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. The CRAFT CFDr Navier-Stokes code used already contains much of the requisite physics (finite-rate chemistry, multiphase particulates, condensation/vaporization, etc.) in a dynamic grid framework developed to analyze extended plumes (launch to target) for tactical systems. We will implement and demonstrate the operation of an advanced secondary smoke model that will analyze condensation of water vapor on heterogeneous nuclei in the presence of HCl. The resulting droplets will be composed of either water and/or variable water/acid compositions. The modeling implements both an Eulerian particulate cloud framework as well as a Lagrangian particulate tracking framework. We will assess the potential of this 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 will perform studies for representative tactical missile scenarios.