Computational Fluid Dynamics and Experimental Data Comparison of a Missile-Model Roll Derivative

Abstract

The roll damping dynamic stability derivative for a modified basic finner missile at transonic and supersonic speeds is calculated using quasi-stationary and unsteady computational fluid dynamics models based on the Reynolds-averaged Navier–Stokes equations. The quasi-steady solution is time independent in a noninertial body-fixed steadily rotating reference frame including additional acceleration terms because of the transformation from the steady to the moving reference frame. In the unsteady approach, forced sinusoidal oscillations about the longitudinal body axis are modeled by employing a dynamic grid with a rigid-body option and a sliding interface between the moving and stationary parts of the grid. The numerical results are compared with experimental ones from the Arnold Engineering Development Center and T-38 wind tunnels. It is shown that the quasi-steady approach provides good approximation for the derivative if the spin rate is large enough, whereas the computational time is substantially shorter than for the transient model.