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Current Problems in 2D Numerical Modelling of Water Flow in the River Channels
Grmelová, Eliška ; Skokan, Jiří ; Juriga, Jan ; Chrástová, Veronika ; Pospíšilík, Šimon
Currently, the use of two-dimensional numerical models in modelling water flow in river channels and floodplains is quite common. The quality of hydraulic calculation results is influenced by the number of input parameters. However, crucial in this context is primarily the availability of calibration data. Commonly used data from historical flood records are often burdened with significant uncertainties and, in many cases, are completely lacking. One option to ensure suitable calibration data is to measure flow rates and velocity fields in selected calibration profiles, e.g., using the ADCP method (Acoustic Doppler Current Profiler). The presented article showcases the authors' experiences with the calibration of a 2D numerical model applied to a real location, specifically using the mentioned method. The focus of the calibration lies mainly in the values of Manning’s roughness coefficients and parameters of turbulent models. The conclusion of the article includes a discussion of the results and recommendations for further research directions in the field, which appear promising for practical applications.
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Comparison of 1D and 3D Hydrodynamic Models in Designing a Hydraulic Object of a Dry Reservoir
Skokan, Jiří ; Dráb, Aleš ; Duchan, David
This article describes and compares computational and result differences in 1D and 3D hydrodynamic models, which are used for capacity assessment of flow control structures. The paper focuses on a considered dry retention reservoir located on the Kotojedka stream near the city of Kroměříž, Czech Republic. Based on project documentation, a detailed 1D steady hydrodynamic model using functions of Microsoft Excel and its native VBA language was created for the functional object. The parameters of the functional object were optimized based on the results of the 1D model. During the 1D analysis, some uncertainties occurred which cannot be addressed using standard or even more complex hydraulic analytical methods, such as formation and course of hydraulic jump, manifestation of overflow and bottom inlet submergence and water surface elevation profile in apron. Experimental physical model research was not undertaken in this case due to the high cost of the model relative to its lower significance compared to other, much larger water structures. Therefore a 3D steady hydrodynamic model could bring the required solution in this case and provide the basis for object parameters optimisation. A 3D model was created using Flow – 3D software. The results were compared on a series of QN flow rates from Q10 to Q10000, where QN represents the discharge with a repetition period of once in every N years.
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Fluid couplings and torque convertors
Skokan, Jan ; Jandourek, Pavel (referee) ; Klas, Roman (advisor)
This bachelor thesis is devoted to the issue of fluid couplings and torque convertorsand their combination with mechanical gears. The main section outlines development and design of fluid couplings and torque convertors.Resources to improve their performance are also mentioned. Furthermore, there are mentioned combinations of fluid and mechanical transmission.
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Hydrodynamic model of the Odra river in the locality of Odry
Skokan, Jiří ; Duchan, David (referee) ; Dráb, Aleš (advisor)
The Bachelor's thesis deals with creating 2D hydrodynamic water flow model of Odra river in the locality of Odry (km 85,779 - 93,645). Using a numerical model HEC-RAS 6.2, hydraulic calculations of the peak flows of Q5, Q20, Q100 and Q500 were performed. The outputs were processed in the form of flood hazard maps, threat maps, written profile and drawing documentation.
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Study of flood protection measures in the Kroměříž locality
Skokan, Jiří ; Golík, Pavel (referee) ; Dráb, Aleš (advisor)
The diploma thesis deals with the design and hydraulic assessment of a dry retention reser-voir on the Kotojedka (IDVT 10202906) and Vážanský potok (IDVT 10189772) streams in Kroměříž. The basic designs of the dam parameters and the associated dry retention re-servoir flow control structure were carried out using hydraulic analytical calculations. A 1D hydrodynamic model was built by the author in the HEC-RAS software to assess the flow through this object. In the 1D analysis, some uncertainties could not be resolved, such as the formation and evolution of the hydraulic jump, the effect of the safety spillway and bottom outlet submergence, the capacity of the bottom outlet, the capacity of the apron and the water surface elevation in the apron. It can be assumed that, due to the lower significance of the proposed reservoir, it will not be subjected to research on the phy-sical model. Therefore, a hydraulic analysis with 3D numerical software comes into conside-ration, which in this case can provide results for the hydraulic design or optimisation of the desig-ned object parameters. Using the Flow - 3D hydrodynamic model, hydraulic calculations of water flow through the flow control object were performed. The results were compared with the values determined by the 1D model and analytical calculations. The results were compared in the selected profiles of the dry retention reservoir’s flow control object and the transformation effect of the reservoir.
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Hydrodynamic model of the Odra river in the locality of Odry
Skokan, Jiří ; Duchan, David (referee) ; Dráb, Aleš (advisor)
The Bachelor's thesis deals with creating 2D hydrodynamic water flow model of Odra river in the locality of Odry (km 85,779 - 93,645). Using a numerical model HEC-RAS 6.2, hydraulic calculations of the peak flows of Q5, Q20, Q100 and Q500 were performed. The outputs were processed in the form of flood hazard maps, threat maps, written profile and drawing documentation.
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Fluid couplings and torque convertors
Skokan, Jan ; Jandourek, Pavel (referee) ; Klas, Roman (advisor)
This bachelor thesis is devoted to the issue of fluid couplings and torque convertorsand their combination with mechanical gears. The main section outlines development and design of fluid couplings and torque convertors.Resources to improve their performance are also mentioned. Furthermore, there are mentioned combinations of fluid and mechanical transmission.
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