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Influence of inflow orientation on overflow characteristics over broad-crest
Major, Jakub ; Dušička,, Peter (referee) ; Fošumpaur, Pavel (referee) ; Zachoval, Zbyněk (advisor)
Weirs belong to the basic water structures mainly creating vertical contraction of stream against the flumes, which creating mainly horizontal contraction of stream. In the case of the flow over weir usually occurs change from subcritical flow over critical with critical depth to supercritical flow, therefore overflow. Weirs with rectangular control section are described rectangular longitudinal and transverse profile and horizontal crest. Can be distinguish three basic inflow directions to weir. The first is frontal inflow, which is the most frequent in practice. The second is lateral inflow used in distribution and consumption objects. The third is lower inflow used as laboratory weirs, weirs with deeply submerged wall, etc. In terms of knowledge of influence listed directions of inflows, currently are not sufficiently researched the cases of frontal inflow with side contraction and lower inflow on all types of weirs. Due to extent of the issue, labour is focused only on frontal inflow over broad-crested weir with side contraction and lower inflow over broad-crested weir without side contraction. The goal of the labour was to summarize the current knowledge of the flow over broad-crested weir with side contraction and lower inflow over broad-crested weir without side contraction, describe the character of the flow at the overflow and on the basis of it determine recommendations for measurement and calculation of discharge. Further to define unexplored area, specify methods of solution and verify own measurements. The research dealt with application and optimal numerical model setting for to solve the problem.
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Numerical modelling of flow over auxiliary spillways
Kostelecký, Jiří ; Golík,, Pavel (referee) ; Zachoval, Zbyněk (advisor)
The thesis deals with possibilities of numerical modelling of an overflow over selected types of auxiliary spillways and then the possibilities are verified in particular localities. In thesis, there is carried out the determination of capacity of selected spillways by using several methods: the calculation of the overflow equation, one-dimensional and two-dimensional numerical models and physical model. The author created parametric analysis to each single method. Parametric analysis represent various hydraulic conditions. Subsequently, there is possible to express the effect of parametric analysis. The author makes a comparison of water levels received by mentioned methods set out under the specific hydraulic conditions by calibration of each model with the physical model. Finally, author recommends values of all coefficients which have an impact on results of numerical modelling of the flow over selected types of weirs mostly using like auxiliary spillways.
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Lateral recirculation zones of flow in approach channel of weir
Korálová, Nikola ; Pařílková, Jana (referee) ; Zachoval, Zbyněk (advisor)
The bachelor’s thesis is divided in to the literary research and practical part. The content of the literary research is the issue of side contracted weirs, where occurs side contracted flow. The sudden change of the channel width and formation of upstream wake have direct influence on value of discharge coefficient. There are described types of the weirs, ways of computing discharge and discharge coefficients which are influenced by contraction. In the practical part of thesis is described measurement of the velocity field of side contracted flow by UVP Monitor, follow up by assessment of boundary of the upstream wake, which is situated in the approach channel in front of the weir.
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Submergence of low rectangular sharp-edged broad-crested weirs
Major, Jakub ; PhD, Ján Rumann, (referee) ; Zachoval, Zbyněk (advisor)
This diploma thesis deals with submergence of low rectangular sharp-edged broad-crested weirs. From measurement of water levels in front of and behind of weir at different discharges and different weir heights, were determined values of submergence coefficient depending on relative height of submergence. From these values were determined the equation of submergence coefficient. Measured values were compared which results measurements, which are given in professional literature.
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Influence of inflow orientation on overflow characteristics over broad-crest
Major, Jakub ; Dušička,, Peter (referee) ; Fošumpaur, Pavel (referee) ; Zachoval, Zbyněk (advisor)
Weirs belong to the basic water structures mainly creating vertical contraction of stream against the flumes, which creating mainly horizontal contraction of stream. In the case of the flow over weir usually occurs change from subcritical flow over critical with critical depth to supercritical flow, therefore overflow. Weirs with rectangular control section are described rectangular longitudinal and transverse profile and horizontal crest. Can be distinguish three basic inflow directions to weir. The first is frontal inflow, which is the most frequent in practice. The second is lateral inflow used in distribution and consumption objects. The third is lower inflow used as laboratory weirs, weirs with deeply submerged wall, etc. In terms of knowledge of influence listed directions of inflows, currently are not sufficiently researched the cases of frontal inflow with side contraction and lower inflow on all types of weirs. Due to extent of the issue, labour is focused only on frontal inflow over broad-crested weir with side contraction and lower inflow over broad-crested weir without side contraction. The goal of the labour was to summarize the current knowledge of the flow over broad-crested weir with side contraction and lower inflow over broad-crested weir without side contraction, describe the character of the flow at the overflow and on the basis of it determine recommendations for measurement and calculation of discharge. Further to define unexplored area, specify methods of solution and verify own measurements. The research dealt with application and optimal numerical model setting for to solve the problem.
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Lateral recirculation zones of flow in approach channel of weir
Korálová, Nikola ; Pařílková, Jana (referee) ; Zachoval, Zbyněk (advisor)
The bachelor’s thesis is divided in to the literary research and practical part. The content of the literary research is the issue of side contracted weirs, where occurs side contracted flow. The sudden change of the channel width and formation of upstream wake have direct influence on value of discharge coefficient. There are described types of the weirs, ways of computing discharge and discharge coefficients which are influenced by contraction. In the practical part of thesis is described measurement of the velocity field of side contracted flow by UVP Monitor, follow up by assessment of boundary of the upstream wake, which is situated in the approach channel in front of the weir.
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Numerical modelling of flow over auxiliary spillways
Kostelecký, Jiří ; Golík,, Pavel (referee) ; Zachoval, Zbyněk (advisor)
The thesis deals with possibilities of numerical modelling of an overflow over selected types of auxiliary spillways and then the possibilities are verified in particular localities. In thesis, there is carried out the determination of capacity of selected spillways by using several methods: the calculation of the overflow equation, one-dimensional and two-dimensional numerical models and physical model. The author created parametric analysis to each single method. Parametric analysis represent various hydraulic conditions. Subsequently, there is possible to express the effect of parametric analysis. The author makes a comparison of water levels received by mentioned methods set out under the specific hydraulic conditions by calibration of each model with the physical model. Finally, author recommends values of all coefficients which have an impact on results of numerical modelling of the flow over selected types of weirs mostly using like auxiliary spillways.
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