Large-Eddy Simulation of plume dispersion within a regular array of cubic buildings

Nakayama, Hiromasa   ; Nagai, Haruyasu  

There is a potential problem that the intentional release of radioactive materials by terror attacks and the accidental spillage from the transportation or storage of flammable and toxic gas occur within populated urban area. For the assessment of human health hazard or the safety analysis of the hazardous gas, not only mean but also fluctuating concentrations should be estimated. Therefore, we have developed a high resolution atmospheric dispersion model using Large Eddy Simulation (LES) model and perform its simulation on plume dispersion within a regular array of cubic buildings as a first step and investigate the characteristics of mean and fluctuating concentrations. As a result, we can capture the unsteady behaviors of turbulent flow and plume dispersion within the building array and show the spatial distribution of mean and fluctuating concentrations.