{"id":8637,"date":"2020-10-19T10:04:31","date_gmt":"2020-10-19T09:04:31","guid":{"rendered":"https:\/\/www.vtei.cz\/?p=8637"},"modified":"2024-07-17T11:01:32","modified_gmt":"2024-07-17T10:01:32","slug":"vranov-dam-research-of-bottom-outlets-and-crown-spillway","status":"publish","type":"post","link":"https:\/\/www.vtei.cz\/en\/2020\/10\/vranov-dam-research-of-bottom-outlets-and-crown-spillway\/","title":{"rendered":"Vranov dam: research of bottom outlets and crown spillway"},"content":{"rendered":"<h4><i class=\"fa fa-exclamation-circle fa-3x pull-left\"><\/i> This article is available in Czech only. For translation or more information on this topic, please contact author.<\/h4>\n<p>&nbsp;<\/p>\n<h2>Souhrn<\/h2>\n<p>Vodn\u00ed d\u00edlo Vranov bylo dokon\u010deno v\u00a0roce 1934, kde byla na tehdej\u0161\u00ed dobu pou\u017eita inovativn\u00ed technologie koncov\u00fdch uz\u00e1v\u011br\u016f typu Johnson a\u00a0v\u00e1lcov\u00e9 uz\u00e1v\u011bry. Za dobu jejich fungov\u00e1n\u00ed nevy\u017eadovaly v\u011bt\u0161\u00ed opravy, prob\u00edhala pouze b\u011b\u017en\u00e1 \u00fadr\u017eba a\u00a0drobn\u00e9 opravy. Nicm\u00e9n\u011b, sou\u010dasn\u00fd stav uz\u00e1v\u011br\u016f ji\u017e nezaru\u010duje z\u00a0hlediska korozn\u00edho a\u00a0provozn\u00edho po\u0161kozen\u00ed dlouhodob\u00fd spolehliv\u00fd provoz. Povod\u00ed Moravy,\u00a0s. p., si nechalo vypracovat studii rekonstrukce regula\u010dn\u00edch uz\u00e1v\u011br\u016f, v\u00fdsledkem t\u00e9to studie byl n\u00e1vrh v\u00fdm\u011bny \u010dty\u0159 st\u00e1vaj\u00edc\u00edch uz\u00e1v\u011br\u016f za \u010dty\u0159i nov\u00e9 segmentov\u00e9 uz\u00e1v\u011bry. C\u00edlem v\u00fdzkumu bylo ov\u011b\u0159en\u00ed funk\u010dnosti nov\u011b navr\u017een\u00fdch segmentov\u00fdch koncov\u00fdch regula\u010dn\u00edch uz\u00e1v\u011br\u016f spodn\u00edch v\u00fdpust\u00ed VD Vranov a\u00a0d\u00e1le jejich sou\u010dinnost s\u00a0korunov\u00fdm bezpe\u010dnostn\u00edm p\u0159elivem a\u00a0navazuj\u00edc\u00ed kask\u00e1dou. V\u00a0r\u00e1mci v\u00fdzkumu byly postaveny dva fyzik\u00e1ln\u00ed modely\u00a0\u2013 model jedn\u00e9 spodn\u00ed v\u00fdpusti (v\u00a0m\u011b\u0159\u00edtku 1 : 14,68) a\u00a0model hr\u00e1zov\u00e9ho t\u011blesa (v\u00a0m\u011b\u0159\u00edtku 1 : 55). V\u00a0r\u00e1mci v\u00fdzkumu na fyzik\u00e1ln\u00edm modelu spodn\u00ed v\u00fdpusti bylo c\u00edlem zejm\u00e9na stanoven\u00ed kapacity spodn\u00ed v\u00fdpusti ve vztahu k\u00a0hladin\u011b vody v\u00a0n\u00e1dr\u017ei, m\u00ed\u0159e zatopen\u00ed doln\u00ed vodou ve v\u00fdvaru a\u00a0stupni otev\u0159en\u00ed segmentov\u00e9ho uz\u00e1v\u011bru. Model hr\u00e1zov\u00e9ho t\u011blesa slou\u017eil pro posouzen\u00ed prostorov\u00e9ho proud\u011bn\u00ed ve v\u00fdvaru p\u0159i p\u0159ev\u00e1d\u011bn\u00ed vody p\u0159es p\u0159elivn\u00e1 pole, respektive p\u0159i sou\u010dinnosti proud\u016f od spodn\u00edch v\u00fdpust\u00ed a\u00a0p\u0159elivn\u00fdch pol\u00ed. D\u00e1le byla na modelu hr\u00e1zov\u00e9ho t\u011blesa ov\u011b\u0159ov\u00e1na konzum\u010dn\u00ed k\u0159ivka bezpe\u010dnostn\u00edho p\u0159elivu. Nam\u011b\u0159en\u00e1 konzum\u010dn\u00ed k\u0159ivka na fyzik\u00e1ln\u00edm modelu byla n\u00e1sledn\u011b porovn\u00e1na s\u00a0konzum\u010dn\u00ed k\u0159ivkou z\u00edskanou z\u00a0v\u00fdsekov\u00e9ho matematick\u00e9ho modelu. Matematick\u00fd model byl sestaven a\u00a0vypo\u010d\u00edt\u00e1n v\u00a0programu FLOW-3D.<\/p>\n<h2>\u00davod<\/h2>\n<p>Vodn\u00ed d\u00edlo Vranov je tvo\u0159eno p\u0159ehradn\u00ed hr\u00e1z\u00ed le\u017e\u00edc\u00ed nad obc\u00ed Vranov nad Dyj\u00ed a\u00a0n\u00e1dr\u017e\u00ed sahaj\u00edc\u00ed p\u0159i maxim\u00e1ln\u00ed hladin\u011b a\u017e 30 km proti proudu \u0159eky Dyje s\u00a0celkov\u00fdm objemem 132,7 mil. m<sup>3<\/sup>, zatopen\u00e1 plocha n\u00e1dr\u017ee \u010din\u00ed 7,6 km<sup>2<\/sup>. Vodn\u00ed d\u00edlo (d\u00e1le VD) bylo vybudov\u00e1no v\u00a0letech 1930 a\u017e 1934 v\u00a0\u0159. km 175,405 a\u00a0je sou\u010d\u00e1st\u00ed dyjsk\u00e9 vodohospod\u00e1\u0159sk\u00e9 soustavy. Vodn\u00ed d\u00edlo Vranov je v\u00edce\u00fa\u010delov\u00e1 n\u00e1dr\u017e, mezi hlavn\u00ed \u00fa\u010dely VD pat\u0159\u00ed zejm\u00e9na akumulace vody pro zaji\u0161t\u011bn\u00ed minim\u00e1ln\u00edho pr\u016ftoku a\u00a0nadlep\u0161en\u00ed pro odb\u011bry, ochrana p\u0159ed velk\u00fdmi vodami a\u00a0dal\u0161\u00ed vyu\u017eit\u00ed jako nap\u0159. rekreace, rybolov apod. [1].<\/p>\n<h3>Hr\u00e1z vodn\u00edho d\u00edla<\/h3>\n<p>Vzdouvac\u00ed objekt je tvo\u0159en t\u00ed\u017enou betonovou hr\u00e1z\u00ed z\u00a0lit\u00e9ho betonu skl\u00e1daj\u00edc\u00ed se z\u00a019 blok\u016f o\u00a0\u0161\u00ed\u0159ce 13,5 a\u017e 15 m a\u00a0elektr\u00e1rensk\u00e9ho dvojbloku o\u00a0\u0161\u00ed\u0159ce 27 m. D\u00e9lka hr\u00e1ze v\u00a0korun\u011b je 290,5 m, \u0161\u00ed\u0159ka vozovky na korun\u011b hr\u00e1ze je 4,5 m o\u00a0k\u00f3t\u011b 353,39\u00a0m n. m., v\u00fd\u0161ka hr\u00e1ze od z\u00e1kladu \u010din\u00ed t\u00e9m\u011b\u0159 60 m.