Source Term Model for Fine Particles off Indoor Surfaces

Computational fluid dynamics (CFD) is a powerful tool for predicting the dispersion of chemicals and biological (CB) agents in indoor environments. Unfortunately, techniques to specify CB emissions as input to CFD simulations lack in sophistication. Adequate models are not available for many important CB emission processes. Particle resuspension from surfaces, particularly relevant to CB agents such as Anthrax, will be researched to develop models appropriate for CFD-based dispersion simulations. Phase I research will identify existing information relevant to indoor particle resuspension that will be used to develop source term models (STMs) capable of predicting particle resuspension rates. STM formulations will likely consider physical parameters such as particle size, surface characteristics such as roughness height, flow parameters such as turbulence intensity and shear stress, and particle-surface interactions such as electrostatic forces. Predictions of the STMs will be evaluated against measured particle fluxes available in existing resuspension studies. Preliminary demonstration of STM capabilities will be made through limited CFD simulations, and data gaps will be identified for further testing and evaluation in Phase II research.