201d.<\/p>\n
<\/p>\n
The Czech version of this article was peer-reviewed, the English version was translated from\u00a0the Czech original by Environmental Translation Ltd.<\/p>\n","protected":false},"excerpt":{"rendered":"
The\u00a0main objective of\u00a0the\u00a0article was to\u00a0optimize the\u00a0facilities used to\u00a0distribute flows in\u00a0inlet galleries, which are used not only in\u00a0water treatment plants, but also in\u00a0wastewater treatment plants (WWTP). While working in\u00a0the\u00a0field of\u00a0WWTP, it\u00a0was found that there are no optimized facilities in\u00a0the\u00a0Czech Republic or globally for uniform distribution of\u00a0flows to\u00a0any number of\u00a0inlet branches into reservoirs of\u00a0the\u00a0same flow rate.\u00a0 Currently, in\u00a0most unregulated facilities, there are significant differences between the\u00a0various inlet branches to\u00a0the\u00a0reservoirs. In\u00a0regulated facilities, the\u00a0outlets must be regulated at\u00a0each change in\u00a0flow rate and, for changes in\u00a0the\u00a0number of\u00a0inlets to\u00a0the\u00a0reservoir (e.g., due to\u00a0reservoir shutdown), each outlet must be manually adjusted (e.g., using a\u00a0sluice gate) so that all inlets to\u00a0reservoirs have the\u00a0same flow rate. In\u00a0more modern cases, the\u00a0sluice is\u00a0equipped with an electric motor for changing the\u00a0position and a\u00a0probe sensing the\u00a0level. The\u00a0central unit then calculates the\u00a0flow rate in\u00a0the\u00a0individual reservoir inlets and adjusts the\u00a0position of\u00a0the\u00a0sluice gates so that the\u00a0same flow rate is\u00a0achieved everywhere. The\u00a0objective of\u00a0the\u00a0research was to\u00a0optimize the\u00a0distribution facility so that the\u00a0inlets to\u00a0the\u00a0reservoirs reach similar values for the\u00a0flow rate when both the\u00a0inflow to\u00a0the\u00a0distribution facility and the\u00a0number of\u00a0inlet branches to\u00a0the\u00a0reservoirs are changed, without significant regulation at\u00a0the\u00a0distribution facility. In\u00a0order to\u00a0make the\u00a0research easily applicable to\u00a0as many distribution facility as\u00a0possible, the\u00a0most commonly used flow distribution facilities (fountain spillway, flume with outlets fitted with a\u00a0sluice gate and probe for level monitoring, etc.) were selected to\u00a0address the\u00a0issue. Different flow conditions were simulated on\u00a0the\u00a0selected facilities (in different variants and shapes); after their analysis the\u00a0facilities were optimized in\u00a0order to\u00a0achieve the\u00a0most similar flows at\u00a0the\u00a0inlets to\u00a0the\u00a0individual reservoirs.<\/p>\n","protected":false},"author":8,"featured_media":18094,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[86],"tags":[3043,3044,3066,3067],"coauthors":[2448],"class_list":["post-21185","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydraulics-hydrology-and-hydrogeology","tag-cfd","tag-flow-3d","tag-flow-distribution","tag-inlet-galleries"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/comments?post=21185"}],"version-history":[{"count":6,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions"}],"predecessor-version":[{"id":32041,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions\/32041"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/18094"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=21185"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=21185"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=21185"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=21185"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
<\/a>Fig.\u00a014. Final dimensions of\u00a0the\u00a0proposed openings<\/h6>\n<\/a>Fig.\u00a015. Velocity contours of\u00a0the\u00a0flow pattern Q = 6,000 l\/s<\/h6>\nFunction principle<\/h3>\n
