Development of a Unified Stochastic-Hydrodynamic Simulation EnviRonment (USHER) for Biological Agent Neutralization and Defeat

The overall objective of this proposal is to design, develop and demonstrate an integrated "Virtual Numerical Laboratory" (USHER) for simulational evaluation of biological agent defeat strategies. Traditional Computational Fluid Dynamics (CFD) calculations of agent neutralization, based on deterministic chemical kinetics can lead to misleading conclusions. We propose to develop a novel, stochastic formalism to describe agent-neutralizer interactions and tightly integrate it into an incompressible CFD framework with coupled turbulence and moving body models. CFD-ACE+, an industry leading multiphysics simulation software, will be used as the development platform. The proposed effort will leverage on several recent research advancements in CFD-ACE+ including a novel Surface Marker Point approach and Chimera formulation for moving boundary calculations as well as Large Eddy Simulations (LES) for turbulent flow modeling. During Phase I, stochastic agent-neutralizer interactions will be represented via a convection-coupled Fokker-Planck description. The applicability of this model will be demonstrated in a test environment featuring projectile penetration and agent neutralization in a container. The more complex Master-Equation (growth/death) approach will be formulated. In Phase II, further development and numerical implementation of all models (stochastic kinetics, moving body) will be completed. Demonstration of the new simulation capability in a government approved test scenario is planned.