Research on the Selection and Optimization of Horizontal Swirling Energy Dissipation Flood Discharge Tunnel

Abstract

Through the study of the diameter control of the horizontal swirling efficiency shaft and the swirling tunnel and the cross-section of the aeration sill, a flood discharge tunnel with a scale of about 100 meters and a discharge volume of more than a thousand is obtained. The horizontal swirling energy dissipation type is combined with the diversion tunnel. At the time, the diameter of the shaft can be controlled and determined according to the average velocity of 15-20m/s; the diameter of the swirling hole can be calculated according to the empirical formula D=(Q2/g)0.2. In order to reduce the impact of water flow pulsation on the concrete lining and surrounding rock of the shaft, the flood discharge tunnel inlet should adopt a submerged flow pattern. Its discharge capacity will be controlled by the cross section (A) of the aeration sill in the shaft and the inlet section (σ) of the swirl chamber. When the slope of the aeration sill is 1:2.5 to 1:3.0, σ/A should be controlled at 1.05. The research results can provide a reliable basis for the design of horizontal swirling energy dissipation.