The\u00a0measurements within\u00a0the\u00a0Doksany weir were carried out on a physical model at a scale of\u00a01 : 12.5 and on a mathematical 3D model in\u00a0Ansys CFX. Both models were set up for ordinary and extraordinary situations, i.e. without aeration and with exceeding the\u00a0maximum operating level. For the\u00a0Strakonice weir, a physical model was built at a scale of\u00a01 : 7, on which levels and flows were measured for ordinary operating conditions.<\/span><\/p>\n In\u00a0connection with climate change, there has been an increase in\u00a0the\u00a0frequency of\u00a0intense rainfall events, which often lead to sudden flooding. These extreme meteorological phenomena pose a significant risk to both property and human lives. Given this reality, it is essential to refine coefficients of\u00a0overflow discharge, which are used to determine discharge rating curves. These discharge rating curves used in\u00a0operation regulations and automated control systems are more in\u00a0line with reality, which helps in\u00a0the\u00a0operational management of\u00a0flooding through hydraulic structures, e.g. to improve transformation at reservoirs, where decisions need to be made quickly and efficiently about operations in\u00a0water management systems to minimise possible negative impacts.<\/span><\/p>\n The\u00a0aim of\u00a0the\u00a0research is to complement the\u00a0existing curves of\u00a0overflow coefficients for higher degree of\u00a0downstream flooding and for extraordinary conditions. The\u00a0research includes a comparison of\u00a0different types of\u00a0baffles and a mathematical description of\u00a0flap gate movement.<\/span><\/p>\n Flap gates are currently the\u00a0most common type of\u00a0movable gate found on weirs and dams in\u00a0the\u00a0Czech Republic; simultaneously, they can also be described as the\u00a0most widely used type of\u00a0gate in\u00a0the\u00a0reconstruction of\u00a0weirs along the\u00a0Elbe\u2013Vltava waterway and other weirs in\u00a0the\u00a0Czech Republic, as well as in\u00a0overflow control structures of\u00a0dams such as Nechranice Reservoir. This is due to their advantages, particularly the\u00a0possibility of\u00a0precise operation and the\u00a0cost-effectiveness of\u00a0both construction and operation.<\/span><\/p>\n Flap gates were the\u00a0subject of\u00a0research by Jaroslav \u010c\u00e1belka, Gerhard Wickert, and Gerhard Schmausser at the\u00a0end of\u00a0the\u00a020th century [1, 2]. However, these publications focus only on ordinary conditions without significant influence from downstream flooding.<\/span><\/p>\n For this reason, and in\u00a0view of\u00a0the\u00a0accelerating pace of\u00a0climate change, which is bringing more frequent occurrences of\u00a0extreme rainfall, Czech research has been extended to include ordinary conditions with greater downstream influence as well as exceptional situations. Exceptional situations refer to conditions in\u00a0which the\u00a0water level in\u00a0the\u00a0watercourse rises above the\u00a0ordinary operating level due to increased flow, or when the\u00a0aeration pipe of\u00a0a flap weir becomes clogged, resulting in\u00a0increased discharge over the\u00a0control structure.<\/span><\/p>\n As part of\u00a0the\u00a0research, sectional physical models of\u00a0weirs fitted with flap gates were constructed at the\u00a0Water Management Experimental Centre of\u00a0the\u00a0Faculty of\u00a0Civil Engineering at CTU in\u00a0Prague. At the\u00a0same time, 3D mathematical models were created for one of\u00a0the\u00a0weirs. The\u00a0aim was to analyse the\u00a0hydraulic behaviour of\u00a0the\u00a0overflows under various flow rates, geometric modifications to the\u00a0overflow crest of\u00a0the\u00a0flap gate, and water flow around the\u00a0overflows. The\u00a0measured and calculated values were used to obtain\u00a0water surface profiles, which could be compared across the\u00a0different methods, including numerical calculations based on graphs from existing research.<\/span><\/p>\n Doksany hydraulic structure (Fig.