一种新型多维通量函数在求解平面叶栅跨音速流动的应用

APPLICATION OF A MULTI-DIMENSIONAL FLUX FUNCTION TO ANALYSIS OF PLANE TRANSONIC CASCADE FLOW

采用一种改进的Ｒｏｅ格式对平面叶栅的无粘流动进行了数值模拟，并与Ｒｏｅ格式的计算结果进行了比较。采用四阶Ｒｕｎｇｅ－Ｋｕｔａ时间差分格式，空间三阶有限体积法。网格生成采用贴体网格近壁面修正的方法。计算结果表明，该格式在减少格式对网格的依赖性，抑制数值粘性方面具有明显的作用。

In two-or three-dimensional flow fields,it is difficult to determine the direction of wave propagation in cascades due to complexity of transonic flow.Now a grid-independent approximate Riemann solver is applied to numerical simulation of two-dimensional transonic cascade flow by the Euler or Navier-Stokes equations.Fluxes on grid faces are obtained via wave decomposition,assuming that information propagates in the velocity difference directions,rather than in the grid-normal directions as in a standard grid-aligned solver.Second-order computations with the grid-independent flux function are used to analyze two typical examples of transonic cascades.The results indicate that the grid-independent model suppresses entropy production over the cascade surface due to either computational diffusion or grid viscosity,and resolves shock and shear waves in transonic flow of cascades much better.