Transient, Rocket Exhaust Plume Modeling for Static Test Analyses

Our proposal addresses the high fidelity modeling of transient rocket exhaust plumes in a static test environment. Static testing provides a practical means of obtaining plume signature and interference data to support model validation. However, existing CFD codes routinely used for plumes in flight cannot accurately address many of the complexities associated with a static test environment. As such, we will extend an advanced state of the art Navier-Stokes code that contains much of the requisite physics (finite-rate chemistry, multiphase particulates, condensation/vaporization, etc.)and can operate in a dynamic grid framework. In Phase I, we will investigate the use of “all-speed” preconditioning techniques for mixed regions of high and low speed flow. We will formulate a technical approach to efficiently model a rocket motor exhausting into a quiescent environment including the effects of the test stand, the surrounding terrain, prevailing wind, and physical phenomena such as buoyancy, and secondary smoke formation. Procedures will be devised to accurately model the transient “start-up” and “shutdown” events of the rocket motor firing. We will demonstrate the ability of the extended model to analyze a transient rocket exhaust plume for a static test condition for a simplified geometrical configuration.