Ph.D. Proposal Presentation by Diane C. Norris
Wednesday, October 1, 2003
(Drs. S. Mostafa Ghiaasiaan and Nolan Hertel, co-advisors)
"Transport and Dispersion of Pathogenic Particles in Buildings"
The protection of residential and commercial buildings against accidental or deliberate releases of hazardous biological and radiological particulates is expected to gain increasing importance in the future. This study is meant to establish a computational simulation-based methodology for the design, analysis, and optimization of buildings, where thermal efficiency and vulnerability to the spread, deposition, and inhalation of released hazardous particulates are simultaneously considered.
The developed methodology will be based on three levels of analysis that can be performed simultaneously or in tandem. At the first level, a three-dimensional transient analysis of the building, using a state-of-the-art building thermal design code that has been coupled with models that account for the transport and removal of particulates, will provide the macroscopic building thermal/air/particulate flow patterns, as well as estimates for the time-dependent abundance of radioactive and/or viable pathogenic particulates in various building locations. Computational fluid dynamic (CFD)-based simulations, enhanced with models representing the impact of biological activities of building residents on the local particulate population characteristics, will form the second level of analysis, and will provide detailed information about the flow and deposition of released material in sensitive areas in the building. Inhalation and dose calculations are then performed for various building locations in the third level of analysis, and the doses will be compared with EPA and other regulatory limits. This three-level analysis can be iteratively repeated to optimize the building design, identify locations best fitted for early detection or shelter, devise simple defensive action plans based on short-term manipulations of the building HVAC and other systems that would mitigate the spread of particulates, etc. The developed methodology will be demonstrated by appropriate scenario calculations.
The computational tools to be used in the developed methodology will be selected from available sources wherever possible. These will include, for example: EnergyPlus, a building thermal design code developed under the auspices of USDOE; FLUENT, a widely-used commercial CFD code capable of particulate transport analysis; and Mathematica, a commercial mathematical package that can provide dose calculations. These selected tools will all of course have to be enhanced in order to perform additional calculations mentioned earlier.