大型泵站进水流场十字消涡板整流特性研究

为研究十字消涡板对喇叭管下方水体及进入喇叭管内部水体的整流效果，以一大型泵站为研究对象，采用CFD计算方法进行了泵站流场数值模拟。研究发现，不设置消涡装置时，进水池存在大尺度回流和旋涡，并且在喇叭管正下方存在高速度及高涡量区，从而导致水泵进口流态恶化。在设置了高宽比分别为6:8，6:15和6:24的三种十字消涡板后，进水池流场、吸水喇叭口入口断面及水泵进口断面的流速均匀性均有显著变化。相对于高宽比为6:8和6:24的方案，高宽比为6:15的方案能明显减小进水流场底面上高速区，流场变得更加均匀，使得吸水喇叭管中轴线纵剖面上的涡量分布特征值由不设置消涡装置时的0.508减小到0.101，喇叭管入口断面的涡量分布特征值由0.495减小至0.098，喇叭口入口断面的流速均匀度最大提高4.1%，水泵进口断面的均匀度最大提高3.2%。研究结果对大型泵站进水池流态控制有一定指导意义。

Cross vortex baffles for rectification of flows in intake field of a large-scale pumping station

This paper reports an investigation on the effect of cross-shaped vortex baffles in rectifying the flows in the forebay and intake pipes at a large-scale pumping station using CFD simulations. Results show that without anti-vortice devices, large-scale circulations and vortices are observed in the forebay, and that zones of high velocity and high vorticity exist around the pump inlets, leading to adverse flow patterns. But dramatic changes occur in flow uniformity in the forebay and at the bell mouth inlets and pump inlets when cross vortex baffles are installed. Three depth-width ratios of 6:8, 6:15 and 6:24 of the baffles are examined and compared, and it is found that the ratio of 6:15 is the best in terms of flow uniformity and high-velocity zone suppressing. This anti-vortice scheme can remarkably reduce vorticity from the typical no-baffle value of 0.508 to 0.101 at the pipe centerplanes and from 0.495 to 0.098 at the bell mouth inlets. Also, it can increase the uniformity of axial velocity by 4.1% at the bell mouth inlets and 3.2% at the pump inlets. Thus, the cross-shaped vortex baffle is a useful device for rectification of the flows in the intake field of the large-scale pump station.