EPA uses Harpoon and EnSight
for modeling winds in urban
The U. S. Environmental Protection Agency's (EPA) National
Exposure. Research Laboratory is working with the US EPA's Scientific
Visualization Center on the Urban Microenvironments
project. The project simulates human exposure to environmental pollutants in
Understanding the pathway of air pollutants from its source to human exposure
in urban areas has been an ongoing activity for many years, but has recently
been dramatically enhanced by new methods using visualization of CFD
computations. Computed wind fields are used to estimate and visualize air
pollution transport in urban areas. Visualization methods are critical to
understanding the complex wind fields.
This series of images shows wind fields near Madison Square
Garden in New York City. CEI's Harpoon was used to create a 19 million
cell mesh for the application, and Fluent, Inc CFD computation was used
to simulate the wind field. The calculation was a steady-state average
wind field used to provide cell specific wind velocity vectors and
calculated velocity streamlines. Visualization was
done in EnSight Gold.
Images courtesy of project principal
investigator Dr. Alan Huber, U.S. EPA National Exposure Research
Laboratory, and Dr. Matt Freeman, a contractor with the U.S. EPA's Scientific
Visualization Center (managed by Heidi Paulsen).
a shows selected velocity streamlines
a vertical plane near the Madison
Square Garden building, and from a line near
surface along 7th Avenue.
Image b shows a vertical
slice of mesh.
Image c shows a horizontal
slice of the wind field
near the ground