Mit dem Begriff "Schachtüberfall" wird eine Hochwasserentlastungsanlage bezeichnet, bei der Überschußwasser von einem horizontalen, im Grundriß meist kreisförmigen Überfall in einen senkrechten oder schrägen Schacht geleitet und durch einen Stollen mit geringem Gefälle ins Unterwasser abgeführt wird. Der Fallschacht hat in der Regel Kreisquerschnitt und ist durch einen 90°-Krümmer mit dem Ablaufstollen verbunden. Schachtüberfälle werden in zunehmenden Maße zur Hochwasserentlastung bei Erd- und Steindämmen verwendet. Sie werden getrennt vom Dammbauwerk im Hang oder als freistehende Türme im Becken errichtet. (...):1. Einleitung S. 4 2. Aufgabenstellung S. 7 3. Grundlagen der hydraulischen Berechnung von Schachtüberfällen S. 9 4. Gestaltung und hydraulische Berechnung des Schachteinlaufes S. 16 5. Gestaltung und hydraulische Berechnung des senkrechten Fallschachtes S. 25 6. Gestaltung und hydraulische Berechnung des Krümmers, Ablaufstollens und Tosbeckens S. 101 7. Versuche S. 118 8. Anwendung der Ergebnisse der Arbeit auf dag Beispiel des Schachtüberfalles der Steinbachtalgperre, Westdeutschland S. 148 9. Zusammenfassung und Ausblick S. 157 10. Literaturverzeichnis S. 161 Anlagen

CFD is today a big part of the design process in hydraulic engineering and is more economical and time efficient than traditional scale models. But, there are still issues concerning the agreement with scale models in large and complex geometries. In this degree project a high head, five channeled, slotted flip bucket spillway system is analyzed with the CFD software FLUENT and compared with existing scale model results. The sought hydraulic parameters in each channel were the discharge capacity, the pressure distribution and the throw distance from the flip buckets. The discharge capacity and pressure distribution was practically equal for all five channels and only the throw distance from Channel 1 deviated from the others. The agreement with data from the scale model is quite low. The biggest error sources behind the bad agreement may depend on the lack of computational power which led to bad choice of cell size, model delimitations and simplifications. CFD models can easily be built up by people without experience in hydraulics which can lead to fatal errors when building up the model and interpreting results. Hence, long experience in CFD or verification of the numerical results with several different hydraulic parameters is the only way to guarantee qualitative results from CFD modeling.

Due to the high-speed flow in a chute spillway, cavitation damages often occur. This undesired phenomenon threatens the safety of the structure. For the purpose of eliminating the damages, an aerator is often installed in the spillway. To understand its characteristics, physical model tests are a popular method. To complement the model tests, computation fluid dynamics (CFD) simulations are used to study aerator flows. To represent the two-phase flows, multiphase models should be employed. This thesis examines two of them, namely, the Volume-Of-Fluid model (VOF) and Two-Fluid model. Based on the background of the Bergeforsen dam, the aerator flow is modelled by means of the VOF model. The simulated spillway discharge capacity is in accordance with the experimental data. Compared with the results, empirical formulas fail to evaluate the air supply capacity of aerator as it is wider than the conventional width. A hypothetical vent modification is proposed. For the original and proposed layouts, the study illustrates the difference in the air-flow conditions. The results show that a larger vent area is, for a large-width aerator, preferable in the middle of the chute. To study the flip bucket-shaped aerators in the Gallejaur dam, physical model tests and prototype observations are conducted. The results lead to contradicting conclusions in terms of jet breakup and air entrainment. A CFD model is, as an option, employed to explain the reason of the discrepancy. The numerical results coincide with the prototype observations. The jet breakup and air entrainment are evaluated from air cavity profiles; the air-pressure drops are small in the cavity. The discrepancy is due to overestimation of the surface-tension effect in the physical model tests. Based on the experimental data of an aerator rig at the Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, the Two-Fluid model is used to predict air concentration distributions in the aerated flow. The model includes relevant forces governing the motion of bubbles and considers the effects of air bubble size. The numerical results are conformable to the experiments in the air cavity zone. Downstream of the cavity, the air concentration near the chute bottom is higher, which is presumably caused by the fact that the interfacial forces in the Two-Fluid model are underestimated. / <p>QC 20170224</p>

