Advanced Computational Model for Rocket Plume Effects on Escape System Aerodynamic Characteristics

The proposed project will develop and adapt existing state-of-the-art computational tools for accurate prediction of ejection seat aerodynamic characteristics including rocket plume effects. The resultant CFD code will be based on the solution of the full Navier-Stokes equations with advanced turbulence and combustion modeling and will utilize a rocket plume model for capturing the shape and characteristics of the ejection seat rocket plumes. In Phase I, a 2D axi-symmetric rocket plume model will be developed to investigate ejection seat rocket nozzle and plume flows and their effects on surrounding flow field. Several techniques will be investigated for prescribing initial and boundary conditions within the three-dimensional ejection seat computational environment. The rocket plume model will be validated against experimental data for a wide range of free stream flow speeds. Also in Phase I, the rocket plume model will be loosely incorporated into the ejection seat computational environment and a demonstration calculation will be made for an ejecting seat with rocket power on. Several techniques for adaptive and/or local grid refinement, controllable propulsion and multi-nozzle systems will be studied for development/adaptation in Phase II. In Phase II, the rocket plume capability will be tightly incorporated into the ejection seat computational environment and the resultant CFD code will be extensively validated against wind Tunnel test data. Capability for multiple rocket propulsion and modulation of thrust levels will also be incorporated in Phase II.