<\/p>\n<h3>Bezpe\u010dnostn\u00ed p\u0159eliv<\/h3>\n<p>Bezpe\u010dnostn\u00ed p\u0159eliv pro p\u0159ev\u00e1d\u011bn\u00ed povodn\u00ed je vybudov\u00e1n jako korunov\u00fd s\u00a0p\u0159epadem vody p\u0159es betonovou hr\u00e1z. P\u0159eliv je slo\u017een z\u00a0dev\u00edti nehrazen\u00fdch pol\u00ed o\u00a0sv\u011btl\u00e9 \u0161\u00ed\u0159ce 9 \u00d7 13,6 m s\u00a0pevn\u00fdmi prahy na k\u00f3t\u011b 350,10 m n. m. T\u0159i p\u0159epadov\u00e1 pole mezi elektr\u00e1rensk\u00fdm dvojblokem a\u00a0dvojblokem spodn\u00edch v\u00fdpust\u00ed tlum\u00ed p\u0159epadaj\u00edc\u00ed vodu p\u0159\u00edmo ve v\u00fdvaru. P\u011bt z\u00a0\u0161esti pol\u00ed p\u0159il\u00e9haj\u00edc\u00edch k\u00a0lev\u00e9mu b\u0159ehu sv\u00e1d\u00ed p\u0159epadaj\u00edc\u00ed vodu p\u0159es kask\u00e1du v\u00a0lev\u00e9m b\u0159ehu do v\u00fdvaru. \u0160est\u00e9 p\u0159epadov\u00e9 pole tlum\u00ed p\u0159epadaj\u00edc\u00ed vodu p\u0159\u00edmo ve v\u00fdvaru.<\/p>\n<h3>V\u00fdvar<\/h3>\n<p>V\u00fdvar je nepravideln\u00e9ho tvaru o\u00a0pr\u016fm\u011brn\u00e9 d\u00e9lce 58 m, \u0161\u00ed\u0159ce ve dn\u011b 40 m a\u00a0s\u00a0hloubkou pod prahem v\u00fdvaru 4 m. Na dn\u011b v\u00fdvaru jsou um\u00edst\u011bny dva mohutn\u00e9 rozr\u00e1\u017ee\u010de o\u00a0v\u00fd\u0161ce 4,5 m, kter\u00e9 slou\u017e\u00ed k\u00a0tlumen\u00ed energie v\u00fdtokov\u00fdch paprsk\u016f z\u00a0potrub\u00ed spodn\u00edch v\u00fdpust\u00ed. Betonov\u00fd pr\u00e1h na konci v\u00fdvaru je zakon\u010den kamenn\u00fdm z\u00e1hozem.<\/p>\n<h3>Spodn\u00ed v\u00fdpusti<\/h3>\n<p>Spodn\u00ed v\u00fdpusti (d\u00e1le SV) jsou um\u00edst\u011bny v\u00a0lev\u00e9 \u010d\u00e1sti hr\u00e1ze a\u00a0skl\u00e1daj\u00ed se ze \u010dty\u0159 potrub\u00ed DN 1600 s\u00a0osou na k\u00f3t\u011b 307,45 m n. m. V\u00a0dob\u011b sv\u00e9ho dokon\u010den\u00ed byly tyto v\u00fdpusti osazeny koncov\u00fdmi uz\u00e1v\u011bry na svou dobu s\u00a0inovativn\u00ed technologi\u00ed, dva koncov\u00e9 uz\u00e1v\u011bry jsou typu Johnson a\u00a0dva jsou v\u00e1lcov\u00e9. P\u0159ed koncov\u00fdmi uz\u00e1v\u011bry jsou osazeny revizn\u00edmi uz\u00e1v\u011bry\u00a0\u2013 \u0161oupaty a\u00a0na n\u00e1vodn\u00ed stran\u011b jsou spodn\u00ed v\u00fdpusti hrazeny revizn\u00edm spustn\u00fdm stavidlov\u00fdm uz\u00e1v\u011brem typu Stoney.<\/p>\n<h3>Vodn\u00ed elektr\u00e1rna a\u00a0MVE<\/h3>\n<p>Vodn\u00ed elektr\u00e1rna je situov\u00e1na v\u00a0prav\u00e9 \u010d\u00e1sti hr\u00e1ze, ve strojovn\u011b elektr\u00e1rny jsou instalov\u00e1ny t\u0159i Francisovy turb\u00edny, ka\u017ed\u00e1 o\u00a0maxim\u00e1ln\u00ed hltnosti 15 m<sup>3<\/sup>\/s. Mal\u00e1 vodn\u00ed elektr\u00e1rna je situov\u00e1na ve v\u00fdvaru bezpe\u010dnostn\u00edho p\u0159elivu vedle budovy vodn\u00ed elektr\u00e1rny, elekt\u0159inu generuje Francisova turb\u00edna o\u00a0hltnosti 2,4 m<sup>3<\/sup>\/s\u00a0slou\u017e\u00edc\u00ed pro p\u0159ev\u00e1d\u011bn\u00ed minim\u00e1ln\u00edho z\u016fstatkov\u00e9ho pr\u016ftoku.<\/p>\n<h2>Zkouman\u00e1 problematika<\/h2>\n<p>Hlavn\u00ed motivac\u00ed pro rekonstrukci koncov\u00fdch regula\u010dn\u00edch uz\u00e1v\u011br\u016f spodn\u00edch v\u00fdpust\u00ed je zejm\u00e9na jejich sou\u010dasn\u00fd nevyhovuj\u00edc\u00ed technick\u00fd stav. Za dobu jejich fungov\u00e1n\u00ed nevy\u017eadovaly v\u011bt\u0161\u00ed opravy, prob\u00edhala pouze b\u011b\u017en\u00e1 \u00fadr\u017eba a\u00a0drobn\u00e9 opravy. Nicm\u00e9n\u011b, sou\u010dasn\u00fd stav tohoto za\u0159\u00edzen\u00ed jak z\u00a0hlediska korozn\u00edho, tak provozn\u00edho po\u0161kozen\u00ed nezaru\u010duje dlouhodob\u00fd spolehliv\u00fd provoz. C\u00edlem pl\u00e1novan\u00e9 rekonstrukce je dosa\u017een\u00ed obnoven\u00ed pln\u00e9 provozn\u00ed spolehlivosti, v\u010detn\u011b t\u011bsnosti na \u00farovni hodnot pr\u016fsak\u016f spl\u0148uj\u00edc\u00ed sou\u010dasn\u00e9 normov\u00e9 po\u017eadavky a\u00a0prodlou\u017een\u00ed \u017eivotnosti k\u00a0zaji\u0161t\u011bn\u00ed dlouhodob\u00e9 bezpe\u010dnosti cel\u00e9ho VD [2].<\/p>\n<p>V\u00a0prvn\u00edm kroku Povod\u00ed Moravy, s. p., zadalo studii rekonstrukce regula\u010dn\u00edch uz\u00e1v\u011br\u016f firm\u011b Aquatis, z\u00e1v\u011brem studie [2] bylo doporu\u010den\u00ed vym\u011bnit v\u0161echny koncov\u00e9 uz\u00e1v\u011bry za \u010dty\u0159i nov\u00e9 segmentov\u00e9 uz\u00e1v\u011bry.<\/p>\n<p>D\u00e1le bylo zpracov\u00e1no \u201ePosouzen\u00ed hydraulick\u00fdch pom\u011br\u016f v\u00a0prostoru spodn\u00edch v\u00fdpust\u00ed a\u00a0navazuj\u00edc\u00edho v\u00fdvaru VD Vranov\u00a0\u2013 rekonstrukce v\u00fdpust\u00ed\u201c [3], v\u00a0r\u00e1mci t\u00e9to pr\u00e1ce byly v\u00fdpo\u010dtov\u011b ov\u011b\u0159eny p\u0159edpokl\u00e1dan\u00e9 kapacity spodn\u00edch v\u00fdpust\u00ed, proudov\u00e9 pom\u011bry ve v\u00fdvaru a\u00a0posouzeno nebezpe\u010d\u00ed kavitace segmentov\u00fdch uz\u00e1v\u011br\u016f. V\u00a0z\u00e1v\u011bru byly doporu\u010deny zkou\u0161ky, kter\u00e9 by bylo vhodn\u00e9 prov\u00e9st na fyzik\u00e1ln\u00edch modelech VD Vranov.