A Validation of FEM3MP with Joint Urban 2003 Data
Under the sponsorship of the U.S. DOE and DHS, we have recently developed a computational fluid dynamics (CFD) model for simulating airflow and dispersion of chemical/biological agents released in urban areas. Our model, FEM3MP, is based on solving the three-dimensional, time-dependent Navier-Stokes equations with appropriate physics submodels on massively parallel computer platforms. It employs finite-element discretization for effective treatment of complex geometries and a semi-implicit projection scheme for efficient time-integration. A simplified CFD approach, using both explicitly resolved and virtual buildings, was implemented to further improve the model's efficiency. Predictions from our model are continuously being verified against measured data from wind tunnel and field studies. Herein our model is further evaluated using observed data from IOPs (intensive operation periods) 3 and 9 of the Joint Urban 2003 field study conducted in Oklahoma City, Oklahoma, in July 2003. Our model predictions of wind and concentration fields in the near and intermediate regions, as well as profiles of wind speed, wind direction, friction velocity, and turbulent kinetic energy (TKE) in the urban wake region, are generally consistent with and compared reasonably well with field observations. In addition, our model was able to predict the observed split plume of IOP 3 and the end vortices along Park Avenue in IOP 9. The dispersion results and TKE profiles at the crane station indicate the effects of convective mixing are relatively important for the daytime release of IOP 3 but the stable effects are relatively unimportant for the nighttime release of IOP 9. Results of this study also suggest that the simplified CFD approach implemented in FEM3MP can be a cost-effective tool for simulating urban dispersion problems.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 929163
- Report Number(s):
- UCRL-JRNL-220878-REV-1; JOAMEZ; TRN: US200815%%214
- Journal Information:
- Journal of Applied Meteorology, Vol. 46, Issue 12; ISSN 0894-8763
- Country of Publication:
- United States
- Language:
- English
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