基于CPPID柱面投影设计方法的氢液化器氦透平膨胀机叶轮优化与流场分析OA

This paper addresses the lack of explicit physical mapping between blade geometry and internal flow in traditional impeller design methods for cryogenic turbine expanders.A cylindrical projection parametric impeller design method(CPPID)is proposed.This method enables precise parametric control of the three-dimensional impeller flow path by shaping the projected curves of the blade profiles(at the hub,center,and shroud)onto their respective reference cylindrical surfaces.The high-efficiency impeller of a 5 t/d hydrogen liquefier's final-stage helium turbo-expander(TEX3)served as the baseline for optimization.Maintaining constant refrigeration power and incidence angle,a systematic analysis of the key design parameter(Tu)was conducted.Numerical results demonstrate that the impellers redesigned using the CPPID method achieve higher isentropic efficiency while requiring less mass flow rate for the same refrigeration power.The center layer profile had the most pronounced impact on overall performance,while the shroud layer profile effectively manipulated vortex structures and suppressed high-loss passage vortices;the hub layer showed relatively minor influence.Specifically,the extremely concave shroud blade profile achieved an isentropic efficiency increase from 89.528%to 91.887%.This study validates the effectiveness of the CPPID method,providing a new approach for the refined design of high-performance turbo-expander impellers.