Simulations of dispersion scenarios in downtown Chicago. Under the same wind conditions, few hundred feet displacement of the release source can lead to large differences in the downstream dispersion.
- The characterization of hazard dispersion is the focus of the present project. We are specifically interested in the details of the turbulence transport and mixing resulting from the complex topography during the initial cloud formation; in addition the effects of non-Newtonian dynamics and the presence of thermal stratification are being considered
- The description of the geometry is based on the Immersed Boundary method which has been modified to handle topography files in GPS format. Computational grids with anisotropic local grid refinement are automatically generated to capture the desired spatial scales in the vicinity of the release source.
- Computations are performed either using DNS/LES for isolated buildings, and by employing RANS modeling for large scale predictions. One specific focus of the project is the development of an accurate model of the turbulent scalar flux, based on generalized gradient diffusion hypothesis.
- The project is sponsored by the Army High Performance Computing Research Center
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R. Rossi and G. Iaccarino,
“Numerical simulation of scalar dispersion downstream of a square obstacle using gradient-transport type models”
Atmospheric Environment, Vol. 43, No. 16, pp. 2518-2531, 2009.
- D. Phillips, R. Rossi, G. Iaccarino, “Numerical simulation of scalar dispersion in separated flows using algebraic flux models “, 6th International Symposium on Turbulence, Heat and Mass Transfer, Rome, Italy, September 14-18, 2009.
- G. Iaccarino and R. Rossi, “DNS of scalar dispersion behind a square obstacle,” Army Science Conference, 2008.