应用滑移网格技术分析多级离心泵的三维瞬态流动

3-D Analysis for Transient Flow in a Multistage Centrifugal Pump Using Sliding Mesh

运用滑移网格技术、三维非稳态Navier-Stokes方程和标准的k-e湍流模型对工业中常用的D型多级节段式离心泵进行了全三维瞬态流场的数值模拟,分析泵内叶轮与导叶间的动静干扰问题。滑移网格设置在多级离心泵叶轮出口与固定导叶入口之间的交互界面,对每个时间步求解流动方程。对任一个叶轮旋转周期内,分析叶轮径向力、静压等参数出现脉动信号频率与动、静叶片数的关系;分析静、动叶片间静压值沿周向的变化规律。该三维非稳态模拟结果可为多级离心泵的水力优化设计提供依据。

By means of sliding mesh technique, a 3-D unsteady numerical simulation is carried out within an entire stage of a multistage diffuser pump in this work. Unsteady Reynolds-averaged Navier-Stokes （RANS） equations with standard k-e turbulence models are solved in the pump stage to investigate transient flow field and pressure fluctuations due to the interaction between impeller and diffuser vanes. The sliding grid interface is set with a ring zone between impeller outlet and diffuser vane inlet. Sliding mesh calculation is performed as the impeller zones slide （i. e. , rotate） relative to diffuser zone along the grid interface in discrete time steps. The complicated time-periodic and spatial-periodie characteristies as well as rotor-stator interaction phenomena inside the pump stage are simulated and analyzed to understand dynamic variation of the interior flow field and interference and finally to aim at optimal design.