\u00a01<\/span>) is located on the\u00a0Oh\u0159e river in\u00a0the\u00a0southern part of\u00a0the\u00a0municipality of\u00a0Doksany in\u00a0the\u00a0\u00dast\u00ed nad Labem Region. The\u00a0components of\u00a0the\u00a0structure include a machine room, a weir, a small hydropower plant, and a fish pass. The\u00a0weir consists of\u00a0a reinforced concrete structure with a movable control element mounted on top \u2013 namely, a steel gate in\u00a0the\u00a0form of\u00a0a hollow flap. Flap gates have large U-profile baffles and small L-profile baffles installed on the\u00a0overflow crest. The\u00a0raising structure has a total of\u00a0two overflow spans, each 20\u00a0m long, with a fixed overflow elevation of\u00a0150.81 m a.s.l. The\u00a0maximum water level of\u00a0the\u00a0weir reservoir, according to the\u00a0operational regulations, is 153.25\u00a0m\u00a0a.s.l. At each weir span, the\u00a0pier houses a DN300 aeration pipe and an opening for the\u00a0flap locking pin. Below the\u00a0weir, there is a 13.2-metre-long stilling basin, 1.6\u00a0m deep, ending with three steps and a raised threshold that is 0.3\u00a0m above the\u00a0reinforced channel bed. The\u00a0riverbed area around the\u00a0weir is reinforced with stone paving and topped with a stone embankment. It should be noted that the\u00a0height difference between the\u00a0upstream and downstream beds is 1\u00a0m, which significantly limits the\u00a0influence of\u00a0downstream overflow flooding.<\/span><\/p>\n <\/p>\n Strakonice hydraulic structure \u2013 also known as Strakonice stabilising weir \u2013 is located on the Otava river in the town of Strakonice in the South Bohemian Region. The structure consists of a reinforced concrete weir with two spans, each 20 m\u00a0<\/span>long, on which a pair of\u00a0flap gates with seals are mounted between the\u00a0transverse braces. It is equipped with lifting mechanisms, machine rooms above the\u00a0pillars, and a sluiceway that also functions as a fish pass. The\u00a0fixed overflow elevation is 387.00\u00a0m\u00a0a.s.l., which is the\u00a0same as the\u00a0bed elevation downstream of\u00a0the\u00a0overflow. The\u00a0ordinary operational reservoir level is 388.30\u00a0m\u00a0a.s.l., while the\u00a0maximum reservoir level, according to operational regulations, is at an elevation of\u00a0388.50\u00a0metres\u00a0a.s.l. The\u00a0downstream stilling basin\u00a0was 6\u00a0m long and 0.8 m deep. In\u00a02019, the\u00a0stilling basin\u00a0was reconstructed to meet hydraulic conditions required for sufficient dissipation of\u00a0the\u00a0kinetic energy of\u00a0water flowing over the\u00a0weir gate.<\/span><\/p>\n Hydraulic phenomena, water flow, and hydraulic characteristics can be studied on an actual hydraulic structure; however, for practical reasons, such research is significantly more difficult, and therefore, investigations are conducted on a scaled-down model in\u00a0the\u00a0laboratory. Initial, boundary, and limiting conditions are determined by dimensional, force, and mass analysis, which are based on the\u00a0conditions for studying phenomena on the\u00a0model using Froude\u2019s law of\u00a0mechanical similarity\u00a0[3].<\/span><\/p>\n Two physical models were constructed for measurements in\u00a0the\u00a0water management laboratory. The\u00a0first model, 0.4 m wide, representing Strakonice weir with a flap gate and seal, was built at a scale of\u00a01 : 7. On this model, water levels and flow rates were measured for various flap positions with increased downstream influence, as the\u00a0difference in\u00a0bed elevation between the\u00a0upstream and downstream <\/span>sides is 0 m. The\u00a0second model, 0.52 m wide and built at a scale of\u00a01 : 12.5, represented Doksany weir (Fig.\u00a03<\/span><\/em>). Water levels and flow rates were measured on this model for extraordinary situations, such as when the\u00a0aeration pipe is non-functional or when the\u00a0reservoir level exceeds the\u00a0maximum operating level.<\/span><\/p>\n Within\u00a0this model, different types of\u00a0baffles (types RV.x and RM.x) were also mutually assessed in\u00a0terms of\u00a0flow capacity (Fig.\u00a04<\/span><\/em>). However, due to the\u00a0model conditions, it was not possible to determine the\u00a0impact on the\u00a0overflow coefficient. The\u00a0conversion of\u00a0individual characteristics from physical models to actual hydraulic structures can be performed using the\u00a0following formulas:<\/span><\/p>\n <\/p>\n A mathematical 3D model was only created for Doksany weir (Fig.