Navier-Stokes Computations of Projectile Base Flow at Transonic Speeds with and without Base Injection

Abstract

Abstract : A computational capability has been developed for predicting the flow field about the entire projectile, including the recirculatory base flow, at transonic speeds. Additionally, the computer code allows mass injection at the projectile base and hence is used to show the effects of base bleed on base drag. Computations have been made for a secant-ogive-cylinder projectile for a series of Mach numbers in the transonic flow regime. Computed results show the qualitative and quantitative nature of base flow with and without base bleed. The reduction in base drag with base bleed is clearly predicted for various mass injection rates and for Mach numbers .9 M 1.2. The encouraging results obtained indicate that this computational technique may provide useful design guidance for shell with base bleed.