<\/p>\n<p>Navazuj\u00edc\u00ed fyzik\u00e1ln\u00ed v\u00fdzkum byl p\u0159edev\u0161\u00edm zam\u011b\u0159en na:<\/p>\n<ul>\n<li>stanoven\u00ed kapacity spodn\u00edch v\u00fdpust\u00ed ve vztahu k\u00a0hladin\u011b vody v\u00a0n\u00e1dr\u017ei, m\u00ed\u0159e zatopen\u00ed doln\u00ed vodou ve v\u00fdvaru a\u00a0stupni otev\u0159en\u00ed segmentov\u00e9ho uz\u00e1v\u011bru,<\/li>\n<li>n\u00e1vrh konfuzorov\u00e9 \u010d\u00e1sti segmentov\u00e9ho uz\u00e1v\u011bru pro optimalizaci kapacity SV a\u00a0proudov\u00fdch pom\u011br\u016f ve SV a\u00a0v\u00a0navazuj\u00edc\u00edm v\u00fdvaru,<\/li>\n<li>stanoven\u00ed podm\u00ednek pro minimalizaci kavitace p\u0159i manipulaci se segmentov\u00fdmi uz\u00e1v\u011bry,<\/li>\n<li>prostorov\u00e9 proud\u011bn\u00ed ve v\u00fdvaru p\u0159i samotn\u00e9m p\u0159ev\u00e1d\u011bn\u00ed vody p\u0159es p\u0159elivn\u00e1 pole, resp. p\u0159i sou\u010dinnosti proud\u016f od spodn\u00edch v\u00fdpust\u00ed a\u00a0p\u0159elivn\u00fdch pol\u00ed pro nov\u00fd n\u00e1vrhov\u00fd stav, tj. pro osazen\u00e9 segmentov\u00e9 uz\u00e1v\u011bry v\u010d. stavebn\u00ed \u00fapravy strojovny uz\u00e1v\u011br\u016f SV,<\/li>\n<li>bezpe\u010dn\u00e9 p\u0159ev\u00e1d\u011bn\u00ed povod\u0148ov\u00fdch pr\u016ftok\u016f p\u0159es VD s\u00a0nov\u00fdmi koncov\u00fdmi uz\u00e1v\u011bry spodn\u00edch v\u00fdpust\u00ed.<\/li>\n<\/ul>\n<h2>Fyzik\u00e1ln\u00ed modely<\/h2>\n<p>V r\u00e1mci laboratorn\u00edho fyzik\u00e1ln\u00edho v\u00fdzkumu byly postaveny dva modely \u2013 v\u00fdsekov\u00fd model jedn\u00e9 spodn\u00ed v\u00fdpusti v m\u011b\u0159\u00edtku 1 : 14,68 a model hr\u00e1zov\u00e9ho t\u011blesa v m\u011b\u0159\u00edtku 1 : 55.<\/p>\n<h3>V\u00fdsekov\u00fd model spodn\u00ed v\u00fdpusti<\/h3>\n<p>V\u00fdsekov\u00fd model jedn\u00e9 spodn\u00ed v\u00fdpusti zahrnoval kompletn\u00ed potrub\u00ed jedn\u00e9 v\u00fdpusti s\u00a0prostorem\u00a0n\u00e1toku v\u00a0n\u00e1dr\u017ei, n\u00e1tokov\u00fdm kusem, otev\u0159en\u00fdm \u0161oup\u011btem, p\u0159echodov\u00fdm kusem s\u00a0pohybliv\u00fdm segmentov\u00fdm uz\u00e1v\u011brem um\u00edst\u011bn\u00fdm na konci strojovny uz\u00e1v\u011br\u016f a\u00a0kompletn\u00edm v\u00fdvarem zakon\u010den\u00fdm na prahu v\u00fdvaru (viz <em>obr. 1<\/em>). Jednotliv\u00e9 komponenty modelu jako nap\u0159. segmentov\u00fd uz\u00e1v\u011br s\u00a0p\u0159echodov\u00fdm kusem byly vytvo\u0159eny metodou 3D tisku. Voda byla na model p\u0159ivedena p\u0159es Thomson\u016fv p\u0159eliv, kter\u00fd zaji\u0161\u0165oval m\u011b\u0159en\u00ed mal\u00fdch pr\u016ftok\u016f, velk\u00e9 pr\u016ftoky byly m\u011b\u0159eny p\u0159\u00edlo\u017en\u00fdm ultrazvukov\u00fdm pr\u016ftokom\u011brem na potrub\u00ed spodn\u00ed v\u00fdpusti. Limitn\u00edm rozm\u011brem mezn\u00edch podm\u00ednek modelov\u00e1n\u00ed podle Froudova z\u00e1kona mechanick\u00e9 podobnosti byla v\u00fd\u0161ka v\u00fdtokov\u00e9ho otvoru segmentov\u00e9ho uz\u00e1v\u011bru, kter\u00e1 by nem\u011bla b\u00fdt men\u0161\u00ed ne\u017e 60 mm. V\u00a0m\u011b\u0159\u00edtku 1 : 15 je v\u00fd\u0161ka otvoru 64 mm, toto m\u011b\u0159\u00edtko bylo ozna\u010deno jako limitn\u00ed. V\u00fdsledn\u00e9 m\u011b\u0159\u00edtko 1 : 14,68 bylo odvozeno podle skute\u010dn\u00e9ho pr\u016fm\u011bru PE DN110 potrub\u00ed, kter\u00e9 bylo pou\u017eito na fyzik\u00e1ln\u00edm modelu. Fyzik\u00e1ln\u00ed model m\u011bl p\u016fdorysn\u00e9 rozm\u011bry cca 3 \u00d7 10 m a\u00a0v\u00fd\u0161ku 3,5 m.<\/p>\n<p>Extrapolaci v\u00fdsledk\u016f z\u00a0modelu do skute\u010dnosti zt\u011b\u017eoval fakt, \u017ee potrub\u00ed pou\u017eit\u00e9 na fyzik\u00e1ln\u00edm modelu\u00a0\u2013 PE DN110 lze ozna\u010dit jako hydraulicky hladk\u00e9, tj. proud\u011bn\u00ed na modelu se nenach\u00e1zelo v\u00a0kvadratick\u00e9 oblasti odpor\u016f. V\u00a0r\u00e1mci dan\u00e9ho m\u011b\u0159\u00edtka a\u00a0mo\u017enostech hydraulick\u00e9 laborato\u0159e nebylo mo\u017en\u00e9 dos\u00e1hnout p\u0159esn\u00e9 podobnosti ztr\u00e1t t\u0159en\u00edm, proto bylo p\u0159istoupeno k\u00a0jedin\u00e9mu mo\u017en\u00e9mu \u0159e\u0161en\u00ed, kter\u00e9 doporu\u010duj\u00ed Gabriel a\u00a0\u010c\u00e1belka [4]\u00a0\u2013 byly ur\u010deny \u010dty\u0159i n\u00e1vrhov\u00e9 pr\u016ftoky, pro kter\u00e9 byly vypo\u010d\u00edt\u00e1ny hodnoty <em>\u03bb<\/em> ve skute\u010dnosti (pr\u016ftoky odpov\u00eddaj\u00edc\u00ed otev\u0159en\u00ed SV na 100, 75, 50 a\u00a025 %). Proud\u011bn\u00ed se pro tato otev\u0159en\u00ed ve skute\u010dnosti realizuje v\u00a0kvadratick\u00e9 oblasti odpor\u016f, hodnota sou\u010dinitele t\u0159en\u00ed <em>\u03bb<\/em> je cca 0,0138. Hodnota sou\u010dinitele<em> \u03bb<\/em> byla prolo\u017eena vodorovnou p\u0159\u00edmkou v\u00a0Moodyho diagramu, m\u00edsto pr\u016fse\u010d\u00edk\u016f vodorovn\u00e9 p\u0159\u00edmky s\u00a0k\u0159ivkou pro hladk\u00e9 potrub\u00ed odpov\u00edd\u00e1 hodnot\u011b Reynoldsova \u010d\u00edsla, pro kter\u00e9 jsou ztr\u00e1ty t\u0159en\u00edm v\u00a0podobnosti, tato hodnota odpov\u00eddala otev\u0159en\u00ed cca 75 %. Pro v\u011bt\u0161\u00ed otev\u0159en\u00ed byly ztr\u00e1ty t\u0159en\u00edm na modelu m\u00edrn\u011b men\u0161\u00ed ne\u017e ve skute\u010dnosti, pro men\u0161\u00ed otev\u0159en\u00ed byly ztr\u00e1ty m\u00edrn\u011b v\u011bt\u0161\u00ed (relativn\u00ed rozd\u00edly ztr\u00e1t byly v\u00a0rozsahu cca \u00b1 0,5 %). Pro tyto p\u0159\u00edpady byla v\u00a0extrapolaci v\u00fdsledk\u016f fyzik\u00e1ln\u00edho modelu zavedena p\u0159\u00edslu\u0161n\u00e1 korekce celkov\u00e9ho sp\u00e1du [5].