关键词: 跨音速喷管;喷管气流;流动分布;矩阵算法;数值模拟

Abstract: he split coefficient matrix (SCM) method is improved for the numerical computation of Euler gas dynamic equations in nonconservative forms to simulate the transonic nozzle flowfields. Concise expressions for the direct coefficient matrix splitting are derived and presented in the paper, the related matrix splitting computation work is consequently greatly reduced and simplified. By referring to Beam-Warming’s explicit finite difference scheme, a second-order accurate scheme in consistence with SCM method is constructed and analysed. Besides conventional local time stepping to accelerating the convergence of steady state calculation, an additional option is switched on to setting the parameter C differently at each mesh point according to its local Mach number. The measure results a quicker convergence. Although there is an oblique shock within the nozzle supersonic flow region, it revealed that the algorithm being used is still robust even if without any artificial parameter to control the numerical instability. Computational results are in good agreement with experiments in a wide range of Mach number.

Key words: Transonic nozzle;Nozzle gas flow;Flow distribution;Matrix algorithm;Numerical simulation