双流道泵叶轮边界涡量流分析与水力优化

Boundary Vorticity Flux Analysis and Hydraulic Optimization of Double-channel Pump Impeller

为优化双流道泵叶轮,对原始泵的内流场进行数值模拟,引入边界涡量动力学理论进行流动诊断,分析了叶轮表面的边界涡量流(BVF)、摩擦力线以及涡量线的分布规律,找到了叶轮内产生不良流动的位置及其动力学根源。根据流动诊断结果,有针对性地调整影响双流道泵叶轮内流状态的结构参数,得到优化后的双流道泵叶轮。联合CFD计算和边界涡量动力学流动诊断方法,对比分析了优化前后的双流道泵叶轮,结果表明:优化后叶轮表面的BVF、摩擦力线以及涡线分布得到明显改善,BVF峰值和均值均显著降低,均匀性指数更接近于1,流动分离被抑制,叶轮受力状况得到改善,扬程和效率等水力性能明显提高。研究结果证明了基于边界涡量动力学理论的流动诊断和优化方法在流道式叶轮机械中应用的可行性。

In order to optimize the double-channel pump impeller,inner flow field of the original pump was simulated and diagnosed by introducing boundary vorticity dynamics theory. Several positive and negative BVF peak areas were observed at different locations of the original impeller,which usually relates to large pressure gratitude and flow separation. By analyzing the distribution of BVF,friction and vorticity lines on the impeller surface,the locations of the bad flow inside the impeller and their dynamic roots were found. According to diagnosis of the flow,the structural parameters affecting inner flow state of the double-channel pump impeller were adjusted to obtain the optimized double-channel pump impeller.Combined with CFD and boundary vorticity dynamics flow diagnosis method,the double-channel pump impellers,before and after optimization,were compared and analyzed. The results showed that the distribution of BVF, friction and vorticity lines on the surface of optimized impellers had been significantly improved. The peak and mean values of BVF were both decreased apparently and the uniform index was much closer to 1. The flow separation was suppressed and force distribution was improved,therefore,the head and efficiency of the pump were improved obviously. The research work proved the feasibility of applying inner flow diagnosis and optimization method based on boundary vorticity dynamics theory in the channel impeller machinery,and it also provided reference for the study of optimization design of other turbomachinery.