应用复合型网格求解叶栅气动设计杂交型问题

建立在流线坐标系上的叶栅气动设计反命题与杂交命题是在映象平面(由流线坐标与周向坐标构成H上求解的.以往在映像平面只采用H型网格,本文首次将H加C型复合网格用于这类反命题计算,使叶栅前缘附近网格构造趋于合理,从而明显提高了计算精度.本文采用的解法是基于叶轮机气动变分原理的有限元方法.

Calculation of hybrid problems for aerodynamic design of cascade using combined mesh

The hybrid problems based on the streamline coordinates have to be solved in the image plane, which is composed of streamline and circumferential coordinates. Therefore, in the physical plane, the mesh shape is unknown until the equations have been solved. Up to date, only H-type mesh has been used in the image plane. The distortion of the cells close to the leading edge in the physical plane often causes serious difficulties to the solution. In this paper, the combined mesh of H+C type is firstly employed to solve such kind of hybrid problems, which improves the quality of mesh structure near the leading edge, and thus leads to an higher accuracy. Although mesh distortion still happen sometimes, the combined mesh has the possibility to be adjusted to get a normal shape. Some measurements to adjust the mesh have been mentioned. The algorithm used in this paper is the FEM approach based on the variational principle of gas dynamics in turbomachinery.