Numerical Investigation of Canard-Controlled Missile with Planar and Grid Fins

Abstract

Viscous computational fluid dynamic simulations were used to predict the aerodynamic coefficients and flowfield around a generic canard-controlled missile configuration in supersonic flow. Computations were performed at Mach 1.5 and 3.0, six angles of attack between 0 and 10 deg, with 0- and 10-deg canard deflection, and with planar and grid tail fins, for a total of 48 cases. Validation of the computed results was demonstrated by the very good agreement between the computed aerodynamic coefficients and those obtained from wind-tunnel measurements. Visualizations of the flowfield showed that the downwash off of the canards produced a low-pressure region on the starboard side of the missile that, in turn, produced an adverse side force. The pressure differential on the leeward fin produced by the interaction with the canard trailing vortices is primarily responsible for the adverse roll effect observed when planar fins are used. Grid tail fins improved the roll effectiveness of the canards at low supersonic speed. Flow visualizations from the simulations performed in this study help in the understanding of the flow physics and can lead to improved canard and tail fin designs for missiles and rockets.