The\u00a0following figure (Fig.\u00a016) shows the\u00a0function of\u00a0the\u00a0baffles in\u00a0the\u00a0lower openings. Although the\u00a0water level rises along the\u00a0channel, the\u00a0water levels in\u00a0the\u00a0still chambers are almost equal. The\u00a0difference between the\u00a0water levels in\u00a0the\u00a0channel and in\u00a0the\u00a0still chamber is\u00a0due to\u00a0hydraulic losses caused by\u00a0the\u00a0baffles. The\u00a0colours in\u00a0the\u00a0figure show the\u00a0difference between the\u00a0approximate constant water level and the\u00a0calculated level.<\/p>\n
<\/a>Fig.\u00a016. The\u00a0water level in\u00a0the\u00a0distribution object<\/h6>\nCONCLUSION<\/h2>\n
The\u00a0following table and diagram (Tab. 4, Fig.\u00a017) show a\u00a0comparison of\u00a0the\u00a0simulation results for the\u00a0current state and the\u00a0final proposed improvement. For\u00a0improvement, only the\u00a0maximum flow (Qmax) and the\u00a0mean daily flow (Q24) have been simulated so far. It can be seen from the\u00a0results table that the\u00a0proposed state of\u00a0the\u00a0distribution facility meets the\u00a0conditions for an even distribution of\u00a0flows, and the\u00a0objectives of\u00a0the\u00a0research have thus been fulfilled. Considering the\u00a0fact that the\u00a0selected distribution facility is\u00a0commonly used in\u00a0the\u00a0field, the\u00a0results of\u00a0the\u00a0research can be easily applied in\u00a0practice, namely to\u00a0a larger number of\u00a0WWTP.<\/p>\n
Tab. 4. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/a><\/h5>\n<\/a>Fig.\u00a017. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/h6>\nOther possible improvements<\/h3>\n
This improvement shows that it is\u00a0possible to\u00a0reduce the\u00a0problem of\u00a0uneven flow distribution by introducing baffles into the\u00a0openings, the\u00a0installation of\u00a0which is\u00a0quick, simple, and without the\u00a0need for building modifications. Further attention in\u00a0possible follow-up research should be paid to\u00a0the\u00a0shape of\u00a0the\u00a0baffles.
\nIt cannot be ruled out that some sediments could accumulate in\u00a0the\u00a0quiet zones behind these baffles and especially in\u00a0the\u00a0corners (Fig.\u00a018), which could cause a\u00a0problem with sediment clogging the\u00a0inlet branches into the\u00a0reservoirs in\u00a0the\u00a0future. Clogging with sediment will most probably affect the\u00a0hydraulics of\u00a0the\u00a0distribution facility so that the\u00a0uneven flow distribution will occur again.<\/p>\n
<\/a>Fig.\u00a018. Sediment is\u00a0likely to\u00a0accumulate in\u00a0dead zones in\u00a0the\u00a0corners<\/h6>\nAcknowledgements<\/h3>\n
This article was supported by grant 3600.54.10\/2021 \u201c3D modelling of\u00a0selected
\nvariants of\u00a0flow distribution in\u00a0inlet galleries\u201d.<\/p>\n
<\/p>\n
The Czech version of this article was peer-reviewed, the English version was translated from\u00a0the Czech original by Environmental Translation Ltd.<\/p>\n","protected":false},"excerpt":{"rendered":"
The\u00a0main objective of\u00a0the\u00a0article was to\u00a0optimize the\u00a0facilities used to\u00a0distribute flows in\u00a0inlet galleries, which are used not only in\u00a0water treatment plants, but also in\u00a0wastewater treatment plants (WWTP). While working in\u00a0the\u00a0field of\u00a0WWTP, it\u00a0was found that there are no optimized facilities in\u00a0the\u00a0Czech Republic or globally for uniform distribution of\u00a0flows to\u00a0any number of\u00a0inlet branches into reservoirs of\u00a0the\u00a0same flow rate.