关键词: 超声速流动, 底部排气技术, 底部排气形式, 底压比, 减阻性能

Abstract:

In order to research on the base bleed for drag reduction in a supersonic flow, three dimensional Navier-Stokes equations with chemical reactions are solved by the high-accuracy and high-resolution upwind scheme (AUSMPW +), k-ω shear stress transport (SST) turbulence model, the 8 species and 12 reaction kinetics model, and the second-order turbulent combustion model. The base bleed flow field is numerically simulated in a supersonic flow. The rule and mechanism are analyzed of the effect of base bleed type on flow structure and drag reduction performance in the supersonic flow. Calculation results show that: from the drag reduction performance point of view, with the increase of base bleed parameters, the base pressure ratio tends to continuously increase using the edge type, while the base pressure ratio using the center type tends to increase first, and then decrease; from the flow structure point of view, with the increase of base bleed parameters, the flow structure using the center type changes greatly, the position of the front and rear stagnation point changes significantly and finally disappears, and the initial recirculation zone is gradually pushed until it disappears, while there is basically no significant change in the flow structure with the edge type-the position of front stagnation point is always the same, the position of rear stagnation point is pushed backward, and the initial recirculation zone always exists. These results can provide useful reference for the engineering application of base bleed projectiles.

Key words: supersonic flow, base bleed technology, base bleed type, base pressure ratio, drag reduction performance