<\/p>\n<a href=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-1.jpg\" rel=\"shadowbox[sbpost-8637];player=img;\"><img decoding=\"async\" width=\"800\" height=\"1392\" class=\"alignnone size-full wp-image-8591 lazyload\" data-src=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-1.jpg\" alt=\"\" data-srcset=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-1.jpg 800w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-1-172x300.jpg 172w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-1-589x1024.jpg 589w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-1-768x1336.jpg 768w\" data-sizes=\"(max-width: 800px) 100vw, 800px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 800px; --smush-placeholder-aspect-ratio: 800\/1392;\" \/><\/a>\n<h6>Obr. 1. Rozsah modelu spodn\u00ed v\u00fdpusti a\u00a0fotografie vlastn\u00edho proveden\u00ed modelu spodn\u00ed v\u00fdpusti<br \/>\nFig. 1. Bottom outlet physical model range and actual design<\/h6>\n<h3>Model hr\u00e1zov\u00e9ho t\u011blesa<\/h3>\n<p>Model hr\u00e1zov\u00e9ho t\u011blesa zahrnoval n\u00e1dr\u017e, t\u011bleso hr\u00e1ze s\u00a0dev\u00edti poli bezpe\u010dnostn\u00edho p\u0159elivu, kompletn\u00ed kask\u00e1du, v\u00fdvar, VE, uzav\u00edrateln\u00e9 potrub\u00ed spodn\u00edch v\u00fdpust\u00ed a\u00a0navazuj\u00edc\u00ed koryto pod VD Vranov v\u00a0d\u00e9lce cca 200 m\u00a0\u2013 viz <em>obr.\u00a02<\/em>. Model byl postaven v\u00a0m\u011b\u0159\u00edtku 1 : 55, limitn\u00edm rozm\u011brem byla v\u00fd\u0161ka p\u0159epadov\u00e9ho paprsku proudnicov\u011b zaoblen\u00e9ho p\u0159elivu, kter\u00e1 by m\u011bla b\u00fdt v\u011bt\u0161\u00ed ne\u017e 50\u00a0mm. Voda na model byla d\u00e1vkov\u00e1na pomoc\u00ed Thomsonova m\u011brn\u00e9ho p\u0159elivu z\u00a0rozvodn\u00e9ho syst\u00e9mu laborato\u0159e.<\/p>\n<a href=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-2.jpg\" rel=\"shadowbox[sbpost-8637];player=img;\"><img decoding=\"async\" width=\"800\" height=\"539\" class=\"alignnone size-full wp-image-8593 lazyload\" data-src=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-2.jpg\" alt=\"\" data-srcset=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-2.jpg 800w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-2-300x202.jpg 300w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-2-768x517.jpg 768w\" data-sizes=\"(max-width: 800px) 100vw, 800px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 800px; --smush-placeholder-aspect-ratio: 800\/539;\" \/><\/a>\n<h6>Obr. 2. Model hr\u00e1zov\u00e9ho t\u011blesa<br \/>\nFig. 2. Dam model<\/h6>\n<h2>Fyzik\u00e1ln\u00ed v\u00fdzkum<\/h2>\n<h3>V\u00fdzkum na modelu spodn\u00ed v\u00fdpusti<\/h3>\n<p>V\u00a0prvn\u00ed f\u00e1zi se v\u00fdzkum orientoval na n\u00e1vrh p\u0159echodov\u00e9 \u010d\u00e1sti segmentov\u00e9ho uz\u00e1v\u011bru (p\u0159echod z\u00a0kruhov\u00e9ho pr\u016f\u0159ezu potrub\u00ed na obd\u00e9ln\u00edkov\u00fd v\u00fdtokov\u00fd profil). P\u0159echodov\u00fd kus a\u00a0segmentov\u00fd uz\u00e1v\u011br byly navr\u017eeny podle podkladu \u201e\u010cKD Blansko\u00a0\u2013 Segmentov\u00e9 uz\u00e1v\u011bry\u201c, d\u00e9lka p\u0159echodov\u00e9ho kusu je 2,7 m, p\u0159echodov\u00fd kus se po obou stran\u00e1ch symetricky roz\u0161i\u0159uje pod \u00fahlem 3,4\u00b0 a\u00a0vertik\u00e1ln\u011b je horn\u00ed \u010d\u00e1st konfuzoru ze\u0161ikmena pod \u00fahlem 13,2\u00b0, pr\u016fm\u011br vstupn\u00edho potrub\u00ed je 1,6 m, v\u00fdtokov\u00fd otvor je obd\u00e9ln\u00edkov\u00fd o\u00a0\u0161\u00ed\u0159ce 1,92 m a\u00a0v\u00fd\u0161ce 0,96 m se zaoblen\u00fdmi rohy o\u00a0polom\u011bru 0,16 m. V\u00fdtokov\u00e1 plocha je o\u00a0cca 9 % men\u0161\u00ed ne\u017e vstupn\u00ed kruhov\u00fd profil potrub\u00ed\u00a0\u2013 toto opat\u0159en\u00ed je provedeno z\u00a0d\u016fvodu omezen\u00ed n\u00edzk\u00fdch tlak\u016f v\u00a0potrub\u00ed spodn\u00ed v\u00fdpusti. Takto navr\u017een\u00fd p\u0159echodov\u00fd kus se v\u00a0r\u00e1mci fyzik\u00e1ln\u00edho testov\u00e1n\u00ed osv\u011bd\u010dil a\u00a0byl schv\u00e1len z\u00e1stupci Povod\u00ed Moravy, s. p.