\u00a0 Currently, in\u00a0most unregulated facilities, there are significant differences between the\u00a0various inlet branches to\u00a0the\u00a0reservoirs. In\u00a0regulated facilities, the\u00a0outlets must be regulated at\u00a0each change in\u00a0flow rate and, for changes in\u00a0the\u00a0number of\u00a0inlets to\u00a0the\u00a0reservoir (e.g., due to\u00a0reservoir shutdown), each outlet must be manually adjusted (e.g., using a\u00a0sluice gate) so that all inlets to\u00a0reservoirs have the\u00a0same flow rate. In\u00a0more modern cases, the\u00a0sluice is\u00a0equipped with an electric motor for changing the\u00a0position and a\u00a0probe sensing the\u00a0level. The\u00a0central unit then calculates the\u00a0flow rate in\u00a0the\u00a0individual reservoir inlets and adjusts the\u00a0position of\u00a0the\u00a0sluice gates so that the\u00a0same flow rate is\u00a0achieved everywhere. The\u00a0objective of\u00a0the\u00a0research was to\u00a0optimize the\u00a0distribution facility so that the\u00a0inlets to\u00a0the\u00a0reservoirs reach similar values for the\u00a0flow rate when both the\u00a0inflow to\u00a0the\u00a0distribution facility and the\u00a0number of\u00a0inlet branches to\u00a0the\u00a0reservoirs are changed, without significant regulation at\u00a0the\u00a0distribution facility. In\u00a0order to\u00a0make the\u00a0research easily applicable to\u00a0as many distribution facility as\u00a0possible, the\u00a0most commonly used flow distribution facilities (fountain spillway, flume with outlets fitted with a\u00a0sluice gate and probe for level monitoring, etc.) were selected to\u00a0address the\u00a0issue. Different flow conditions were simulated on\u00a0the\u00a0selected facilities (in different variants and shapes); after their analysis the\u00a0facilities were optimized in\u00a0order to\u00a0achieve the\u00a0most similar flows at\u00a0the\u00a0inlets to\u00a0the\u00a0individual reservoirs.<\/p>\n","protected":false},"author":8,"featured_media":18094,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[86],"tags":[3043,3044,3066,3067],"coauthors":[2448],"class_list":["post-21185","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydraulics-hydrology-and-hydrogeology","tag-cfd","tag-flow-3d","tag-flow-distribution","tag-inlet-galleries"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/comments?post=21185"}],"version-history":[{"count":6,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions"}],"predecessor-version":[{"id":32041,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions\/32041"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/18094"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=21185"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=21185"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=21185"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=21185"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
<\/a>Fig.\u00a016. The\u00a0water level in\u00a0the\u00a0distribution object<\/h6>\nCONCLUSION<\/h2>\n
The\u00a0following table and diagram (Tab. 4, Fig.\u00a017) show a\u00a0comparison of\u00a0the\u00a0simulation results for the\u00a0current state and the\u00a0final proposed improvement. For\u00a0improvement, only the\u00a0maximum flow (Qmax) and the\u00a0mean daily flow (Q24) have been simulated so far. It can be seen from the\u00a0results table that the\u00a0proposed state of\u00a0the\u00a0distribution facility meets the\u00a0conditions for an even distribution of\u00a0flows, and the\u00a0objectives of\u00a0the\u00a0research have thus been fulfilled. Considering the\u00a0fact that the\u00a0selected distribution facility is\u00a0commonly used in\u00a0the\u00a0field, the\u00a0results of\u00a0the\u00a0research can be easily applied in\u00a0practice, namely to\u00a0a larger number of\u00a0WWTP.<\/p>\n
Tab. 4. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/a><\/h5>\n<\/a>Fig.\u00a017. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/h6>\nOther possible improvements<\/h3>\n
This improvement shows that it is\u00a0possible to\u00a0reduce the\u00a0problem of\u00a0uneven flow distribution by introducing baffles into the\u00a0openings, the\u00a0installation of\u00a0which is\u00a0quick, simple, and without the\u00a0need for building modifications. Further attention in\u00a0possible follow-up research should be paid to\u00a0the\u00a0shape of\u00a0the\u00a0baffles.
