High-Alpha Prediction of Roll Damping and Magnus Stability Coefficients for Finned Projectiles

The roll damping and Magnus dynamic stability coefficients, as well as total force and moment coefficients, were numerically computed at high angles of attack up to 90deg for two generic fin-stabilized flight munitions at a supersonic Mach number of 2.49. The aerodynamic coefficients were computed via time-accurate Reynolds-averaged Navier-Stokes numerical methods, and they were compared with archival wind-tunnel data. Fair to excellent comparisons with the experiment were obtained for the coefficients for the full angle-of-attack range, except for the axial force, which was overpredicted at higher angles of attack. Numerical modeling parameter studies were conducted to include dependence on spin rate, grid resolution, temporal resolution, and other numerical convergence parameters.