Integrated high performance computational tools for simulations of transport and diffusion of contaminants in urban areas

摘要

Rapid analysis of transport and diffusion of chemical and biological aerosols and contaminants in an urban environment is a critical part of any homeland security response team. High performance computing (HPC) is a valuable technique for such analysis. The time constraint needed to create fully developed complex 3D city terrain models to support such dispersion simulations requires a task of converting agency data to the format necessary on the simulation platform. Numerous data sets have been employed in the development of complex 3D city models. Such data include the use of multi-layer building morphology data, the use of geographic information system (GIS) based shapefiles and digital elevation models (DEM), and the use of remote sensing data such as Light Detection and Ranging (LIDAR). The constructed geometry models are used to generate large-scale computational domains on a platform that supports our HPC tools. These tools include fully automated unstructured mesh generation, parallel and scalable flow solvers based on stabilized finite element formulations and a remote client-server environment for large-scale flow visualization. The stabilized finite element formulations, which are based on the SUPG and PSPG techniques, are parallelized and vectorized on the Cray X1. The 3D validation problem involves transient simulation of flow past a building with a source point releasing traces. A 3D application problem is presented to demonstrate the capability of the integrated HPC tools.