\nIt cannot be ruled out that some sediments could accumulate in\u00a0the\u00a0quiet zones behind these baffles and especially in\u00a0the\u00a0corners (Fig.\u00a018), which could cause a\u00a0problem with sediment clogging the\u00a0inlet branches into the\u00a0reservoirs in\u00a0the\u00a0future. Clogging with sediment will most probably affect the\u00a0hydraulics of\u00a0the\u00a0distribution facility so that the\u00a0uneven flow distribution will occur again.<\/p>\n
<\/a>Fig.\u00a018. Sediment is\u00a0likely to\u00a0accumulate in\u00a0dead zones in\u00a0the\u00a0corners<\/h6>\nAcknowledgements<\/h3>\n
This article was supported by grant 3600.54.10\/2021 \u201c3D modelling of\u00a0selected
\nvariants of\u00a0flow distribution in\u00a0inlet galleries\u201d.<\/p>\n
<\/p>\n
The Czech version of this article was peer-reviewed, the English version was translated from\u00a0the Czech original by Environmental Translation Ltd.<\/p>\n","protected":false},"excerpt":{"rendered":"
The\u00a0main objective of\u00a0the\u00a0article was to\u00a0optimize the\u00a0facilities used to\u00a0distribute flows in\u00a0inlet galleries, which are used not only in\u00a0water treatment plants, but also in\u00a0wastewater treatment plants (WWTP). While working in\u00a0the\u00a0field of\u00a0WWTP, it\u00a0was found that there are no optimized facilities in\u00a0the\u00a0Czech Republic or globally for uniform distribution of\u00a0flows to\u00a0any number of\u00a0inlet branches into reservoirs of\u00a0the\u00a0same flow rate.\u00a0 Currently, in\u00a0most unregulated facilities, there are significant differences between the\u00a0various inlet branches to\u00a0the\u00a0reservoirs. In\u00a0regulated facilities, the\u00a0outlets must be regulated at\u00a0each change in\u00a0flow rate and, for changes in\u00a0the\u00a0number of\u00a0inlets to\u00a0the\u00a0reservoir (e.g., due to\u00a0reservoir shutdown), each outlet must be manually adjusted (e.g., using a\u00a0sluice gate) so that all inlets to\u00a0reservoirs have the\u00a0same flow rate. In\u00a0more modern cases, the\u00a0sluice is\u00a0equipped with an electric motor for changing the\u00a0position and a\u00a0probe sensing the\u00a0level. The\u00a0central unit then calculates the\u00a0flow rate in\u00a0the\u00a0individual reservoir inlets and adjusts the\u00a0position of\u00a0the\u00a0sluice gates so that the\u00a0same flow rate is\u00a0achieved everywhere. The\u00a0objective of\u00a0the\u00a0research was to\u00a0optimize the\u00a0distribution facility so that the\u00a0inlets to\u00a0the\u00a0reservoirs reach similar values for the\u00a0flow rate when both the\u00a0inflow to\u00a0the\u00a0distribution facility and the\u00a0number of\u00a0inlet branches to\u00a0the\u00a0reservoirs are changed, without significant regulation at\u00a0the\u00a0distribution facility. In\u00a0order to\u00a0make the\u00a0research easily applicable to\u00a0as many distribution facility as\u00a0possible, the\u00a0most commonly used flow distribution facilities (fountain spillway, flume with outlets fitted with a\u00a0sluice gate and probe for level monitoring, etc.) were selected to\u00a0address the\u00a0issue. Different flow conditions were simulated on\u00a0the\u00a0selected facilities (in different variants and shapes); after their analysis the\u00a0facilities were optimized in\u00a0order to\u00a0achieve the\u00a0most similar flows at\u00a0the\u00a0inlets to\u00a0the\u00a0individual reservoirs.<\/p>\n","protected":false},"author":8,"featured_media":18094,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[86],"tags":[3043,3044,3066,3067],"coauthors":[2448],"class_list":["post-21185","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydraulics-hydrology-and-hydrogeology","tag-cfd","tag-flow-3d","tag-flow-distribution","tag-inlet-galleries"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/comments?post=21185"}],"version-history":[{"count":6,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions"}],"predecessor-version":[{"id":32041,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions\/32041"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/18094"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=21185"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=21185"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=21185"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=21185"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
<\/a>Fig.\u00a017. Comparison of\u00a0the\u00a0current situation and proposed improvements<\/h6>\nOther possible improvements<\/h3>\n
This improvement shows that it is\u00a0possible to\u00a0reduce the\u00a0problem of\u00a0uneven flow distribution by introducing baffles into the\u00a0openings, the\u00a0installation of\u00a0which is\u00a0quick, simple, and without the\u00a0need for building modifications. Further attention in\u00a0possible follow-up research should be paid to\u00a0the\u00a0shape of\u00a0the\u00a0baffles.