\u00a05<\/span><\/em>), with the\u00a0same conditions maintained as in\u00a0the\u00a0physical model, except for the\u00a0model width; only half of\u00a0the\u00a0weir field with a length of\u00a010 m was modelled. The\u00a0computational mesh was created using ICEM CFD software, and all calculations were performed in\u00a0Ansys CFX. In\u00a0connection with the\u00a0use of\u00a0the\u00a0symmetry function in\u00a0the\u00a0model, subsequent verification revealed that a certain\u00a0degree of\u00a0error had been introduced into the\u00a0model, resulting in\u00a0a higher flow capacity [4, 5].<\/span><\/p>\n The\u00a0aim of\u00a0selecting a computational method for determining water flow and discharge was to identify calculation uncertainties using CFD technologies. The\u00a0choice of\u00a0an appropriate method is crucial for minimising uncertainty in\u00a0mathematical modelling; it is essential to carefully select the\u00a0method with regard to hydraulic behaviour and to minimise risks during the\u00a0measurement of\u00a0flow in\u00a0the\u00a0hydraulic structure\u00a0[6].<\/span><\/p>\n <\/p>\n In\u00a0engineering practice, when calculating overflow discharge over a flap gate, water levels are often measured from the\u00a0flap\u2019s pivot point at its lowest edge. However, this approach does not accurately reflect reality. This introduces an error into the\u00a0calculation of\u00a0the\u00a0overflow head due to a discrepancy in\u00a0the\u00a0tilt of\u00a0the\u00a0flap gate compared to its actual position, which affects the\u00a0discharge curve \u2013 a critical factor for operational control. As a result, operations at\u00a0the\u00a0hydraulic structure become inaccurate, leading to reduced effectiveness of\u00a0operational control within\u00a0water management systems.<\/span><\/p>\n For this reason, equations describing the\u00a0movement of\u00a0a flap gate were derived, incorporating eccentricity between the\u00a0gate plate and the\u00a0bearing axis (Fig.\u00a06<\/span>). It should be noted that the\u00a0equations relate to the\u00a0movement of\u00a0a flap gate with a radius of\u00a0R = 2.25*H. Equations were also derived for the\u00a0simultaneous movement of\u00a0baffles together with the\u00a0flap gate. All equations, including their application within\u00a0calculation tools, are described in\u00a0detail in\u00a0the\u00a0Master\u2019s thesis titled Hydraulic Analysis of\u00a0Flap Gates and Jambor Sills<\/span>\u00a0[7].<\/span><\/p>\n The\u00a0measured and calculated data from the\u00a0Doksany weir models for extraordinary situations were inserted into an existing graph with curves by J. \u010c\u00e1belka (CR), which allows the\u00a0coefficient of\u00a0the\u00a0overfall \u00b5p\u03c3<\/span> to be read (Fig.\u00a07<\/span><\/em>). These data are presented in\u00a0the\u00a0form of\u00a0points from the\u00a0physical model (PM) and the\u00a0mathematical model (MM), and it is not possible to construct curves from them, as each measured value corresponds to a different pressure and level of\u00a0aeration beneath the\u00a0flap, which cannot be measured in\u00a0practice during extraordinary situations. For this reason, the\u00a0values in\u00a0the\u00a0graph (Fig.\u00a07<\/span><\/em>) are divided according to the\u00a0degree of\u00a0downstream flooding for practical application, as this degree plays a more significant role in\u00a0calculations for other hydraulic structures.<\/span><\/p>\n <\/p>\n Similarly, data from measurements on the\u00a0physical model of\u00a0Strakonice weir were inserted into the\u00a0same graph by J. \u010c\u00e1belka (Fig.\u00a08<\/span><\/em>). However, in\u00a0this case, it was possible to fit curves to the\u00a0data due to the\u00a0typical situation involving a\u00a0raised downstream level. Compared to the\u00a0current research (CR), where the\u00a0ratio H\u03c3<\/span><\/sub>\/H reached a value of\u00a00.7, it was now possible to achieve a value of\u00a0up to 0.92 on the\u00a0physical model (PM), which will aid in\u00a0the\u00a0calculation of\u00a0discharge curves for other hydraulic structures, such as Kl\u00e1\u0161terec weir on the\u00a0Oh\u0159e river. The\u00a0use of\u00a0the\u00a0overfall coefficient is evident in\u00a0the\u00a0following overflow equation:<\/span><\/p>\n where:<\/p>\n Q\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 is\u00a0\u00a0\u00a0\u00a0\u00a0 discharge [m3<\/sup>\u00a0\u2219\u00a0s-1<\/sup>]<\/p>\n \u00b5p\u03c3<\/sub>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 overfall coefficient [-]<\/p>\n b0<\/sub>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 