| Main Title |
Turbulent Diffusion from a Point Source in Stratified and Neutral Flows Around a Three-Dimensional Hill-Part I. Diffusion Equation Analysis. |
| Author |
Snyder, W. H. ;
Hunt, J. C. R. ;
Puttock, J. S. ;
|
| CORP Author |
Environmental Sciences Research Lab., Research Triangle Park, NC. Meteorology and Assessment Div. |
| Year Published |
1979 |
| Report Number |
EPA-600/J-79-048; |
| Stock Number |
PB80-163058 |
| Additional Subjects |
Air pollution ;
Turbulent flow ;
Mathematical models ;
Hills ;
Plumes ;
Concentration(Composition) ;
Reprints ;
Foreign technology ;
Atmospheric dispersion ;
Three-dimensional calculations
|
| Holdings |
| Library |
Call Number |
Additional Info |
Location |
Last
Modified |
Checkout
Status |
| NTIS |
PB80-163058 |
Some EPA libraries have a fiche copy filed under the call number shown. |
|
07/26/2022 |
|
| Collation |
14p |
| Abstract |
In stable stratified flow around three dimensional hills, vertical motion and vertical diffusion is negligible. Consequently turbulent diffusion from a point source can be modelled by considering horizontal flow and horizontal diffusion. Using an eddy diffusivity, the advective diffusive equation around a three dimensional hill which is axisymmetric about a vertical axis is solved to show how source positions on and off the center line affect the trajectories and splitting of impinging plumes and the value and position of the maximum surface concentration on the hill. In the second part of the paper a plume is analyzed in a neutrally stable potential flow around an axisymmetric obstacle such as a hemisphere, also using the diffusion equation. The solutions show how, because streamlines approach the surface of a 3-dimensional hill much more closely than the surface of a 2-dimensional hill, the maximum surface concentrations on the hill can become very much greater than in the absence of the hill. But this only occurs for a limited range of source heights. |
| Supplementary Notes |
Prepared in cooperation with Atmospheric Environment Service, Downsview (Ontario), and Cambridge Univ. (England). Dept. of Applied Mathematics and Theoretical Physics. Pub. in Journal of Atmospheric Environment, v13, p1227-1239 1979. |
| NTIS Title Notes |
Journal article. |
| Title Annotations |
Reprint: Turbulent Diffusion from a Point Source in Stratified and Neutral Flows Around a Three-Dimensional Hill-Part I. Diffusion Equation Analysis. |
| PUB Date Free Form |
1979 |
| Category Codes |
4B; 68A; 55B |
| NTIS Prices |
PC A02/MF A01 |
| Primary Description |
600/09 |
| Document Type |
NT |
| Cataloging Source |
NTIS/MT |
| Control Number |
323777132 |
| Origin |
NTIS |
| Type |
CAT |
