Numerical Prediction of Pitch Damping Stability Derivatives for Finned Projectiles

Abstract

Reynolds-averaged Navier–Stokes computational fluid dynamics and linear flight mechanics theory were used to compute the pitch damping dynamic stability derivatives for two basic finned projectiles using two numerical methods, namely, the transient planar pitching method and the steady lunar coning method. Numerical results were compared with free-flight and wind-tunnel experimental data for Mach numbers in the range of 0.5–4.5. The accuracy, efficiency, and dependence of these methods on various aerodynamic and numerical modeling parameters were investigated. The numerical methods generally showed good agreement with each other, except at some transonic Mach numbers. Both methods showed good to excellent agreement with experimental data in the high transonic and supersonic Mach regimes. In the subsonic and low transonic regimes, agreement between numerical and experimental data was less favorable. The accuracy of the free-flight test data in these regimes was uncertain due to instances of large scatter, large standard deviation errors, and different data sources showing significantly different results.