Experiment And Optimize Run For The Level Spiraling Flow Spillway Tunnel Of Gongboxia

The level spiraling flow has the advantage of high energy dissipation, simple construction and flexible disposal, which as the new pattern. In order to make this technique get expansion and application, the dissertation first sums up the experiment and research of four kinds of spiraling flow spillway tunnel in Gongboxia, and then through a model experiment contrasts hydraulic character of the last design bodily form at different work condition, optimized the run, combines prototype observation design to measure the model data, and passes the theories analysis tallies up empirical formulas.Through experiment enunciated, the strobe 1/4 open degree can not satisfy the discharge, besides which, the other three kinds of open degree can satisfy. Through trial data also analyses the relation between discharge capacity and water head on weir to drowned flow, it is the linearity relation at the former three kinds of open degree, and is secondary polynomials at strobe 1/4 open degree. Flow condition is drowned flow and more stable when the water level above 2002.0m at strobe full open, it is better at strobe 3/4 open, is more stable when water level above 2005.0m at 1/2 open, and condition always unsteady at 1/4 open.Suction appears on the bottom of weir along with lower water level, suction in the level hole mainly concentrated in three variety segments, the back of plunge pool gradually change, the pinch frusta extending part, and escape tunnel mutation segment has suction at anytime, so should adopt appropriate measure to prevent cavitation pitting breakage.The relation curve direction between aeration quantity and water level of upper five blowholes is basic same, it sometimes inhales and sometimes blows at strobe full and 1/4 open, there is not air to pass in and out at strobe 3/4 open, water level for 1/2 open degree the more lower the aeration quantity is more big. The lower blowhole always has gas pass and inhales in whole experiment, but each strobe open degree the relation curve is totally different, the overall aeration quantity mutative curve upper and lower is the same direction and the lower aeration quantity curve, just number is dissimilar.Flow spiraling angle minish at strobe full and 1/4 open degree can reflect energy dissipation rate following the distance on the side, But it can not reflect at strobe 3/4 and 1/2 open degree. Get conclusion through an on trial data, the Gongboxia level spiraling flow spillway tunnel energy dissipation rate looks like the constant.Through the comprehensive analysis to hydraulic character, makes certain excellent run of level spiraling flow: Want to promise firstly the spillway tunnel flow condition is drowned flow in any time, secondly avoid small open degree or low water level to circulate.