Computation of a controlled store separation from a cavity

Coupling of the Reynolds-averaged Navier-Stokes equations, rigid-body dynamics, and a pitch-attitude control law is demonstrated in two and three dimensions. The application problem was the separation of a canard-controlled store from an open-flow rectangular cavity at a freestream Mach number of 1.2. The transient flowfleld was computed using a diagonal scheme in an overset mesh framework, with the resultant aerodynamic loads used as the forcing functions in the nonlinear dynamics equations. The proportional and rate gyro sensitivities were computed via pole placement techniques for the linearized dynamical equations, in which computed aerodynamic stability derivatives were used. In two dimensions, a comparison between full and linearized flow equations for a perturbed pinned missile was made, and a controlled store was found to possess improved separation characteristics over a canard-fixed store. In three dimensions, trajectory comparisons with quasisteady wind-tunnel data for the canard-fixed case were made. Comparisons of canard-fixed and canardactive simulations showed that controlled store offers only modest improvements in cavity separation characteristics for these high-ejection rate cases.