Abstract:Reasonable selection of energy dissipation type of spillway building structure is an important issue related to the safety and economy of the whole water conservancy project. The hydraulic calculation of energy dissipation mode is carried out by spillway design code, and the hydraulic characteristics of traditional underflow energy dissipation and sill type underflow energy dissipation are compared and analyzed by combining with physical model test. The results show that when the traditional underflow energy dissipater checks the discharge of flood, the flow of underflow energy dissipater will produce a certain degree of far drive hydraulic jump after it enters the stilling basin. The energy dissipation of stilling basin is mainly located in the back of stilling basin. The backwater of the back and outlet of stilling basin is high and fluctuates violently. There is no relatively stable energy dissipation water body. The energy dissipation effect of the stilling basin is not very good, so the length of the stilling basin needs to be increased. The floor elevation of the plunge sill type underflow stilling basin is reduced by 1 m, but the flow velocity near the bottom is significantly lower than that of the underflow stilling basin. The flow in the stilling basin is fully diffused and the shear is obvious. The stable water body is formed in the back section of the stilling basin, and the energy dissipation effect is good. The flow pattern in the outlet channel is improved, and it is not easy to scour and destroy the stilling basin. The increase of cavitation number of the bottom flow energy dissipation of the falling still type is relatively not easy to cause cavitation, which may avoid the cavitation damage of stilling basin. The maximum hydraulic jump position moves forward 7 m, the water flow will not impact the bottom plate and tail sill, and the water flow will splash vertically. Therefore, the flow pattern in the stilling basin is stable, the inference of atomization is small, and it has the advantages of strong adaptability, high energy dissipation efficiency and stable flow pattern.
洪振国*,苟勤章,李海华. 水利工程溢洪道底流消能水力特性分析[J]. 排灌机械工程学报, 2022, 40(3): 258-263.
HONG Zhenguo*,GOU Qinzhang,LI Haihua. Analysis of hydraulic characteristics of spillway underflow energy dissipation in hydraulic engineering. Journal of Drainage and Irrigation Machinery Engin, 2022, 40(3): 258-263.