Lateral Jet Interaction on a Finned Projectile in Supersonic Flow

Abstract

The flow interaction effects from a jet issuing into a supersonic crossflow are investigated using computational fluid dynamic simulations of a basic fin-stabilized projectile at moderate positive and negative angles attack. Data was generated for a high-pressure ratio jet located at seven locations along the projectile axis. Crossflow Mach numbers of 1.5, 2.5, and 3.5 were investigated for an angle of attack range of -10° ≤ α ≤ 10°. Flowfield visualizations indicated the size of the jet plume and the size of the resulting low-pressure region behind the jet were reduced as Mach number increased. The jet force amplification factor showed more variation as α became more negative. The effective jet location was found to vary little for α > -5° at Mach 2.5 and 3.5. For α > -5°, there was less variation of force amplification factor a Mach number increased. Flight simulations using reaction jet “squibs” were performed to evaluate the sensitivity of the control maneuver to the differences in jet thrust and jet actuation location. These results showed that significant differences in the projectile maneuver control were obtained if the effective jet thrust acting at the effective jet location were used instead of the ideal jet thrust acting at the jet exit location.