二元收扩喷管设计参数对气动性能影响的数值研究

采用正交试验设计方法进行喷管气动性能数值模拟算例的设计，综合研究了二元收扩喷管8个设计参数对气动性能的影响，研究的设计参数包括圆到矩超椭圆型面过渡段几何参数（长径比、横截面积变化率、长半轴变化率、短半轴变化率）和主喷管段几何参数（喉部宽高比、喉部型面半径比、收敛半角、扩张半角），并且对喉部宽高比、喉部型面半径比、收敛半角、扩张半角等4个参数对喷管气动性能影响的灵敏度进行了分析.结果表明:喉部型面半径比R_W/R₈是二元收扩喷管气动性能影响的最主要参数，因此在喷管设计中应尽量增大R_W/R₈，尤其是在收敛半角α较大时，增大R_W/R₈可使喷管气动性能明显增大；喉部宽高比不是二元收扩喷管气动性能影响的主要参数；二元收扩喷管的气动性能几乎与过渡段型面无关. 

Numerical investigation of geometric parameters' influence to aerodynamic performance of two dimensional convergent and divergent nozzle

The computational cases were designed using the orthogonal experiment design method. The effect of eight geometric parameters on the aerodynamic performance of two dimensional convergent and divergent (2D-CD) nozzle was investigated. The geometric parameters studied include length to diameter ratio, cross-sectional area change rate, long half shaft rate, short half shaft rate of the super elliptic transition section, and throat width to height ratio, throat radius ratio, convergence half angle, divergent half angle of primary nozzle. The sensitivity analysis of throat aspect ratio, throat radius ratio, convergent half angle, divergent half angle on aerodynamic performance was performed. The results show that throat radius ratio is the main parameter of 2D-CD nozzle''s aerodynamic performance, therefore the throat radius ratio should be increased in the 2D-CD nozzle design, especially when the convergent half angle is larger. Width to height ratio of throat is not a major parameter of 2D-CD nozzle''s aerodynamic performance. The aerodynamic performance of 2D-CD nozzle is independent of transition duct.