斜切反喷管性能计算

PERFORMANCE ANALYSIS OF SCARFED REVERSAL NOZZLE

关键词:  斜置喷管  推力反向  喷管气流  计算方法

Key words:  Canted nozzle  Thrust reversal  Nozzle flow  Calculation method

摘要:

本文提出了斜切反喷管流场计算方法,内部点用MacCormack二步显格式数值解控制方程,入口边界和固壁边界的参数用物理边界条件和可应用的沿双特征线的相容性方程计算.固壁边界计算中采用了激波装配技术和开关格式,有效地捕获了流场内的激波系列,计算中得到的激波情况和物理分析一致.本文在流场计算的基础上,进行了反喷管的性能计算.本文提出的方法可应用于反喷管的性能预估.

Abstract:

In this paper,the unsteady and inviscid governing equations of nozzle flow are solved by explicit MacCormack scheme which can automatically catch shock waves in flow field. The physical boundary conditions and the compatibility equations along valid bicharacteristic curves and pseudo-pathline are applied to inlet and solid wall points. In order to validly catch shock waves on the solid wall, the shock waves match technique and scheme switch etc.are used for computing parameters at solid wall points.The performance calculation is based on the computated flow field. The reverse thrust is calculated by summing the thrust component due to the scarfed nozzle extension wall pressure and the basic nozzle thrust.The calculated results are in agreement with that of physical analysis. The calculated value of the geometrical contraction factor is 0.8696 for the computed example.