基于Star CCM+的闸站上游流道方案设计与数值模拟

为了研究上游流道流态对闸站运行的影响,以一大型闸站为研究对象,基于Star CCM+软件进行了闸站上游流道数值模拟,发现由于流道不对称、过流断面面积变化等原因,在泵站运行模式下进水流道内存在多个较大的旋涡,导致水泵进口速度均匀度分布较差.针对进水流道中的不良流态,对上游流道中有无进口射流扩散角和射流扩散角的大小、流道曲率型线、有无导流栅及导流栅的长度等因素进行了方案设计和水力性能对比分析.研究结果表明:前池较小的流道扩散角可以使流道内旋涡明显改善,当有射流扩散角且扩散角为10°时水泵进口速度偏流角最小,入流最集中;流道型线改为直线段并适当延长可以使流道内流线更加光顺;适当延长导流栅长度可以改善流道前端的死水旋涡区,但导流栅同时会使泵进口条件变差,主流内旋涡扩大.

Design and numerical simulation of upstream flow channel in sluice-pumping station based on Star CCM+

In order to study the influence of flow pattern in an upstream flow channel on the operation of sluice-pumping station,a large sluice-pumping station was used as the research object,and numerical simulations of flow in the upstream channel of the station were carried out based on Star CCM+software.It is found that there are many large vortices in the upstream flow channel in pump station opera-ting mode,resulting in a poor uniformity of velocity in the inlet to the pump due to asymmetry of the channel and change in the cross-sectional area.To remove the unfavorable flow patterns in the inlet flow channel,the upstream flow channel was redesigned by altering channel diffusion angle,channel curvature profile,and flow conditioner length.Their effects on the hydraulic performance of channel were analyzed comparatively.The results show that a smaller flow channel diffusion angle in the pump intake can significantly eliminate the vortex in the flow channel.Specially,when the diffusion angle is 10°,the velocity deviation angle is the smallest and the inflow is the most uniform at the pump inlet.A properly extended straight line channel profile can make the streamlines in the flow channel even smooth.A slightly extended flow conditioner length can suppress the dead water vortex area in front of the flow passage,but the flow conditioner can also worsen the pump inlet flow condition and allow the vortex size in the primary flow to be enlarged.