超声速流动中底部排气减阻的数值研究

为了研究超声速流动中底部排气减阻特性，采用高精度的AUSMPW+迎风格式、k-ω SST湍流模型、8组分12反应化学动力学模型、二阶矩湍流燃烧模型耦合求解三维带化学反应的Navier-Stokes方程。在数值方法的有效性和可靠性经过验证后，对超声速流动底部排真实气体流场进行了数值模拟。计算结果表明：随着排气参数的增大，底压比将先增大后减小，然后再增大；当排气参数较小时，底压比基本不随排气面积的改变而改变。当排气参数较大时，底压比随着排气面积的增大而增大；在最佳排气减阻区内，提高排气总温对提高底压比是有利的；底部排气中富燃气体含量越高，则二次燃烧越强，有利于提高底压比。研究结果可为底部排气弹工程应用提供参考。

Numerical Research on Drag Reduction of Base Bleed in Supersonic Flow

In order to research the drag reduction characteristics of base bleed in supersonic flow, three-dimensional Navier-Stokes equations with chemical reactions are solved by the high-accuracy upwind scheme (AUSMPW+), k-ω SST turbulence model, 8 species/12 reaction kinetics model, and second-order turbulent combustion model. The flow field based on the actual base bleed gas in supersonic flow is numerically simulated by verifying the effectiveness and reliability of the numerical methods. The calculated results show that, with the increase in base bleed parameter, the base pressure ratio increases and then decrease, and finally it tends to increase. When the base bleed parameter is small, base pressure ratio does not change with base bleed area. While base bleed parameter is large, the base pressure ratio increases with base bleed area. Increasing the temperature of base bleed gas is favorable to increase the base pressure ratio. The intensity of the secondary combustion improves with the increase in the content of fuel-rich gas in base bleed gas, which can improve the base pressure ratio. The results can provide reference for the engineering application of base bleed projectile.