矢通量分裂显式格式及二元喷管射流模拟

A FLUX VECTOR SPLITTING EXPLICIT SCHEME AND SIMULATION OF 2-D NOZZLE′S PROPULSIVE JET

本文在较常用的显式两步格式的基础上 ,采用 Steger- Warming形式的矢通量分裂 (简称矢分或 FVS)的原理 ,提出了一种矢分二阶精度显式两步格式。在分析了格式的各种特性后 ,与Mac Cormack格式进行了实算对比。又给出了某二元喷管射流问题的模拟实例。计算结果表明 ,矢分与该显式格式的配合具有矢分法的基本优点和计算稳定、速度较快的优点。

On the basis of two steps explicit methods,author investigates the application of the theory of Flux Vector Splitting(FVS)of J.L.Steger and R.F.Warming.Besides the simplified split flux vector formula,a new explicit scheme is proposed for solving hyperbolic differential equatione.It is a explicit two steps FVS scheme of second order accuracy.At first it was compared with MacCormack′s scheme issued in 1972(MC72)in numerical computation.And finally a 2-D flow of a rectangular nozzle with its jet plume was analysed numerically by the present scheme.The results indicate some high performances of the present scheme:1.Numerical vibrations near the front surface of shock waves vanish.2.The scheme runs without artificial viscosity.3.It takes just as much time as MC72 takes to solve a flow field.The scheme features the higher inherent viscosity of the scheme compared with that of MC72.