effective overflow width [m]<\/p>\n g\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 gravitational acceleration [m\u00a0\u2219\u00a0s-2<\/sup>]<\/p>\n h0<\/sub>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 energy head of\u00a0the\u00a0overflow [m]<\/p>\n The\u00a0energy head of\u00a0the\u00a0overflow is calculated using the\u00a0following equation:<\/p>\n where:<\/p>\n h0<\/sub>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 is\u00a0\u00a0\u00a0\u00a0\u00a0 energy head of\u00a0the\u00a0overflow [m]<\/p>\n \u03b1\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 Coriolis coefficient [-]<\/p>\n v\u2080<\/sub>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 inflow velocity [m3<\/sup>\u00a0\u2219\u00a0s-1<\/sup>]<\/p>\n g\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 gravitational acceleration [m\u00a0\u2219\u00a0s-2<\/sup>]<\/p>\n To understand how to read the\u00a0overfall coefficient\u202f\u00b5p\u03c3<\/sub>, it is important to be familiar with the\u00a0parameters used for its determination:<\/p>\n H\u00a0\u00a0\u00a0 is\u00a0\u00a0\u00a0\u00a0 overflow head<\/p>\n H\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 height from crest of\u00a0the\u00a0fixed weir to the\u00a0upstream water level<\/p>\n H\u03c3<\/sub>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 height from crest of\u00a0the\u00a0fixed weir to the\u00a0downstream water level<\/p>\n In\u00a0the\u00a0course of\u00a0investigations on flap gates, a practical question arose regarding the\u00a0similarity of\u00a0the\u00a0hydraulic behaviour of\u00a0a flap gate and a Jambor sill, with the\u00a0focus placed on identifying a flap position that would correspond to this configuration. Based on the\u00a0research of\u00a0Prof. \u010c\u00e1belka on flap gates and V.\u00a0Laco\u00a0[1] on Jambor sills, it was concluded that similar hydraulic behaviour of\u00a0the\u00a0flap gate occurs either when the\u00a0flap is fully lowered or when it is raised by approximately 5\u202fcm above the\u00a0fully lowered position, depending on sill height p (Fig.\u202f9<\/span><\/em>).<\/span><\/p>\n Research on the\u00a0flap gate equipped with additional large baffles and interchangeable small baffles led to the\u00a0identification of\u00a0optimal baffle types for use on real hydraulic structures (Fig.\u202f11<\/span><\/em>), where they help to mitigate flap gate oscillation at low discharges. Optimal baffle shapes are L-profile (type RM.A) and semicircle (type RM.B), with the\u00a0leading edge oriented against the\u00a0direction of\u00a0water flow. On the\u00a0physical model of\u00a0the\u00a0flap gate, the\u00a0baffles were arranged in\u00a0the\u00a0following sequence: 1\u00d7 RM.x, 1\u00d7 RV.A, 2\u00d7 RM.x, 1\u00d7 RV.A, 2\u00d7 RM.x, 1\u00d7 RV.A, 1\u00d7 RM.x. The\u00a0centre-to-centre distance between RM.x baffles was 52\u202fmm, and between RV.A and RM.x baffles it was 60\u202fmm. In\u00a0cases without a combination with RM.x, the\u00a0centre-to-centre distance between RV.A baffles on the\u00a0model was 172\u202fmm. The\u00a0dimensions of\u00a0the\u00a0baffles themselves were adopted from or standardised according to the\u00a0flap gate at Doksany weir. As part of\u00a0the\u00a0observations on the\u00a0model, the\u00a0effective overflow widths at lower discharges were monitored (but not measured). For combinations of\u00a0RV.A and RM.A baffles, individual jets overflowing the\u00a0flap gate were observed. In\u00a0contrast, for combinations of\u00a0RV.A with RM.B, RM.C, or RM.D baffles, unification of\u00a0the\u00a0jets at the\u00a0edges of\u00a0the\u00a0flap gate was observed. In\u00a0the\u00a0case of\u00a0the\u00a0combination of\u00a0RV.A with RM.E or RM.F baffles, the\u00a0jet became unified across the\u00a0entire centre-to-centre distance between the\u00a0RV.A baffles. As a result, no narrowing of\u00a0the\u00a0effective overflow width around the\u00a0RM.E or RM.F baffles was observed\u00a0[7].<\/span><\/p>\n The results for the overfall coefficient under extraordinary conditions (Fig.