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

The overall objective of this effort is to design, develop and demonstrate an integrated “Virtual Numerical Laboratory” for evaluation of biological agent defeat strategies. The simulation framework will integrate a novel, stochastic description of agent-neutralizer interactions/distribution with an incompressible CFD code with advanced turbulence, moving body and free surface models. In Phase I, a novel Master-Equation based stochastic formalism of agent-neutralizer interactions was developed and integrated, in a consistent manner, with (a) Surface Marker Point approach for moving body calculations, (b) Large Eddy Simulation (LES) and Reynolds Averaged Naviér-Stokes (RANS) methods for turbulence computations, and (c) Volume-of-Fluid (VOF) for free surface modeling. The model framework was verified and validated and proof-of-concept/value clearly demonstrated. During Phase II, we will further develop the stochastic models to include a wide range of agent-neutralizer combinations, along with approaches for modeling uncertainty in the initial distribution of bioagent within the target. Neutralization model fidelity will be maximized by inferring information from semi-classical pathogen population experiments and quantitative models of cellular physiological processes. Hydrodynamic models will be further enhanced by coupling advanced turbulence and free-surface models with the Surface Marker approach. Extensive model/software testing and demonstration will be performed. Modular software, along with an easy-to-use interface and detailed documentation will be developed and transferred to the Air Force at the end of the project.