Multi-Physics, Multi-Scale CFD Modeling for Shock Effects on Droplet Interaction and Chemical Reaction

Multi-physics and multi-scale modeling is required for simulating the neutralization of chemical and biological agents in a liquid drop cloud environment that may be subjected to shock waves. Required physics include drop coalescence, breakup, mixing, liquid volume chemistry, and biological particle surface chemistry as individual drops interact. Shock waves will have a strong effect on drop size, drop velocity, and on agent/neutralizer chemistry. In this SBIR, CFD Research Corporation (CFDRC) will develop an innovative multi-scale modeling approach that includes a drop-drop interaction model for small scales and a Lagrangian spray model for medium scales to assess agent neutralization effectiveness. An existing small scale Volume of Fluid (VOF) drop-drop interaction model will be modified to include species mixing and chemistry at the sub-drop level. A medium scale agent neutralization model will be developed to simulate the interaction of order 1 million drops using a database of information from the small-scale model and incorporating the effects of shock waves. In Phase II, full chemistry and shock-drop interaction will be incorporated, a drop-drop interaction database will be developed and agent neutralization studies will be performed. The full simulation capability, including required software source code, will be transferred to the Air Force as a final deliverable.