Research on base flow field and aerodynamic characteristics of the supersonic base bleed projectile

In order to study the aerodynamic characteristics of supersonic base bleed projectile, three dimensional Navier-Stokes equations with chemical reactions are solved using the upwind scheme (AUSMPW +), k-ω SST turbulence model, 8 species and 12 reaction kinetics model, and second-order turbulent combustion model. The reliability of the numerical methods have been validated firstly, then the real base bleed gas flow field of the supersonic base bleed projectile are numerically simulated. The rule of the effect of the attack angle and boattail angle on flow structures, together with aerodynamic characteristics are analyzed. Calculation results show that: attack angle has a certain influence on the flow structures. With the increases of attack angle, the area of the initial recirculation zone in both the windward and the leeward side increase, and the initial recirculation zone in the windward is always less than that in the leeward side; with the increase of attack angle, the aerodynamic coefficient, such as base drag coefficient and total drag coefficient, would increase; there has a best boattail angle under different conditions. The change of the boattail angle will change the flow structure in the base flow, and affect both the region and the strength of the secondary combustion of richfuel gas. The study results can provide a reference for the further study on drag reduction using base bleed and the design of base bleed projectile.