Abstract
In an environmental assesment, there are many small sources with an initial plume spread. In these cases they are often treated as an area source. There are several methods used for the prediction of concentration patterns from an area source.
1) Integrated finite line source method.
2) Imaginary point source method.
3) Integrated infinite line source method.
In this paper, two new practical models for a rectangular shaped area source are developed. These models are derived by integrating the Gaussian plume model approximately. In this process, an area source is replaced by an equivalent imaginary line source. The position of the imaginary source movesaccording to the downwind distance and stability.
These models are applied under the following conditions: 1) initial vertical spread; 2, 5m, 2) effective stack height; 1-50m, 3) stability class; A, D, F, G, 4) 1km×1km area source.
These models show the quite satisfactory agreement with the numerical integration method. These are also applicable for the oblique wind case by using the Gaussian plume approximate modelof a line source for oblique wind. And it has also shown that the proper usage of these models enables us to use much less calculating time than that of the integrated finite line models.
Finally the effective standards for these models usage are shown.
