透平机械叶轮叶片三维参数化造型及六面体网格生成方法研究

叶轮是向心透平和离心压缩机中的重要部件,其几何形状比较复杂,采用良好的网格进行有限元分析,以获得精确的强度和振动特性,是其安全性的重要保证.针对叶轮结构特点,采用CAGD (computer aided geometric design) 技术实现叶轮的三维实体参数化造型;然后使用同胚原理和BMSweeping(sweeping via background mesh interpolation)等方法建立叶轮六面体网格生成方法.为了保证有限元分析的精确性,建立叶轮上叶片根部倒角、轮盘气道进口处等特殊结构的网格生成方法.100 kW微型燃气轮机的向心叶轮网格划分表明, 使用上述方法生成的网格质量较高,能很好地满足有限元分析要求.

STUDY ON THREE DIMENSIONAL PARAMETRIC FEATURE MODELING METHOD AND GENERATION OF HEXAHEDRON MESH FOR IMPELLER AND BLADE OF TURBOMACHINERY

Impeller is a key component of centripetal turbine and centrifugal compressor and has very complex geometry.It is very important to obtain accurate numerical results by FEA(finite element analysis) using perfect mesh.Based on the structural feature of impeller,CAGD(computer aided geometric design) was adopted to develop its three dimensional parametric feature modeling method.Then homeomorphism principle and other methods as BMSweeping(sweeping via background mesh interpolation) and so on were used to develop generation method of hexahedron mesh for impeller.In order to improve accuracy of numerical results by FEA,some special mesh generation methods for fillet on the bottom of blade and inlet of flow channel have also been developed to obtain good mesh.The mesh for a centripetal impeller of a 100 kW microturbine was generated,it shows the mesh is perfect and can satisfy the requirement of FEA.