<\/p>\n<p>V\u00a0r\u00e1mci pokus\u016f byly posuzov\u00e1ny proudov\u00e9 pom\u011bry v\u00a0potrub\u00ed spodn\u00edch v\u00fdpust\u00ed a\u00a0ve v\u00fdvaru, tvar v\u00fdtokov\u00e9ho paprsku, tlumen\u00ed kinetick\u00e9 energie v\u00fdtokov\u00e9ho paprsku a\u00a0kapacita potrub\u00ed spodn\u00ed v\u00fdpusti. M\u011b\u0159en\u00ed bylo prov\u00e1d\u011bno pro otev\u0159en\u00ed segmentov\u00e9ho uz\u00e1v\u011bru 12,5 a\u017e 100 %, od minim\u00e1ln\u00ed hladiny st\u00e1l\u00e9ho nadr\u017een\u00ed a\u017e po mezn\u00ed bezpe\u010dnou hladinu v\u00a0n\u00e1dr\u017ei a\u00a0od minim\u00e1ln\u00ed hladiny ve v\u00fdvaru po hladinu odpov\u00eddaj\u00edc\u00ed hladin\u011b doln\u00ed vody p\u0159i povodni Q<sub>10\u00a0000<\/sub>. Celkem bylo realizov\u00e1no 138 rozd\u00edln\u00fdch stav\u016f.<\/p>\n<p>V\u00a0r\u00e1mci realizovan\u00fdch pokus\u016f nebylo pozorov\u00e1no nestandardn\u00ed chov\u00e1n\u00ed v\u00fdtokov\u00e9ho paprsku, p\u0159i v\u0161ech stavech byl v\u00fdtokov\u00fd paprsek kompaktn\u00ed a\u00a0byl tlumen v\u00a0prostoru v\u00fdvaru pomoc\u00ed st\u00e1vaj\u00edc\u00edch rozr\u00e1\u017ee\u010d\u016f. Pouze p\u0159i otev\u0159en\u00ed 70 % a\u00a0men\u0161\u00edch otev\u0159en\u00ed segmentov\u00e9ho uz\u00e1v\u011bru byl paprsek sklon\u011bn sm\u011brem dol\u016f a\u00a0nar\u00e1\u017eel do pl\u00e1novan\u00e9ho schodu konstrukce pro provizorn\u00ed hrazen\u00ed, v\u00a0z\u00e1v\u011bru v\u00fdzkumn\u00e9 zpr\u00e1vy bylo doporu\u010deno tento schod ze\u0161ikmit a\u00a0sn\u00ed\u017eit tak, aby nebyl p\u0159\u00edli\u0161 hydrodynamicky nam\u00e1h\u00e1n (v\u00fdtokov\u00fd paprsek dosahoval rychlosti a\u017e 26\u00a0m\/s).<\/p>\n<a href=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-3.jpg\" rel=\"shadowbox[sbpost-8637];player=img;\"><img decoding=\"async\" width=\"800\" height=\"669\" class=\"alignnone size-full wp-image-8595 lazyload\" data-src=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-3.jpg\" alt=\"\" data-srcset=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-3.jpg 800w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-3-300x251.jpg 300w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-3-768x642.jpg 768w\" data-sizes=\"(max-width: 800px) 100vw, 800px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 800px; --smush-placeholder-aspect-ratio: 800\/669;\" \/><\/a>\n<h6>Obr. 3. Z\u00e1vislost v\u00fdtokov\u00e9ho sou\u010dinitele \u03bc<sub>c<\/sub> na velikosti otev\u0159en\u00ed uz\u00e1v\u011bru<br \/>\nFig. 3. Dependence of the flow outlet coefficient \u03bc<sub>c<\/sub> on the size of the radial gate opening<\/h6>\n<p>Z\u00a0nam\u011b\u0159en\u00fdch dat byla vyhodnocena kapacita potrub\u00ed spodn\u00ed v\u00fdpusti a\u00a0z\u00edsk\u00e1na z\u00e1vislost mezi % otev\u0159en\u00ed segmentov\u00e9ho uz\u00e1v\u011bru a\u00a0celkov\u00fdm v\u00fdtokov\u00fdm sou\u010dinitelem spodn\u00ed v\u00fdpusti <em>\u00b5<\/em><sub>c<\/sub>, ve\u00a0kter\u00e9m jsou zahrnuty ve\u0161ker\u00e9 ztr\u00e1ty na v\u00fdpusti\u00a0\u2013 viz <em>obr. 3<\/em> (ztr\u00e1ta na n\u00e1toku, t\u0159en\u00ed, ztr\u00e1ta na otev\u0159en\u00e9m \u0161oup\u011bti, ztr\u00e1ta na p\u0159echodov\u00e9m kusu a\u00a0ztr\u00e1ta na v\u00fdtoku ze segmentov\u00e9ho uz\u00e1v\u011bru). Pomoc\u00ed znalosti tohoto vztahu lze lehce zjistit v\u00fdpo\u010dtem pomoc\u00ed rovnice (1) (rovnice pro v\u00fdtok otvorem) pr\u016ftok spodn\u00ed v\u00fdpusti <em>Q<\/em> na z\u00e1klad\u011b znalosti celkov\u00e9ho sp\u00e1du <em>H<\/em> (rozd\u00edl hladiny v\u00a0n\u00e1dr\u017ei a\u00a0doln\u00ed vody ve v\u00fdvaru, respektive osy potrub\u00ed, pokud je doln\u00ed voda n\u00ed\u017ee), procentu otev\u0159en\u00ed uz\u00e1v\u011bru (respektive v\u00fdtokov\u00e9 plo\u0161e <em>S<\/em><sub>p<\/sub>) a\u00a0gravita\u010dn\u00edmu zrychlen\u00ed <em>g:<\/em><\/p>\n<a href=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-vzorecek-1.jpg\" rel=\"shadowbox[sbpost-8637];player=img;\"><img decoding=\"async\" width=\"800\" height=\"121\" class=\"alignnone size-full wp-image-8601 lazyload\" data-src=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-vzorecek-1.jpg\" alt=\"\" data-srcset=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-vzorecek-1.jpg 800w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-vzorecek-1-300x45.jpg 300w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-vzorecek-1-768x116.jpg 768w\" data-sizes=\"(max-width: 800px) 100vw, 800px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 800px; --smush-placeholder-aspect-ratio: 800\/121;\" \/><\/a>\n<table class=\"no-border\">\n<tbody>\n<tr>\n<td style=\"width: 7.11055%;\">kde<\/td>\n<td style=\"width: 3.89443%;\"><em>g<\/em><\/td>\n<td style=\"width: 7.9146%;\">je<\/td>\n<td style=\"width: 81.0804%;\">gravita\u010dn\u00ed zrychlen\u00ed [m\/s<sup>2<\/sup>],<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 7.11055%;\"><\/td>\n<td style=\"width: 3.89443%;\"><em>H<\/em><\/td>\n<td style=\"width: 7.9146%;\"><\/td>\n<td style=\"width: 81.0804%;\">sp\u00e1d [m],<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 7.11055%;\"><\/td>\n<td style=\"width: 3.89443%;\"><em>Q<\/em><\/td>\n<td style=\"width: 7.9146%;\"><\/td>\n<td style=\"width: 81.0804%;\">pr\u016ftok [m<sup>3<\/sup>\/s],<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 7.11055%;\"><\/td>\n<td style=\"width: 3.89443%;\"><em>S<\/em><\/td>\n<td style=\"width: 7.9146%;\"><\/td>\n<td style=\"width: 81.0804%;\">plocha [m<sup>2<\/sup>],<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 7.11055%;\"><\/td>\n<td style=\"width: 3.89443%;\"><em>\u03bc<\/em><\/td>\n<td style=\"width: 7.9146%;\"><\/td>\n<td style=\"width: 81.0804%;\">sou\u010dinitel p\u0159epadu [-],<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 7.11055%;\"><\/td>\n<td style=\"width: 3.89443%;\"><em>c<\/em><\/td>\n<td style=\"width: 7.9146%;\"><\/td>\n<td style=\"width: 81.0804%;\">celkov\u00fd,<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 7.11055%;\"><\/td>\n<td style=\"width: 3.89443%;\"><em>p<\/em><\/td>\n<td style=\"width: 7.9146%;\"><\/td>\n<td style=\"width: 81.0804%;\">potrub\u00ed.