\u202f7<\/em>) indicate that varying degrees of flooding of the aeration pipe result in an increase in discharge capacity. The graph also reveals a noticeable fluctuation in the results. This fluctuation was caused by the effect of unstable pressures, or rather negative pressures, which must not occur in practice, as they induce vibrations in the structure, leading to its eventual damage. Given that the percentage of flooding of the aeration pipe cannot be directly measured at the hydraulic structure during an extraordinary situation, it is also possible to use such measured and calculated values from models for other applications. However, it is necessary to include the variability of the overfall coefficient values in subsequent calculations.<\/p>\n In\u00a0the\u00a0case of\u00a0the\u00a0overfall coefficient for ordinary conditions (Fig.\u00a08<\/span><\/em>), higher coefficient values can also be observed with greater flap gate inclination combined with a higher degree of\u00a0flooding. This may also be caused by negative pressures, as in\u00a0the\u00a0previous case, despite the\u00a0presence of\u00a0a functioning aeration pipe. However, with increasing overflow head and greater flap gate inclination, the\u00a0values of\u00a0the\u00a0overfall coefficient in\u00a0the\u00a0graph demonstrate the\u00a0effect of\u00a0a functioning aeration pipe, as these coefficient values are noticeably lower than those observed under conditions of\u00a0minimal downstream flooding. Confirmation of\u00a0this hypothesis can be expected following recalculation of\u00a0the\u00a0discharge curves for Kl\u00e1\u0161terec weir by the\u00a0staff of\u00a0the\u00a0state enterprise Povod\u00ed Oh\u0159e, with verification based on the\u00a0water management balance results between the\u00a0profiles upstream and downstream of\u00a0this hydraulic structure.<\/span><\/p>\n In\u00a0connection with the\u00a0above statements and in\u00a0relation to the\u00a0graph showing the\u00a0correlation between the\u00a0flap gate and the\u00a0Jambor sill (Fig.\u202f9<\/span><\/em>), the\u00a0values presented in\u00a0this graph can be confirmed. At the\u00a0same time, the\u00a0graph of\u00a0percentage deviations between the\u00a0flap gate and the\u00a0Jambor sill (Fig.\u202f10<\/span>) clearly <\/span>shows the\u00a0percentage deviation for different values of\u00a0H. This graph confirms the\u00a0similar hydraulic behaviour of\u00a0the\u00a0flap gate even when the\u00a0flap is slightly raised by approximately 5\u202fcm compared to the\u00a0fully lowered position, for various sill heights p. To better understand the\u00a0connection between the\u00a0two graphs (Figs.\u202f9<\/span><\/em> and 10<\/span><\/em>), one can, for example, read from Fig.\u202f9<\/span><\/em> that for a height H\u202f=\u202f2\u202fm (i.e. from the\u00a0crest of\u00a0the\u00a0fixed weir to the\u00a0upstream water level), the\u00a0overflow head h ranges from 0 to 5\u202fcm. With increasing sill height p, both the\u00a0overflow head and the\u00a0percentage deviation increase.<\/span><\/p>\n Based on the\u00a0comparison of\u00a0baffle types, it must be concluded that determining the\u00a0overflow coefficient for various baffle geometries is, in\u00a0fact, irrelevant for practical use. Nevertheless, research into the\u00a0hydraulic behaviour of\u00a0these baffles has made it possible to identify the\u00a0optimal baffle geometry for further applications \u2013 one that fulfils its function without reducing discharge capacity. The\u00a0comparison graph of\u00a0baffle types (Fig.\u202f11<\/span><\/em>) shows a comparison of\u00a0the\u00a0baffles presented in\u00a0the\u00a0illustration of\u00a0baffle types (Fig.\u202f4<\/span><\/em>). The\u00a0graph can be interpreted as indicating how much worse the\u00a0baffle variants shown in\u00a0the\u00a0legend columns perform in\u00a0comparison to the\u00a0respective reference column of\u00a0each baffle. For example, in\u00a0the\u00a0first column representing baffle RV.A, all the\u00a0columns corresponding to combinations of\u00a0RV.A with RM.A through RM.F show negative percentages, as these baffle combinations reduce the\u00a0overall discharge capacity of\u00a0the\u00a0flap gate.<\/span><\/p>\n The\u00a0results of\u00a0the\u00a0research described above provide new insights into various conditions and scenarios encountered on flap gates. By employing physical and mathematical models, it was possible to measure and calculate data that had been missing in\u00a0previous studies, making it now possible to apply these new findings in\u00a0engineering practice. Given that the\u00a0flap gate is the\u00a0most commonly used type of\u00a0gate closure on weirs and dams in\u00a0the\u00a0Czech Republic and Slovakia, this research makes it possible to refine the\u00a0discharge curves in\u00a0existing operating rules and to correct values in\u00a0automated control systems of\u00a0hydraulic structures. This, in\u00a0turn, enhances the\u00a0safety of\u00a0the\u00a0structure and improves water management within\u00a0the\u00a0broader water management system.