汽车冷却水泵优化设计及试验研究

针对比转数为59的汽车冷却水泵,选择对性能影响较大的叶轮的6个水力参数β2,b2,D2,Z,D0,φ,并添加了1个附加的辅助因素e.根据叶轮原有参数值,设计2组不同的参数值,得到因素的2个水平.由此,设计了L8(2⁷)七因素两水平的正交表,即8个叶轮设计方案.通过Ansys-CFX12.1软件分别对8个方案水泵的全流场进行定常数值模拟,以设计工况点的扬程和效率以及最高效率点的流量、扬程和效率为性能指标,通过极差分析以及内部流场对比分析,优化叶轮参数.将优化后的叶轮和原始叶轮分别进行数值模拟和外特性试验,分别比较得到的结果后得出,优化叶轮提高了水泵在额定点的效率,并且增大了高效区范围,同时也使扬程曲线更平缓.结果表明了正交法的可行性,说明了正交表结合CFD技术进行水泵设计,不仅可有效改善水泵产品的水力性能,并且能很大程度地缩短研究时间,从而提高工作的效率.

Optimization design and test study on automobile cooling pumps

Six impeller hydraulic parameters with obvious effects on the performance,β2, b2, D2, Z, D0 and φ were analyzed for an automobile cooling pump with specific speed ns=59, and an auxiliary factor e was also considered. According to the original values, two sets of parameters were designed, and two levels were chosen. According to the orthogonal table L8(27)designed, eight design schemes of impeller were obtained. Steady simulations of the flow in the pump was carried out by Ansys-CFX12.1. Taking head and efficiency at design point as performance target as well as flow rate, head and efficiency at best efficiency point, based on range analysis and comparative analysis of inner flow, the impeller parameters were optimized. The calculated and experimental performance results have been obtained for both the optimized and the original impellers. The results show that the optimized impeller improves the hydraulic efficiency of the pump, and the high efficiency range is widen when more flat head curve can be obtained. The discussion shows that orthogonal method on the pump design is feasible and the numerical simulation is reliable. The combined design method will improve pump performance conveniently, and testing pump performance on the basis will shorten development period and improve work efficiency. 