Degree Type

Dissertation

Date of Award

1986

Degree Name

Doctor of Philosophy

Department

Aerospace Engineering

Abstract

The transport, diffusion, and dry deposition of small particle material emitted from an idealized continuous line source into the atmosphere over a forward-facing step, a backward-facing step, and a rectangular block are stimulated. The description of the atmospheric flow pattern near the obstruction is obtained by numerically solving the Navier-Stokes equations with the k-(epsilon) two-equation turbulence model. Gosman's upwind finite difference scheme which is modified to be a time marching approach is selected as the numerical method. For the estimation of the pollutant concentration and deposition the gradient-transfer model is applied. The Crank-Nicolson scheme which is modified to be the Gauss-Seidel with Successive-Over-Relaxation method is used. Comparisons and analyses are performed based on these numerical predictions of the flow fields and particulate diffusion and deposition. The result is a better understanding of the properties of the disturbed atmospheric flow and of the distribution of suspended and deposited particles near the obstruction.

DOI

https://doi.org/10.31274/rtd-180813-5784

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Chin-Shun Lin

Language

en

Proquest ID

AAI8627130

File Format

application/pdf

File Size

133 pages

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