Study On Hydraulic Characteristics Of Full - Area Aeration And Erosion - Reducing Facilities In Steep Slope Open Channel

The rapid development of economic and society needs in energy as material foundation, hydropower resources is the most mature development technology and development of the largest clean energy. China is rich in hydropower resources, and the development and utilization of the water resources has much potential. With the progress of science and technology, especially the damming technology improves, he construction of high dam engineering has been increased more and more, mean while high-speed flow caused by cavitation damage is also growing. By setting aerator facilities to reduce the cavitation damage is the most economic also the simplest method, through forced aeration making the water to maintain a certain air concentration so as to achieve the purpose of reducing erosion.In this paper, through steep channel hydraulics model test, using the research method of control variables by changing the aeration facilities’ type and size, flow to get different test conditions. Under different conditions, air concentration, cavity length, length of protective segment, flow velocity are studied.There are five chapters in this paper. The first chapter focuses on the concept of cavitation, the mechanism of cavitation damage, the measures of reduction cavitation,type of aerated flow, the cause of the flow aeration, the type of aeration corrosion reduction facilities basic shape.In second chapter, air concentration, the bottom of the cavity length, length of protective segment, cavity backwater are studied base on setting bottom aeration facilities. Characteristics of aerated flow is researched in the third chapter on the basis set of lateral aerator. The fourth chapter mainly compared joint aerator with bottom aerator and lateral aerator. The fifth chapter describes the research results and conclusions obtained in this experimental study.Through theoretical analysis and experimental study, obtained the following findings and conclusions. The air concentration of three kinds of aeration facilities distribution law is basically the same, namely air concentration increased gradually at first, and then declined gradually and close to a stable value. In the experimental range,air concentration decreases with the increase in flow; air concentration of aeration facilities slope ratio and height positively correlated.In the test range, the cavity length is increased with the flow rate decreases, with increasing aerator slope ratio increases. "When the bottom cavity and the lateral cavity exist at the same time, they influence each other.When the ramp height is constant, length of protective segment decreases as the flow rate increases, as the flip bucket slope ratio decreases. Combined aeration effective length of protective segment should be greater than the single aeration facilities.The research results can provide experimental basis for optimizing the aerated facility type, arrangement way of aeration.