为满足轴流泵叶片的水力和结构性能,对轴流泵叶片采用基于i S I G H T的多学科设计优化。在确立叶栅稠密度及其沿展向变化规律、轮毂比和厚度比作为设计变量的基础上,建立了轴流泵叶片多学科协同优化模型,提出了协同优化算法在轴流泵叶片多学科设计优化过程中的改进方法,系统级采用约束松弛法,子系统级采用响应面法。经实例运行,证实了基于约束松弛的协同优化算法能够很好地解决轴流泵泵叶片设计中2个学科的耦合以及数据量大和数据关系复杂的问题。同时约束松弛法的引入又使得协同优化的计算收敛更快,可靠性更高。通过模型泵试验证实了多学科设计优化提高了轴流泵叶片的综合性能,可有效兼顾高效、轻量化的要求。
Axial-flow pumps are widely employed in urban flood control and drainage pumping stations.The inlet vortex is one factor that seriously threaten the safe,stable and efficient operation of axial-flow pump units.In this paper,the vortex recognition performances of two vortex identification methods,the Q—criterion and Liutex methods,are compared based on an axial-flow pump,and the interactions between the impeller and vortex are explored.A flat plate vortex generator is installed in front of the impeller to continuously induce a stable vortex.The numerical simulation results show that the Liutex method can not only simultaneously identify strong and weak vortices but also reduce the influence of shear force at the sidewall.The vortex and the impeller influence each other.Under the influence of rotating blades,the vortex changes from a low frequency to the blade frequency,and the vortex significantly changes the tangential velocity inside the impeller.The accuracy of the numerical simulation results is verified by experiments on the external and internal characteristics.