<\/span><\/p>\n For hydraulic structures equipped with flap gates designed according to J.\u00a0\u010c\u00e1belka\u2019s geometry, i.e. with R<\/span> = 2.25H, equations describing the\u00a0flap motion with introduced eccentricity can be used. This simplifies calculation procedures and eliminates errors associated with reading values from design drawings. This innovative approach offers practical benefits both in\u00a0the\u00a0design phase and in\u00a0subsequent reassessments. At the\u00a0same time, regarding the\u00a0issue of\u00a0flap gate vibrations caused by dynamic water loading, this research enables the\u00a0use of\u00a0a suitable type of\u00a0baffle as a damping element, which extends the\u00a0structure\u2019s lifespan and reduces negative effects during both ordinary and extraordinary situations.<\/span><\/p>\n It is important to say, however, that an unexplored area of\u00a0the\u00a0overfall coefficient graph according to J. \u010c\u00e1belka is the\u00a0interval of\u00a0the\u00a0ratio of\u00a0overflow head to water level height (h\/H) for values less than 0.1. Determining this would require access to a larger physical model than those used so far.<\/span><\/p>\n This paper was written with the support of CTU Prague grant no. SGS25\/084\/OHK1\/2T\/11 \u201cCombined Research of Water Flow on Hydrotechnical Structures.\u201d\u00a0<\/span><\/span><\/em><\/p>\n The\u00a0Czech version of\u00a0this article was peer-reviewed, the\u00a0English version was translated from the\u00a0Czech original by Environmental Translation Ltd.<\/p>\n","protected":false},"excerpt":{"rendered":" This article deals with the hydraulic analysis of a flap gate in Doksany and Strakonice based on the evaluation of experimental measurements performed on a physical and mathematic model at the Water Management Experimental Centre, Faculty of Civil Engineering, CTU in Prague.<\/p>\n","protected":false},"author":8,"featured_media":36029,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[86],"tags":[3892,3893,3891,1669],"coauthors":[695,3864],"class_list":["post-36263","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydraulics-hydrology-and-hydrogeology","tag-baffles","tag-curve-of-overflow-coefficients","tag-flap-gate","tag-hydraulic-model"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/36263","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=36263"}],"version-history":[{"count":4,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/36263\/revisions"}],"predecessor-version":[{"id":36267,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/36263\/revisions\/36267"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/36029"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=36263"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=36263"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=36263"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=36263"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}INTRODUCTION<\/h2>\n
METODOLOGY<\/h2>\n
DATA<\/h2>\n
Doksany hydraulic structure<\/h3>\n
![\"\"](\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2025\/07\/Kralik-obr-1.jpg\")
<\/a>\nFig. 1. Doksany weir<\/h6>\n
Strakonice hydraulic structure<\/h3>\n
<\/a><\/h6>\nFig. 2. Strakonice weir<\/h6>\n
Physical models<\/h3>\n
<\/a>\nFig. 3. Physical model of Doksany weir<\/h6>\n
\n
<\/a><\/h6>\nFig. 4. Types of baffles<\/h6>\n
Mathematical model<\/h3>\n
<\/a>\nFig. 5. Mathematical model of Doksany weir<\/h6>\n
Mathematical model of\u00a0flap gate movement<\/h3>\n
<\/a>\nFig. 6. Diagram of a flap gate<\/h6>\n
RESULTS<\/h2>\n
<\/a>\nFig. 7. Graph of overfall coefficient for extraordinary situations (non-aerated)<\/h6>\n
<\/a><\/h6>\nFig. 8. Graph of overfall coefficient for ordinary situations (aerated)<\/h6>\n
<\/a>\n<\/a>\n<\/a>\nFig. 9. Graph of dependence of a flap gate and Jambor sill<\/h6>\n
DISCUSSION<\/h2>\n
<\/a>\nFig. 10. Graph of percentage deviation of a flap gate and Jambor sill<\/h6>\n
<\/a>\nFig. 11. Graph comparing types of baffles<\/h6>\n
CONCLUSION<\/h2>\n
Acknowledgements<\/h3>\n