Flow Field for an Accelerating Axisymmetric Body
This study numerically investigates the compressible flow field near an axisymmetric body that is influenced by constant acceleration at 100 g where the motion is straight and level flight. Selected, instantaneous acceleration and deceleration results are compared to steady-state flow at corresponding projectile Mach numbers. The geometries tested were sharp 10° and 30° half-angle cone-cylinders with constant cylindrical aft section. Significant differences in the behavior of the flow field were found for the transonic Mach number range when compared with steady-state results. This was largely due to relative movement of the shock systems and their influence on the near flow field around the projectile. In particular, acceleration was found to delay the complete development of the bow shock and alter the expansion region at the cone-cylinder interface. Deceleration caused all shock structures to propagate upstream relative to the body and influence the nature of the flow field in a different manner compared to acceleration. The flow history concept was evident in both geometries and is demonstrated using simulation results from acceleration cases.