长中短叶片复合叶轮离心泵流动数值模拟

基于雷诺时均N-S方程和S-A湍流模型对具有长中短叶片的复合叶轮离心泵内部的流动进行了三维紊流数值计算和分析，获得了过流部件内部的速度场、压力场的分布规律。由于蜗壳和叶轮的联合作用，叶轮通道内流动都是不对称的，除了靠近喉部叶轮通道外，其他两个通道内液流流动的规律和单通道内比较相似，易产生回流的位置也是在长叶片吸力边进口处，靠近长叶片压力边的中部，及靠近吸力边出口处的短叶片通道内；蜗壳对于靠近喉部流道内的流动影响比较大，靠近蜗壳喉部叶轮出口处的相对速度较大，同时在靠近蜗壳喉部的叶轮出口处的通道内较易形成回流区域；叶轮中的静压和总压从进口到出口逐渐增加；从叶轮出口流出的液流在进入蜗壳中时，在蜗壳靠近壁面处有形成旋涡的趋势，蜗壳中的液流螺旋形地向前运动。

Numerical Simulation of Inner Flow in Centrifugal Pump with Long-mid-short Blade Complex Impeller

Based on the Navier-Stokes equations and the Spalart-Allmaras turbulence model, 3-D turbulent flow field in centrifugal pump with long mid short blade complex impeller was calculated and analyzed numerically. The relative velocity and pressure distributions in the flowpart were obtained. It was found that the flow in the channel of the complex impeller was unsymmetrical due to the joint action between the volute and impeller. The flow in other channels was similar to that calculated using the single channel except for the ones near the volute throat. The back flow region was at inlet of long blade suction side, near middle part of long blade pressure side and outlet of short blade suction side. The flow near volute throat was affected greatly by volute. The relative velocity was biggish and it was easy to bring back flow at outlet of the complex impeller near volute throat. And the static and total pressure rose uniformly from inlet to outlet in the impeller. The flow from the impeller outlet to volute had a trend to form the swirl near the wall of the volute and moved forward in spiral direction.