螺旋离心泵的双向流固耦合分析

Bidirectional Fluid Structure Interaction Analysis for the Screw Centrifugal Pump

基于Reynolds时均化N-S方程、标准k-ε两方程湍流模型,以及结构响应的弹性体结构动力学方程,采用多重坐标系法,对螺旋离心泵清水介质时的内流场和结构动力学进行双向流固耦合全三维数值计算,将计算结果与非流固耦合计算流场进行对比,分析流固耦合作用对泵外特性及不同叶轮位置泵内压力场和速度场的影响。结果表明:采用双向流固耦合模式的扬程和效率预测值更接近试验值;在小流量下流固耦合作用对外特性的影响较大,而在大流量下对外特性影响较小;流固耦合作用对压力场和速度场的影响主要集中在蜗壳扩散段,对蜗壳其他部位和叶片影响较小;在两种计算模式下蜗壳中截面压力分布出现明显差别,并在叶片出口正对隔舌时压力分布出现突变。

A full three- dimension bidirectional fluid- structure coupled simulation combined the inner flow field and structure field is established to study the effect of FSI on external characteristics and the pressure field and velocity field at different positions of the impeller in screw centrifugal pump with single blade. For the calculation,the flow field is based on Reynolds- averaging N- S equations and standard two equation k- ε turbulent model with multiple reference frame,and the structure response is based on elastic structural dynamic equation. Compared the results with FSI to that without FSI,the analysis shows that the head and efficiency curve with FSI are much closer to test values,the effect of FSI on external characteristics under low flow rate is larger than that under high flow rate. The effect of FSI on the pressure field and velocity field mainly concentrate in diffuser and less effect on blade and other part of volute. The pressure distribution occurs a significant difference with two calculation methods at the volute middle section,and the pressure distribution produces mutation when the outlet of impeller directly face cutwater.