高水头船闸阀门开启过程水力特性仿真研究

采用动网格技术和VOF方法对高水头船闸阀门开启过程进行非恒定流三维紊流数值模拟,研究阀门段水流急变分离的流态、流速、压力等水力特性参数的时空演化规律,以及出现空蚀与流激振动的危险区域和时刻。研究表明,阀门工作最不利开度是0.4,阀门后狭缝、阀门下底缘及跌坎角处是流噪声源,也是空蚀风险区;开度0.5时突扩体顶板上游侧区域有负压,有空蚀风险;空蚀最危险区域在突扩体升坎反弧末端,最不利工况下,开度0.8时负压高达120.75 kPa。建议进一步对突扩体型进行优化,运行中采用阀门快开方式减小负压持续时间,采取工程措施加强空蚀区的防护。

Simulation Study on Hydraulics Characteristic of High Head Lock during Valve Opening Process Based on Dynamic Mesh Technology

Using dynamic mesh technology and VOF method,the valve opening process of high head lock is simulated successfully by means of k-ε turbulence model.The temporal and spatial changing rule of the hydraulic parameters,such as the flow pattern,the flow velocity and the pressure and the dangerous region and time in which cavitation erosion and flow induced vibration occur is studied.0.4 of valve opening ration is the worst time during the valve opening process,for there are sources of noise at the little gap behind valve,root edge below valve and sharp angle of bank,where the high speed flow and dangerous cavitation erosion also occur.The front part of ceiling has the lowest negative pressure when valve opening ration is about 0.5,which also has the risk of cavitation erosion.When valve opening ration is 0.8,the end of rise step is the most dangerous cavitation erosion region and the pressure is up to negative 120.75 kPa.So the suggestion that the tunnel pattern should be further optimized;the valve should be quicker opened to shorten the duration of negative pressure;and protective measures should be taken to prevent the cavitation erosion is proposed.