Rocket Exhaust Plume Secondary Smoke Formation Modeling

Our proposal addresses the inclusion of a secondary smoke model into a modern CFD code that is widely used for plume simulations. This will permit high fidelity simulations of dynamic, missile exhaust plume flowfields that, under certain conditions, produce a condensation cloud that can obscure the electromagnetic signals utilized for guidance and targeting. We will utilize a state of the art Navier-Stokes code that already contains much of the requisite physics (finite-rate chemistry, multiphase particulates, condensation/vaporization, etc.) in a dynamic grid framework that was developed to analyze extended plumes (launch to target) for tactical systems. In Phase I, we will implement and demonstrate the operation of an advanced secondary smoke model in the CRAFT CFDr code that will model the condensation of water vapor on heterogeneous nuclei in the presence of HCL. The resulting droplets will be composed of water only and droplets with variable water/acid compositions will be addressed in Phase II. We will assess the potential of the modeling approach for providing high fidelity predictions that can accurately simulate secondary smoke formation in tactical missile exhaust plumes under a broad range of conditions, and in our optional task, perform studies for a representative tactical missile system.