Optimum Design of a Diffuser Pump for High Efficiency and Favorite Characteristics

通过对扩散泵特性的测量，确定了扩散泵优化设计的目标函数。通过对扩压泵叶片扩压器顶顶通道和机匣壁面的压力测量，阐明了动静相互作用对非定常压力的影响。对泵叶轮的非定常力进行了测量，得到了转子-定子相互作用的主导频率。对包括不稳定流量范围在内的整个流量范围进行了混沌分析，发现李雅普诺夫指数和李雅普诺夫维数是表征泵不满意特性的目标函数。对空化泵特性进行了数值计算，计算得到的空化泵非定常特性与实测值基本吻合。在此基础上，将遗传算法应用于扩散泵叶片扩散器低固体度叶栅的优化设计。遗传算法优化后的低固体度叶栅性能优于原有的叶片扩散器。相反，还没有解决以下问题：(1)全级扩散泵的优化设计；(2)多目标优化设计。

Diffuser pump characteristics were measured to determine the objective functions for the optimum design of the pump. As the results of pressure measurements on bada-to-balde passage in vaned diffuser as well as casing wall of a diffuser pump, the effects of rotor-stator interaction on unsteady pressure was clarified. Unsteady hydraulic forces on pump impeller were measured, and predominant frequencies were found to be attributed by rotor-stator interaction. Chaotic analysis was done for entire flow range including unstable flow range, and Liapunov exponent as well as Liapunov dimension was found to be an objective functions of un favorite characteristics of pump. Numerical calculation was developed for cavitating pump characteristics, and calculated unsteady characteristics of cavitating pump agreed qualitatively with measured ones.Referring to the above results, Genetic Algorithm(GA) was applied to the optimum design of low solidity cascade for the vaned diffuser of a diffuser pump. The low solidity cascade optimized by GA showed better characteristics compared with original vaned diffuser.On the contrary, the following problems have not been solved :(1)Optimum design of diffuser pump for whole stage,(2)Multi objective optimum design.