Date of Graduation
Doctor of Philosophy in Engineering (PhD)
Tom O. Spicer III
Second Committee Member
Third Committee Member
Fourth Committee Member
Along-wind Dispersion, Atmosphere, Finite-duration Releases, Modeling, Wind Tunnel
Along-wind dispersion, or stretching of the cloud in the direction of the wind, plays an important role in the concentration and modeling of contaminant releases in the atmosphere. Theoretical and empirical derivations were compared for appropriate parameterization of along-wind dispersion. Available field data were analyzed to evaluate and improve previous parameterizations of the along-wind dispersion coefficient, σ_x. An experimental test program was developed and executed in an ultra-low speed wind tunnel at the Chemical Hazards Research Center to determine the effects of the time distribution coefficient on true finite-duration releases from an original area source. Multiple wind speeds, release durations, and downwind distances were investigated with ensemble averages for improved quality of the cloud characteristics for each set of test conditions. An overall relationship between the time of peak arrival (TOPa) and the time distribution coefficient σ_t= 0.23*TOPa was demonstrated across all parameters. From this relationship, the along-wind dispersion coefficient can be accurately predicted and scaled appropriately. Additional relationships for the leading and trailing edges of the cloud are appropriately modeled.
Morris, Jessica M., "Experimentation and Modeling of the Effects of Along-Wind Dispersion on Cloud Characteristics of Finite-Duration Contaminant Releases in the Atmosphere" (2018). Theses and Dissertations. 3088.