双钟型喷管高度补偿特性的数值分析

Numerical analysis on the performance of dual-bell nozzle

针对双钟型喷管流场中存在的激波、激波与附面层相互作用、大尺度分离流动等复杂的物理现象,应用RNGk ε湍流模型封闭二维粘性可压缩N S方程组,采用二阶迎风格式及隐式Gauss Seidel迭代方法进行耦合求解,对双钟型喷管流场进行数值模拟研究。结果表明,双钟型喷管在低空出现壁面可控流动分离,避免了过膨胀现象,性能优于大面积比钟型喷管;在高空下为完全附着流动,性能优于小面积比钟型喷管,实现了高度补偿特性。

To gain insight into the performance and flow behavior of dual-bell nozzles, extensive numerical simulations at different ambient pressures were performed. Due to the complex flow characteristics such as shocks and flow separation, the RNG κ-Ε turbulence model is selected to solve the 2D compressible N-S equations. Compared with two conventional bell nozzles, the dual-bell nozzle shows significant performance gains resulting from the altitude adaptation of the exhaust flow to the ambient pressure. Forced flow separation at sea level mode and full flow at altitude mode are observed as expected.