\nIt cannot be ruled out that some sediments could accumulate in\u00a0the\u00a0quiet zones behind these baffles and especially in\u00a0the\u00a0corners (Fig.\u00a018), which could cause a\u00a0problem with sediment clogging the\u00a0inlet branches into the\u00a0reservoirs in\u00a0the\u00a0future. Clogging with sediment will most probably affect the\u00a0hydraulics of\u00a0the\u00a0distribution facility so that the\u00a0uneven flow distribution will occur again.<\/p>\n
<\/a>Fig.\u00a018. Sediment is\u00a0likely to\u00a0accumulate in\u00a0dead zones in\u00a0the\u00a0corners<\/h6>\nAcknowledgements<\/h3>\n
This article was supported by grant 3600.54.10\/2021 \u201c3D modelling of\u00a0selected
\nvariants of\u00a0flow distribution in\u00a0inlet galleries\u201d.<\/p>\n
<\/p>\n
The Czech version of this article was peer-reviewed, the English version was translated from\u00a0the Czech original by Environmental Translation Ltd.<\/p>\n","protected":false},"excerpt":{"rendered":"
The\u00a0main objective of\u00a0the\u00a0article was to\u00a0optimize the\u00a0facilities used to\u00a0distribute flows in\u00a0inlet galleries, which are used not only in\u00a0water treatment plants, but also in\u00a0wastewater treatment plants (WWTP). While working in\u00a0the\u00a0field of\u00a0WWTP, it\u00a0was found that there are no optimized facilities in\u00a0the\u00a0Czech Republic or globally for uniform distribution of\u00a0flows to\u00a0any number of\u00a0inlet branches into reservoirs of\u00a0the\u00a0same flow rate.\u00a0 Currently, in\u00a0most unregulated facilities, there are significant differences between the\u00a0various inlet branches to\u00a0the\u00a0reservoirs. In\u00a0regulated facilities, the\u00a0outlets must be regulated at\u00a0each change in\u00a0flow rate and, for changes in\u00a0the\u00a0number of\u00a0inlets to\u00a0the\u00a0reservoir (e.g., due to\u00a0reservoir shutdown), each outlet must be manually adjusted (e.g., using a\u00a0sluice gate) so that all inlets to\u00a0reservoirs have the\u00a0same flow rate. In\u00a0more modern cases, the\u00a0sluice is\u00a0equipped with an electric motor for changing the\u00a0position and a\u00a0probe sensing the\u00a0level. The\u00a0central unit then calculates the\u00a0flow rate in\u00a0the\u00a0individual reservoir inlets and adjusts the\u00a0position of\u00a0the\u00a0sluice gates so that the\u00a0same flow rate is\u00a0achieved everywhere. The\u00a0objective of\u00a0the\u00a0research was to\u00a0optimize the\u00a0distribution facility so that the\u00a0inlets to\u00a0the\u00a0reservoirs reach similar values for the\u00a0flow rate when both the\u00a0inflow to\u00a0the\u00a0distribution facility and the\u00a0number of\u00a0inlet branches to\u00a0the\u00a0reservoirs are changed, without significant regulation at\u00a0the\u00a0distribution facility. In\u00a0order to\u00a0make the\u00a0research easily applicable to\u00a0as many distribution facility as\u00a0possible, the\u00a0most commonly used flow distribution facilities (fountain spillway, flume with outlets fitted with a\u00a0sluice gate and probe for level monitoring, etc.) were selected to\u00a0address the\u00a0issue. Different flow conditions were simulated on\u00a0the\u00a0selected facilities (in different variants and shapes); after their analysis the\u00a0facilities were optimized in\u00a0order to\u00a0achieve the\u00a0most similar flows at\u00a0the\u00a0inlets to\u00a0the\u00a0individual reservoirs.<\/p>\n","protected":false},"author":8,"featured_media":18094,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[86],"tags":[3043,3044,3066,3067],"coauthors":[2448],"class_list":["post-21185","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydraulics-hydrology-and-hydrogeology","tag-cfd","tag-flow-3d","tag-flow-distribution","tag-inlet-galleries"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/comments?post=21185"}],"version-history":[{"count":6,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions"}],"predecessor-version":[{"id":32041,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/21185\/revisions\/32041"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/18094"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=21185"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=21185"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=21185"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=21185"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\nvariants of\u00a0flow distribution in\u00a0inlet galleries\u201d.<\/p>\n