中文摘要：

针对叶轮机械传统优化设计周期长、优化效率低等不足,提出了一种基于代理模型的优化设计方法,并应用于串列泵的优化设计,分析了关键设计参数对串列泵性能的影响。选择首、次级叶轮叶片安放角和相位角作为优化参数,选择效率和最小轴向截面平均压力系数作为优化设计目标函数,用来表示串列泵的外特性和空化特性。采用不同的方法建立代理模型,并采用敏感度分析方法和Pareto front方法进行参数影响分析和最优点的选取。采用数值计算的方法对优化后的串列泵外特性和空化特性进行验证,得到结论如下：提出的方法可以较好地应用于串列泵的优化设计,优化结果表明串列泵设计流量附近的效率和空化性能均得到提升。首、次级叶轮相位角对串列泵性能影响较小;首、次级叶轮叶片安放角对串列泵效率的敏感度之比和设计的载荷之比相同,首级叶轮叶片安放角是串列泵的空化特性的主要影响因素。

英文摘要：

In this paper,we propose a global design optimization method based on a surrogate model for an axial-flow tandem pump,in order to overcome the disadvantages of conventional optimization methods,including their long design period and lower efficiency. We discuss the influences of the primary design parameters on pump performances,and used fixed blade angles in both the front and rear impellers,as well as the phase angle,as design variables. We selected efficiency and the minimum average pressure coefficient on the axial sectional surface as the objective functions,which represent the energy and cavitation performances,respectively. Surrogate models were constructed based on various methods. In addition,we used global sensitivity analysis and Pareto front methods to further analyze the design parameters and optimum point. The results show that the optimization results can enhance tradeoff performances well,with respect to both efficiency and cavitation performance,in the vicinity of the design flow of the tandem pump. The influence of phase angle on performance can be neglected relative to the influence of the other two design variables. The impact ratio on efficiency of a fixed blade angle in the two impellers is the same as in their designed loading distributions. A fixed blade angle in the front impeller has a great influence on cavitation performance.