Numerical Investigation of Aerodynamics of Canard-controlled Missile Using Planar and Grid Tail Fins

Book excerpt: Viscous computational fluid dynamic simulations were used to predict the aerodynamic coefficients and flow field around a canard-controlled missile in subsonic and transonic flow. Computations were performed at Mach 0.6 and 0.9, six angles of attack between 0 deg and 10 deg, and with planar and grid tail fins. The computations were validated with wind tunnel data. Flow visualizations showed that the canard downwash produced a low-pressure region on the starboard side of the missile that produced a large induced side force. The canard trailing vortices interacted with the tail fins until alpha> 8 deg, producing a pressure differential on the leeward tail fin, leading to the adverse induced roll effects. Visualizations of the flow through the grid fin structure showed choking of the flow at Mach 0.9 and Mach 1.5. The validated simulations results showed that grid fins did not improve the canard roll-control effectiveness at subsonic and transonic speeds as well as they did at the low supersonic speed.