An elaboration on how to construct a spillway for closure for a large tailings pond completely enclosed by embankments, leading to a situation where construction in bedrock is not possible is presented with the following conclusion. A stepped spillway arrangement constructed with granite blocks will require of large blocks for being stable, and will require of filters that are not always considered functional in long-term perspective. It is presented an analysis of the overall stability of the structure proposed and of the stability of its individual blocks.  In addition, it will be impossible to design a vegetated channel that remains stable, without silting and without erosion, over thousand years without maintenance.

This diploma thesis deals with numerical modeling of water flow. The numerical model was created to simulate the flow of water through the spillway of the Letovice dam. The spillway is constructed as a side channel and is located on the right bank. Autocad 2015 was used to create a 3D model, and FLOW-3D version 11.0.4 was used to create a numerical model.

The diploma thesis is focused on the program development. The program is aimed at finding optimal design parameters for a two-pole emergency spillway. These parameters are the lengths of the spillway edges and their relative height arrangement. The program is based on the flood wave transformation simulation. Multi – gradient algorithm was used for optimization design parameters of a two-pole safety spillway.

Water structure Ivanské jezero was built on the Javorník Creek back between 1905-1907. The main purpose of the dam was accumulation of high volumes of water and protection of the territory downstream. After the adjustment for higher flows on the river Kněžna in Rychnov nad Kněžnou, which was completed in 1937, the water structure lost the protective function. On the basis of an assessment made by Povodí Labe in 1993 - due to the low volume of the reservoir there is no flood wave transformation and already while flow rates greater than Q50 pass through dam, it results in overflowing the dam. To this date water structure Ivanské jezero is in very poor condition due to degradation of the binding material in the dam. The goal of the thesis is to propose a procedure for removal of the existing structure and the subsequent construction of the design and construction of a new – gravity, concrete dam. This work will contain technological removal process of current dam and possible usage options for the dam material. In the next step a new structure will be designed in the place of existing dam. After new design is completed there will be hydraulic assessment of the functional objects, hydrology and stability on the dam.

Master´s thesis aims to design multipurpose reservoirs in the river basin Žlebovský potok in cadastre Vysoké Popovice. The main purpose of the reservoir will be improving the drainage conditions in the basin of the river and revitalization. The reservoir will be designed according ČSN 75 2410 – Malé vodní nádrže. The master´s thesis consists of a text section, hydraulic calculations and graphic attachments.

Thesis develops a simplified design of water management and construction solution in the area of Bezmerov. In the theoretical part basic functional objects are briefly described. Work itself is based on evaluation of landscape morphology from delivered countour lines and geological analysis and following design solution for dry retention water reservoir. For drawing part will be used programs PowerCivil â in which will be created direction solution for body of the dam, flooded area and their cross-sections and horizontal cuts. These will be further processed in program AutoCAD. Retention effects will be reviewed with program HEC-HMS. Design of objects for the water reservoir will be followed with hydrotechnical calculations, drawings and descriptions.

The diploma thesis deals with the design of the water divider near Prostějov on the Romže River. Divider flows will be transferred into the Hloučela River. Within the thesis, hydraulic calculations of the side spillway were solved according to Bürgel, Pavlosky, Engels, Musterle, Kunštátský, Hager and energy solution methods in the Microsoft Excel spreadsheet and by using the HEC-RAS program as well. The calculations were compared to each other. Geometry of the relief water divider on the Romže River and the related buildings was designed based on the performed calculations. The required function of the relief object is guaranteed by manipulation of designed sluice gate. The study includes the text part with the calculations and the drawing part documenting the implementation of the designed measures.