关键词: 流体力学, 底部排气弹, 底部阻力, 底压比, 减阻特性

Abstract: 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.

Key words: fluid mechanics, base bleed projectile, base drag, base pressure ratio, drag reduction cha-racteristics