旋转叶轮和叶片扩压器耦合的非定常流动计算

应用STAR-CD流动分析软件和PISO算法,采用滑移网格和多重旋转坐标系技术,全流场计算了旋转叶轮和叶片扩压器耦合的非定常流动.获得了不同时间周期的速度和压力分布,预示了叶轮和叶片扩压器相互干涉的重要流动特征.通过计算发现了以往采用单流道计算所不能发现的流动现象:由于蜗壳的存在,使得每一个流道内的速度和压力分布是非对称的,并随时间的变化而变化.因此,在叶轮机械设计中,要全面和整体地考虑叶轮、扩压器和蜗壳之间的相互关联和耦合及相互间的影响与反影响,不能孤立地分别研究.

Calculation of Unsteady Flow for Interaction between Rotating Impeller and Vaned Diffuser

The unsteady interaction between rotating impeller and vaned diffuser in a whole flow field is numerically investigated with STAR-CD, and PISO algorithmic, sliding mesh and multi-rotating coordinates are employed to solve the governing equations. The unsteady velocity vector and pressure distributions in whole flow field at distinct moment are obtained and important flow character for interaction between rotating impeller and vaned diffuser is predicated, which can not be found if it is just investigated in single flow passage. The simulated results show that the velocity and pressure distributions in each flow passage are nonaxisymmetical and time-varying because volute exists. So, in the fluid machinery design, interaction among rotating impeller, vaned diffuser and volute should be considered completely and integrally. They should not be investigated separately with one isolated from the other.