Hom Deep Into The Pool Angle On The Hydraulic Characteristics Of Energy Dissipation In The End Down The Ridge Type

In the 1970s and 1980s, how to increase the efficiency of energy dissipater is an important studying topic in the energy discharging engineering with low and middle water level. The traditional energy dissipating ways are: bottom energy dissipater, energy dissipater by hydraulic jump, surface flow energy dissipater. Basing on the traditional dissipater, many new energy dissipaters are adopted in the practical engineering. Much fruits were gained about how to increase the efficiency of energy dissipater, the efficiency of energy dissipater is great improved.With the development of water conservancy and the establishment of west development stratagem, many high water level, large flow engineering are built. The damage of high velocity flow to the building itself is more and more paid attention. The reason of the bottom's structure damage because of the water's pulsatile is the water's high velocity to the bottom of baffle basin. The key research topic of the "10.5"and "11.5" Technique Break is not how to increase the efficiency of energy dissipater but how to low the damage to the construction. How to solve the high hydraulic targets that appear in the traditional energy dissipater is the study emphases of high university and scientific research offices.The step-down energy dissipater basing on the energy dissipation by hydraulic jump is a new energy dissipater which aims to solve the problems that appear in the traditional energy dissipater. It is formed through the optimization to the traditional energy dissipater by hydraulic jump. Low the bottom's elevation comparatively to the elevation of baffle basin's inlet. The step-down energy dissipater basing on the energy dissipation by hydraulic jump is used in the Jin An Qiao station san the Xiang Jia Ba station in China. The results of model test of the Xiang Jia Ba station show that this kind of dissipater can effectively low the hydraulic guidelines such as the high flow velocity near to the floor and the pulsating pressure and avoid the fogy phenomena. The result of energy dissipation is well. Because of the existence of step-down, the flow pattern of baffle basin is changed from the wall jet to the submerged bottom flow pattern. The distribution of turbulent energy in the baffle basin is also changed and the velocity is lowed when the main water flow, decrease the crush to the bottom and it is propitious to the bottom's protection.The thesis is based on the province fund (2006A0018M).Through the hydraulic test, studying the influence of the change of step-down heights and inlet angels to the hydraulic guide lines. Through the analysis of test data, the change rules of hydraulic guide lines in the baffle basin are got. Through the analysis of flow, the mathematic model about the velocity in the middle line of main flow is set up. Through the contrast of theory results and the test results, validating the correctness of the mathematic model and providing reference to the design of baffle basin.