Trajectory Control of a Small Caliber Projectile Using Active Transpiration

A method to generate aerodynamic control forces for steering a small caliber projectile using flow transpiration channels on a boattailed afterbody is numerically investigated. Steady state simulations are conducted at Mach 2 from 0 to 10 deg angles of attack with zero sideslip angle using Reynolds Averaged Navier-Stokes equations and Reynolds Stress turbulence model. Results show that the interaction of the jet exiting from the transpiration channels with the main stream flow results in a complex three-dimensional shock wave structure on the projectile base yielding coherent vortex structures downstream of the primary interaction shock. The asymmetry induced in the flow due to three-dimensional coherent structures generated by natural flow transpiration near the projectile surface results in a considerable force which can be used for steering a small caliber projectile.