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>V\u00fdzkum na modelu hr\u00e1zov\u00e9ho t\u011blesa<\/h3>\n<p>V\u00fdzkum na modelu hr\u00e1zov\u00e9ho t\u011blesa byl orientov\u00e1n na ov\u011b\u0159en\u00ed kapacity nehrazen\u00e9ho bezpe\u010dnostn\u00edho p\u0159elivu, proud\u011bn\u00ed v\u00a0navazuj\u00edc\u00ed kask\u00e1d\u011b a\u00a0prostorov\u00e9m proud\u011bn\u00ed ve v\u00fdvaru. V\u00a0r\u00e1mci pokus\u016f byla testov\u00e1na p\u0159edsazen\u00e1 konstrukce pro provizorn\u00ed hrazen\u00ed koncov\u00fdch segmentov\u00fdch uz\u00e1v\u011br\u016f um\u00edst\u011bn\u00e1 p\u0159ed strojovnou spodn\u00edch v\u00fdpust\u00ed a\u00a0ze\u010f odkl\u00e1n\u011bj\u00edc\u00ed proud z\u00a0kask\u00e1dy sm\u011b\u0159uj\u00edc\u00ed na d\u011bl\u00edc\u00ed ostrov mezi vodn\u00ed elektr\u00e1rnou a\u00a0strojovnou spodn\u00edch v\u00fdpust\u00ed.<\/p>\n<p>Prostorov\u00e9 proud\u011bn\u00ed v\u00a0kask\u00e1d\u011b a\u00a0v\u00a0navazuj\u00edc\u00edm v\u00fdvaru bylo posuzov\u00e1no pro pr\u016ftoky Q<sub>1<\/sub>\u2013Q<sub>10\u00a0000<\/sub> (1\u00a0374 m<sup>3<\/sup>\/s). V\u00a0sou\u010dasn\u00e9m stavu p\u0159edstavuje nebezpe\u010d\u00ed zejm\u00e9na proud z\u00a0kask\u00e1dy, kter\u00fd m\u00ed\u0159\u00ed kolmo na d\u011bl\u00edc\u00ed ostrov mezi vodn\u00ed elektr\u00e1rnou a\u00a0strojovnou spodn\u00edch v\u00fdpust\u00ed, ostrov je nejv\u00edce ohro\u017een p\u0159i pr\u016ftoku odpov\u00eddaj\u00edc\u00edmu cca Q<sub>50<\/sub>, kdy doln\u00ed voda nen\u00ed p\u0159\u00edli\u0161 vysoko a\u00a0proud z\u00a0kask\u00e1dy m\u00e1 ji\u017e pom\u011brn\u011b velkou kinetickou energii. Toto nebezpe\u010d\u00ed lze odstranit vhodnou kombinac\u00ed provozu spodn\u00edch v\u00fdpust\u00ed, kter\u00e9 odklon\u00ed proud z\u00a0kask\u00e1dy sm\u011brem do v\u00fdvaru mimo d\u011bl\u00edc\u00ed ostrov. Druhou variantou \u0159e\u0161en\u00ed je navrhovan\u00e1 ze\u010f, kter\u00e1 je um\u00edst\u011bna v\u00a0prostoru p\u0159ed strojovnou doln\u00edch v\u00fdpust\u00ed a\u00a0proud z\u00a0kask\u00e1dy odkl\u00e1n\u00ed sm\u011brem do v\u00fdvaru bez nutnosti otev\u00edrat spodn\u00ed v\u00fdpusti.<\/p>\n<p>Dal\u0161\u00ed probl\u00e9m nast\u00e1v\u00e1 od pr\u016ftoku Q<sub>100<\/sub> (435 m<sup>3<\/sup>\/s), p\u0159i tomto pr\u016ftoku je voda p\u0159epadaj\u00edc\u00ed ze t\u0159\u00ed pol\u00ed bezpe\u010dnostn\u00edho p\u0159elivu, um\u00edst\u011bn\u00fdch mezi vodn\u00ed elektr\u00e1rnou a\u00a0strojovnou spodn\u00edch v\u00fdpust\u00ed, tlumena v\u00a0prostoru v\u00fdvaru, kter\u00fd je v\u00a0cca polovin\u011b ukon\u010den d\u011bl\u00edc\u00edm ostrovem mezi v\u00fdvarem a\u00a0v\u00fdtokem z\u00a0vodn\u00ed elektr\u00e1rny. P\u0159i pr\u016ftoku Q<sub>100<\/sub> za\u010d\u00edn\u00e1 voda nar\u00e1\u017eet na d\u011bl\u00edc\u00ed ostrov a\u00a0vznik\u00e1 zde \u201ev\u00fdron\u201c vody sm\u011brem na travnatou \u010d\u00e1st ostrova, voda zde dosahuje rychlosti a\u017e 3 m\/s. \u0158e\u0161en\u00ed tohoto probl\u00e9mu je mo\u017en\u00e9 pouze radik\u00e1ln\u00edm zmen\u0161en\u00edm d\u011bl\u00edc\u00edho ostrova.<\/p>\n<p>Pro n\u00e1vrhov\u00fd pr\u016ftok Q<sub>1\u00a0000 <\/sub>byly zm\u011b\u0159eny v\u00fd\u0161ky p\u0159el\u00e9v\u00e1n\u00ed vody z\u00a0kask\u00e1dy odv\u00e1d\u011bj\u00edc\u00ed vodu z\u00a0krajn\u00edch pol\u00ed bezpe\u010dnostn\u00edho p\u0159elivu pro jej\u00ed p\u0159\u00edpadn\u00e9 nav\u00fd\u0161en\u00ed na n\u00e1vrhov\u00fd pr\u016ftok.<\/p>\n<a href=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-4.jpg\" rel=\"shadowbox[sbpost-8637];player=img;\"><img decoding=\"async\" width=\"800\" height=\"603\" class=\"alignnone size-full wp-image-8597 lazyload\" data-src=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-4.jpg\" alt=\"\" data-srcset=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-4.jpg 800w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-4-300x226.jpg 300w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-4-768x579.jpg 768w\" data-sizes=\"(max-width: 800px) 100vw, 800px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 800px; --smush-placeholder-aspect-ratio: 800\/603;\" \/><\/a>\n<h6>Obr. 4. Konzum\u010dn\u00ed k\u0159ivka bezpe\u010dnostn\u00edho p\u0159elivu<br \/>\nFig. 4. Spillway discharge curve<\/h6>\n<p>Dal\u0161\u00edm