Extended, Transient, Rocket Exhaust Plume Modeling

"The extended transient exhaust plume from hypervelocity tactical missiles contains particulates which degrade EM waves used for guidance and/or tracking. Our proposed Phase I effort initiates the development of an efficient parallel architecture frameworkto analyze the complete transient plume, from launch to target, using specialized Navier-Stokes methodology in a dynamic and expanding grid system. A multiple time-scale formulation is used to treat the disparate scales in the plume nearfield, farfield,and atmospheric dispersion domains. Efficiency strategies will be examined using a sequence of quasi-steady solutions. A key element of our Phase I work entails the inclusion of RANS particle dispersion methodology which utilizes a Lagrangian particlesolver and implements stochastic methods to emulate the turbulent eddy structure. The eddy structure for high speed plumes differs substantially from that in lower speed laboratory jets and we will use LES simulations with particles to provide data athigher speeds. An optional task entails use of our dynamic grid, incompressible unstructured code to simulate atmospheric dispersion over an ever expanding and moving domain using Lagrangian methodology within an LES framework. A demo calculation will beperformed for a CKEM type missile over a complete trajectory. The ability to deal with the extended transient plume problem has significant commercial potential as related to a variety o