The Flow Structure Of The End Down The Ridge-type Flow Plunge Pool Stilling Pool Over Current Role Of The Border

At present, many Hydropower Engineering which are being constructed and plan to be constructed with the characteristics of high water level, large discharge and large power. The dam's energy dissipation becomes especially prominent. Guarantying the flood with huge energy to excrete safely becomes the key technologies in the high dam construction.There is a number of large hydropower projects have special requirements to environment, such as Xiangjiaba hydropower station, can't use trajectory energy dissipation with serious atomization, only to adopt under-flow energy dissipation with less atomization and it is a traditional mode of energy dissipation, the energy can be dissipated through the surface swirl and strong turbulence with energy-efficient, small fluctuations in the tail water, less atomization. But, when under flow energy dissipation applies to large projects with high head and large discharge, hydraulic indicator on the floor and sidewall in the stilling basin is comparatively high, impact protection is very difficult, easily to destroy dissipater, therefore, to solve these problems, The step-down bottom energy dissipater proposed this new form of energy dissipaterThe step-down bottom energy dissipater is a new kind of energy dissipater which can adapt the high water level and large discharge. It has high energy dissipation efficiency and eliminates the atomization influence, comparing with the traditional bottom energy dissipater; the hydraulics targets are greatly decreased in the baffle basin. Presently, the research on step-down bottom energy dissipater has based on the practical engineering and come into use in the engineering at home, but short of basic research results. The thesis is based on the Yunnan Province Fund (2006A0018M). Through changing the inlet energy, inlet angels and step-down heights, the flow pattern, time-average dynamic pressure and velocity are observed in detail. Basing on the test results and using the theoretical analysis, the following research has done:(1) Analysis of the flow patterns in the step-down bottom energy dissipater basin; (2) Research on the Flow patterns influence and effect to the energy dissipater basin; (3) Research on the energy dissipater basin the several of possible destruction and destroy mechanism. The research results are as following:1. The basic movement phenomena and its mechanism of movement which happen during the energy dissipation are introduced; and analyzes on the the energy dissipater basin of flow patterns, research on flow region of the energy dissipater basin in the flow of bottom and the characteristics of the flow patterns.2. Analysis influence and effect of the flo asin.3. Unifying the test, the hydraulic characteristic (including water surface curve, near bottom velocity of flow as well as bottom floor's time-average hydrodynamic pressure) is studied. Studied the energy dissipater basin damage may occur in several types, and analysis its destroy types and mechanism, the effects of different destroy types and the hydraulic characteristics of the energy dissipater basin.w structure under bottom to the energy dissipater b...