跨音速喷管流场波系分布的数值仿真

NUMERICAL SIMULATION OF WAVES CONSTRUCTION IN TRANSONIC NOZZLE FLOW

应用分离系数矩阵方法对跨音速喷管流场进行数值仿真，同时计算喷管内马赫波分布。采用５１５１个网格点的计算结果清晰反映出喷管内膨胀波和压缩波的生成和反射。数值仿真与实验结果在宽广马赫数范围内吻合一致，并揭示了波系分区分布，反映出波系影响下跨音速喷管流场参数分布的规律性。

The Split-Coefficient Matrix (SCM) method is manipulated here for the numerical computation of Euler equations so as to simulate the two dimensional axisymmetric transonic nozzle flow.The coefficient matrix is splitted directly by a set of simplified formula.A second order accurate explicit scheme is constructed to compute inner grid points.The scheme is free of artificial viscosity and is economical in terms of computer memory.5151 grid points are embedded into the nozzle flowfield and the computational results are in good agreement with experiments.Once the flowfield is known,the Mach waves characteristic relations are numerically solved by Euler method.Based on the graphic output of the Mach number and Mach waves in nozzle,it is possible to demonstrate not only the formation and reflection of an oblique shock within a tested nozzle geometry but also its peculiar zonal distribution of expansion and compression waves.As a result excellent consistency between parameter distribution and waves construction is revealed.