在节点数基本相同的条件下,对一台离心泵分别划分结构网格、非结构网格和混合网格,采用RNG κ-ε湍流模型,对三种类型的网格进行三维定常全流场数值模拟.基于结果进行性能预测以及内流特征分析,并与PIV实验结果进行对比.结果表明:对外特性而言,结构网格的计算精度最高,而混合网格的计算精度略高于非结构网格;三类网格叶轮出口处w/u值从压力面到吸力面的变化趋势与实验值一致,但结构网格和混合网格的计算结果更接近实验值;三类网格流线分布相似,但结构网格和混合网格能够捕捉到更多的漩涡;在相同节点数的情况下,结构网格和混合网格的计算效率较非结构网格要高.
The chief objective of this study is to verify the effects of different types of grids on numerical calculation accuracy of centrifugal pumps. Unstructured grids, structured ones and hybrid ones with almost the same number of nodes were meshed on computational domain and the three grids were simulated in the design conditions hy the RNG κ-ε turbulence model. From the calculation results, the performance was predicted and the internal flow field was analyzed. The predicted performance and the flow field were compared with personal identity verification (PIV) experiment results. The results indicated that structured and hybrid grids show their hetter calculation results on pump performance and higher calculation efficiency than that of the unstructured grid. By companion of unstructured grids, the value ω/μ based on structured and hybrid grids are closer to the PIV experimental results. The flow fields are qualitatively similar in the three models. More vortices are present in structured and hybrid grids than in unstructured grids. The efficiency is higher in the structured and hybrid grids than in the structured grids under the same numbers of nodes.