At a time when it is unfortunately very topical, CFDRC has been awarded a contract to develop simulation tools to model the dispersal of nuclear, chemical, biological, and radiological (NCBR) substances in urban areas.
The tool, dubbed the Urban Dispersion Simulator (UDS), must overcome such modeling obstacles as geometry acquisition, meshing, and attaining a solution on building to city blocks scale. Additionally, prevailing wind and turbulence fields, buoyancy, solar radiation, tree-induced flow losses, HVAC effects, and the dispersal of gas-phase agents as well as solid and liquid dispersants must be considered.
To facilitate rapid modeling of such large-scale structures, CFDRC has hit upon an image based approach to model generation. By analyzing an image representing a height map of the area of interest, a voxel-based solid model is created. The solid model is then used to create a CFD mesh using a 2N tree-based mesh generator.
The UDS development is being funded under a Small Business Innovation Research contract through the Defense Threat Reduction Agency.