c\u00edlem fyzik\u00e1ln\u00edho v\u00fdzkumu bylo ov\u011b\u0159en\u00ed konzum\u010dn\u00ed k\u0159ivky nehrazen\u00e9ho bezpe\u010dnostn\u00edho p\u0159elivu. V\u00a0r\u00e1mci v\u00fdzkumu byly m\u011b\u0159eny stavy od mal\u00fdch povod\u0148ov\u00fdch pr\u016ftok\u016f a\u017e po kontroln\u00ed povode\u0148 Q<sub>10\u00a0000<\/sub>. Probl\u00e9m p\u0159i m\u011b\u0159en\u00ed nastal v\u00a0okam\u017eiku, kdy se hladina v\u00a0n\u00e1dr\u017ei ocitla na \u00farovni spodn\u00ed hrany mostovky, v\u00a0tomto moment\u011b do\u0161lo na p\u0159ilnut\u00ed p\u0159epadov\u00e9ho paprsku na spodn\u00ed stranu mostovky a\u00a0vzniku podtlak\u016f, kter\u00e9 zp\u016fsobily zkreslen\u00ed nam\u011b\u0159en\u00fdch v\u00fdsledk\u016f. Nam\u011b\u0159en\u00e1 konzum\u010dn\u00ed k\u0159ivka zobrazen\u00e1 na <em>obr. 4<\/em> je tedy v\u011brohodn\u00e1 pouze do okam\u017eiku dosa\u017een\u00ed hladiny v\u00a0n\u00e1dr\u017ei na spodn\u00ed \u00farove\u0148 mostovky. V\u00a0tomto p\u0159\u00edpad\u011b bylo rozhodnuto o\u00a0vyu\u017eit\u00ed matematick\u00e9ho modelov\u00e1n\u00ed pro zji\u0161t\u011bn\u00ed kapacity bezpe\u010dnostn\u00edho p\u0159elivu p\u0159i velk\u00fdch povod\u0148ov\u00fdch pr\u016ftoc\u00edch a\u00a0maxim\u00e1ln\u00ed kapacity p\u0159elivu p\u0159i dosa\u017een\u00ed mezn\u00ed bezpe\u010dn\u00e9 hladiny.<\/p>\n<h2>Matematick\u00e9 modelov\u00e1n\u00ed<\/h2>\n<p>Matematick\u00e9 modelov\u00e1n\u00ed bylo pou\u017eito pro zji\u0161t\u011bn\u00ed kapacity bezpe\u010dnostn\u00edho p\u0159elivu pro kontroln\u00ed povode\u0148 Q<sub>10\u00a0000<\/sub>, v\u00fdsledky fyzik\u00e1ln\u00edho modelov\u00e1n\u00ed poslou\u017eily pro kalibraci matematick\u00e9ho modelu. V\u00a0r\u00e1mci matematick\u00e9ho modelov\u00e1n\u00ed byl pou\u017eit CFD (Computional Fluid Dynamics) program FLOW-3D v12.0. Program FLOW-3D vyu\u017e\u00edv\u00e1 vyvinut\u00e9 techniky \u0159e\u0161en\u00ed pohybov\u00fdch rovnic tekutin pro \u0159e\u0161en\u00ed trojrozm\u011brn\u00fdch probl\u00e9m\u016f. Program je mo\u017en\u00e9 vyu\u017e\u00edt pro \u0159e\u0161en\u00ed \u0161irok\u00e9ho rozsahu \u00faloh v\u00a0oblasti proud\u011bn\u00ed tekutin a\u00a0\u0161\u00ed\u0159en\u00ed tepla, \u00falohy jsou \u0159e\u0161eny metodou kone\u010dn\u00fdch objem\u016f za pou\u017eit\u00ed RANS (Reynolds Avaraged Navier-Stokes) rovnic v\u00a0definovan\u00e9 v\u00fdpo\u010detn\u00ed oblasti se specifikovan\u00fdmi okrajov\u00fdmi, respektive po\u010d\u00e1te\u010dn\u00edmi podm\u00ednkami.<\/p>\n<p>Vlastn\u00ed model je tvo\u0159en v\u00fdpo\u010detn\u00ed oblast\u00ed, kter\u00e1 je tvo\u0159ena vz\u00e1jemn\u011b spojen\u00fdmi v\u00fdpo\u010detn\u00edmi bu\u0148kami. Bu\u0148ky rozd\u011bluj\u00ed z\u00e1jmov\u00fd prostor na d\u00edl\u010d\u00ed v\u00fdpo\u010detn\u00ed objemy. V\u00fdpo\u010detn\u00ed bu\u0148ky tvo\u0159\u00ed v\u00fdpo\u010detn\u00ed prostor, kter\u00fd efektivn\u011b parametrizuje re\u00e1ln\u00fd fyzik\u00e1ln\u00ed prostor. Ka\u017ed\u00fd parametr tekutiny je ve v\u00fdpo\u010detn\u00ed s\u00edti charakterizov\u00e1n \u0159adou hodnot v\u00a0bodech v\u00fdpo\u010detn\u00ed s\u00edt\u011b. Skal\u00e1rn\u00ed veli\u010diny jako nap\u0159. teplota a\u00a0tlak jsou definov\u00e1ny ve st\u0159edu v\u00fdpo\u010detn\u00edch bun\u011bk, vektorov\u00e9 veli\u010diny jako nap\u0159. rychlost jsou definov\u00e1ny na st\u011bn\u00e1ch v\u00fdpo\u010detn\u00edch bun\u011bk. Jeliko\u017e se jednotliv\u00e9 fyzik\u00e1ln\u00ed parametry v\u00a0prostoru pr\u016fb\u011b\u017en\u011b m\u011bn\u00ed, jemn\u011bj\u0161\u00ed v\u00fdpo\u010detn\u00ed s\u00ed\u0165 poskytne p\u0159esn\u011bj\u0161\u00ed popis reality ne\u017e hrub\u0161\u00ed v\u00fdpo\u010detn\u00ed s\u00ed\u0165. Jemn\u011bj\u0161\u00ed s\u00ed\u0165 ov\u0161em zvy\u0161uje celkov\u00e9 mno\u017estv\u00ed v\u00fdpo\u010detn\u00edch bun\u011bk, a\u00a0t\u00edm z\u00e1rove\u0148 zvy\u0161uje pot\u0159ebn\u00fd v\u00fdpo\u010detn\u00ed \u010das. Vytvo\u0159en\u00ed v\u00fdpo\u010detn\u00ed m\u0159\u00ed\u017eky je z\u00e1sadn\u00ed krok, kter\u00fd ovliv\u0148uje dobu v\u00fdpo\u010dtu a\u00a0kvalitu z\u00edskan\u00fdch v\u00fdsledk\u016f. V\u00fdpo\u010detn\u00ed s\u00ed\u0165 je tvo\u0159ena strukturovanou v\u00fdpo\u010detn\u00ed s\u00edt\u00ed (kart\u00e9zsk\u00e9 \u010di cylindrick\u00e9 sou\u0159adnice), toto \u0159e\u0161en\u00ed umo\u017e\u0148uje stabiln\u00ed numerick\u00e9 \u0159e\u0161en\u00ed.