M E 433
Professor John M. Cimbala
Lecture 14
Today, we will:
•
Continue our discussion of gradient diffusion and the Reynolds analogy
•
Begin to discuss the Gaussian plume model: how pollutants diffuse in plumes
The Gaussian Plume Model – useful for predicting the air pollution concentration
downwind of a smoke stack.
First (simplest) approximation: A point source of contaminant, with no buoyancy effects:
y
U
Top view
x
m j ,s
z
Side view
U
x
hs
Consider a small element of air in the plume of dimensions dx, dy, and dz as sketched here.
dz
dy
dx
z
y
x