Time-Accurate Calculations of Free-Flight Aerodynamics of Maneuvering Projectiles

This paper describes a multidisciplinary computational study undertaken to model the flight trajectories and the free-flight aerodynamics of finned projectiles both with and without control maneuvers. Advanced computational capabilities both in computational fluid dynamics (CFD) and rigid body dynamics (RBD) have been successfully fully coupled on high performance computing (HPC) platforms for "virtual fly-outs" of munitions similar to actual free flight tests in the aerodynamic experimental facilities. Time-accurate Navier-Stokes computations have been performed to compute the unsteady aerodynamics associated with the free flight of a finned projectile at a supersonic speed using an advanced scalable unstructured flow solver on a highly parallel Linux cluster. Some results relating to the portability and the performance of the flow solver on the Linux clusters are also addressed. Computed positions and orientations of the projectile along the flight trajectory have been compared with actual data measured from free flight tests and are found to be generally in good agreement. Computed results obtained for another complex finned configuration with canard-control pitch-up maneuver in a virtual fly-out show the potential of these techniques for providing the actual time-dependent response of the flight vehicle and the resulting unsteady aerodynamics for maneuvering projectiles.