<\/p>\n<p>Vlastn\u00ed \u0159e\u0161en\u00ed bylo realizov\u00e1no na 2D v\u00fdsekov\u00e9m modelu, kter\u00fd zahrnoval prostor v\u00a0n\u00e1dr\u017ei o\u00a0d\u00e9lce 40 m a\u00a0vlastn\u00ed t\u011bleso p\u0159elivu s\u00a0mostovkou. V\u00fdpo\u010detn\u00ed s\u00ed\u0165 byla tvo\u0159ena bu\u0148kami o\u00a0rozm\u011brech 10 \u00d7 10 cm, v\u00a0bl\u00edzkosti p\u0159elivu byly bu\u0148ky zjemn\u011bny na 5 \u00d7 5 cm. Citlivostn\u00ed anal\u00fdzou byla tato velikost bun\u011bk prohl\u00e1\u0161ena za dostate\u010dnou, men\u0161\u00ed bu\u0148ky poskytovaly stejn\u00e9 v\u00fdsledky, ale v\u00fdpo\u010detn\u00ed \u010das byl n\u00e1sobn\u011b del\u0161\u00ed. Horn\u00ed okrajov\u00e1 podm\u00ednka byla nastavena jako hladina v\u00a0n\u00e1dr\u017ei, doln\u00ed okrajov\u00e1 podm\u00ednka byla ur\u010dena jako v\u00fdtok do volna na konci skluzu bezpe\u010dnostn\u00edho p\u0159elivu v\u00a0dostate\u010dn\u00e9 vzd\u00e1lenosti tak, aby neovlivnila kapacitu p\u0159elivu. V\u00fdsledky matematick\u00e9ho modelu (<em>obr. 5<\/em>) korespondovaly s\u00a0v\u00fdsledky fyzik\u00e1ln\u00edho m\u011b\u0159en\u00ed, nam\u011b\u0159en\u00e9 hodnoty pr\u016ftok\u016f se li\u0161ily maxim\u00e1ln\u011b o\u00a0\u00b1 4 %. Ze z\u00edskan\u00e9 konzum\u010dn\u00ed k\u0159ivky (<em>obr. 4<\/em>) je jasn\u011b patrn\u00e9, \u017ee VD Vranov dok\u00e1\u017ee p\u0159ev\u00e9st kontroln\u00ed povode\u0148 cca 1 m pod mezn\u00ed bezpe\u010dnou hladinou pouze bezpe\u010dnostn\u00edm p\u0159elivem, pou\u017eit\u00edm spodn\u00edch v\u00fdpust\u00ed a\u00a0vodn\u00ed elektr\u00e1rny lze doc\u00edlit ni\u017e\u0161\u00ed hladiny.<\/p>\n<a href=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-5.jpg\" rel=\"shadowbox[sbpost-8637];player=img;\"><img decoding=\"async\" width=\"800\" height=\"507\" class=\"alignnone size-full wp-image-8599 lazyload\" data-src=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-5.jpg\" alt=\"\" data-srcset=\"https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-5.jpg 800w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-5-300x190.jpg 300w, https:\/\/www.vtei.cz\/wp-content\/uploads\/2020\/10\/Hlom-5-768x487.jpg 768w\" data-sizes=\"(max-width: 800px) 100vw, 800px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" style=\"--smush-placeholder-width: 800px; --smush-placeholder-aspect-ratio: 800\/507;\" \/><\/a>\n<h6>Obr. 5. Rychlostn\u00ed pole na v\u00fdsekov\u00e9m modelu (mezn\u00ed bezpe\u010dn\u00e1 hladina)<br \/>\nFig. 5. Velocity field\u00a0\u2013 2D model (maximum water level)<\/h6>\n<h2>Z\u00e1v\u011br<\/h2>\n<p>Fyzik\u00e1ln\u00ed v\u00fdzkum poslou\u017eil jako nenahraditeln\u00e1 sou\u010d\u00e1st v\u00fdznamn\u00e9 rekonstrukce hydrotechnick\u00e9 stavby ve f\u00e1zi projektov\u00e9 p\u0159\u00edpravy. Metoda hydraulick\u00e9ho modelov\u00e1n\u00ed v\u00a0laborato\u0159i je vhodn\u00e1 p\u0159edev\u0161\u00edm pro typy \u00faloh, pro n\u011b\u017e nen\u00ed mo\u017enost hydraulick\u00fdch v\u00fdpo\u010dt\u016f a\u00a0matematick\u00fdch model\u016f na sou\u010dasn\u00e9 \u00farovni pozn\u00e1n\u00ed dostate\u010dn\u011b spolehliv\u00e1. Fyzik\u00e1ln\u00ed model poslou\u017eil zejm\u00e9na p\u0159i posouzen\u00ed proudov\u00fdch pom\u011br\u016f a\u00a0tlumen\u00ed energie v\u00fdtokov\u00e9ho paprsku ve v\u00fdvaru p\u0159i provozu spodn\u00ed v\u00fdpusti a\u00a0k\u00a0p\u0159esn\u00e9mu ur\u010den\u00ed kapacity spodn\u00ed v\u00fdpusti. Prostorov\u00fd model hr\u00e1zov\u00e9ho t\u011blesa umo\u017enil komplexn\u011b posoudit proudov\u00e9 pom\u011bry ve v\u00fdvaru p\u0159i p\u0159ev\u00e1d\u011bn\u00ed povod\u0148ov\u00fdch pr\u016ftok\u016f. Ur\u010den\u00ed kapacity bezpe\u010dnostn\u00edho p\u0159elivu prob\u011bhlo v\u00a0t\u011bsn\u00e9 spolupr\u00e1ci fyzik\u00e1ln\u00edho a\u00a0matematick\u00e9ho modelov\u00e1n\u00ed, kdy v\u00fdsledky fyzik\u00e1ln\u00edho modelu byly pou\u017eity pro kalibraci a\u00a0verifikaci matematick\u00e9ho modelu, na kter\u00e9m byly posl\u00e9ze simulov\u00e1ny stavy, kter\u00e9 nebyly technicky snadno provediteln\u00e9 na fyzik\u00e1ln\u00edm modelu.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Waterwork Vranov was completed in 1934, where at that time innovative technology of Johnson-type and cylinder regulating valves was used. During their operation, they did not require major repairs, only routine maintenance and minor repairs was made.<\/p>\n","protected":false},"author":8,"featured_media":8635,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[86],"tags":[2039,1924,1923,2040],"coauthors":[1635,868],"class_list":["post-8637","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydraulics-hydrology-and-hydrogeology","tag-bottom-outlet","tag-mathematical-modeling","tag-physical-modeling","tag-spillway"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/8637","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=8637"}],"version-history":[{"count":3,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/8637\/revisions"}],"predecessor-version":[{"id":30603,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/posts\/8637\/revisions\/30603"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media\/8635"}],"wp:attachment":[{"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/media?parent=8637"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/categories?post=8637"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/tags?post=8637"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.vtei.cz\/en\/wp-json\/wp\/v2\/coauthors?post=8637"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}