The Sudden Expansion Of The Hydraulic Characteristics Of The End Down The Ridge-type Energy Dissipator

With the western development strategy and the implementation of the western region to speed up economic development and will activate abundant hydropower resources and promote the implementation of water resources in the western region. With the deepening of hydropower development, many large-scale hydropower project started or are about to build. Most of these projects have the characteristics of high head and large discharge and its energy dissipation is the key to technical problems, for a long time, design departments, colleges and universities, scientific research departments attach great importance to it.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, a great deal of research was carried on by our predecessors and yielded fruitful results.Paper summarizes the results of previous studies and problems, in view of existing problems, we put forward a new kind of energy dissipation that energy dissipation by hydraulic jump with sudden expansion and abrupt drop in the bed, compared to conventional energy dissipater, it effectively reduces the hydraulic indicators on the floor and sidewall, increases the stability of dissipater its own and at the same time flow stability in the stilling basin, higher energy efficiency and so on, due to existing sudden expansion and abrupt drop in the bed, turbulent flow becomes more stronger in the stilling pool, there are varying degrees of horizontal and vertical whirls. As the new type of energy dissipation in the form of significant practical significance of practice, while at home and abroad, there is no example of engineering application, with the addition of the whole society to strengthen the awareness of environmental protection, the States pays constant attention to environmental protection, the environment-friendly forms of energy dissipation promote the use of a more significant social benefits.Through a combination of methods of theoretical analysis and hydraulic test, energy dissipation mechanism of energy dissipation by hydraulic jump, velocity distribution and its mechanism of reducing velocity on floor and sidewall, pressure distribution, the main factors of affecting hydraulic indicators and so on are analyzed by theoretical, and yields some theoretical results. Hydraulic test is adopted to analyzed the hydraulic indicators in the stilling basin, and verifying the theoretical results, focused on analysis of hydraulic indicator of vertical whirl in the backflow zone, and comes to put forward the relation of the velocity on the sidewall and average-velocity of intake flow, it is verified by hydraulic test.