Evaluation of near-wall solution approaches for large-eddy simulations of flow in a centrifugal pump impeller

Engineering Applications of Computational Fluid Mechanics

卷:10

Zheng-Jun Yang¹  Zhi-Feng Yao²  Fu-Jun Wang² 

[1] CCCC Tianjin Dredging Company Ltd.;

[2] China Agricultural University;

关键词: large-eddy simulation;    near-wall solution;    evaluation;    centrifugal pump impeller;   

DOI  :  10.1080/19942060.2016.1189362

来源: DOAJ

【 摘 要 】

The turbulent flow in a centrifugal pump impeller is bounded by complex surfaces, including blades, a hub and a shroud. The primary challenge of the flow simulation arises from the generation of a boundary layer between the surface of the impeller and the moving fluid. The principal objective is to evaluate the near-wall solution approaches that are typically used to deal with the flow in the boundary layer for the large-eddy simulation (LES) of a centrifugal pump impeller. Three near-wall solution approaches –the wall-function approach, the wall-resolved approach and the hybrid Reynolds averaged Navier–Stoke (RANS) and LES approach – are tested. The simulation results are compared with experimental results conducted through particle imaging velocimetry (PIV) and laser Doppler velocimetry (LDV). It is found that the wall-function approach is more sparing of computational resources, while the other two approaches have the important advantage of providing highly accurate boundary layer flow prediction. The hybrid RANS/LES approach is suitable for predicting steady-flow features, such as time-averaged velocities and hydraulic losses. Despite the fact that the wall-resolved approach is expensive in terms of computing resources, it exhibits a strong ability to capture a small-scale vortex and predict instantaneous velocity in the near-wall region in the impeller. The wall-resolved approach is thus recommended for the transient simulation of flows in centrifugal pump impellers.

【 授权许可】

Unknown