Investigation of an axisymmetric missile staging maneuver using time-accurate and steady-state computational fluid dynamics

Steady-state and time-accurate solutions of the Navier-Stokes equations have been obtained for the axisymmetric staging separation of a generic missile interceptor vehicle from its booster vehicle at a Mach number of 7.91. The vehicles are separated by a forward firing rocket motor located in the forward part of the booster vehicle. Hot and cold calorically perfect gas models of the separation motor exhaust jet were used for each case executed. Recommen-dations have been made to enhance the design process by integrating computational fluid dy-namics results with wind tunnel testing for similar configurations. The dynamic effects were predicted to be large for the cases of gap/D <0.1, and during separation motor startup. There-fore, wind tunnel testing in this region should not be solely relied upon to determine separation trajectories. Time-accurate CFD is a valuable tool for this phase of the separation maneuver and should be used to complement wind tunnel testing. It was also found that the separation rocket motor jet need not be modeled as a hot gas if gross vehicle forces are the only concern when the booster and interceptor have been separated with a gap/D greater than 0.1. If tem-perature sensitive instrumentation or control systems are being evaluated, hot jet modeling is required because large areas of flow separation occur on the interceptor vehicle which entrain hot gasses. Sensors in these locations could be affected.