EPA uses Harpoon and EnSight  for modeling winds in urban 
areas
  
                            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 
urban microenvironments.  
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). 
                 
              
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                        Image 
a shows selected velocity streamlines  originating from 
a vertical plane near the Madison  Square Garden building, and from a line near 
the  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 
              
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