Evaluation of a Gaussian plume model for urban canopy using CFD data

Nakayama, Hiromasa   ; Takemi, Tetsuya*; Nagai, Haruyasu  

The Gaussian plume model is widely used for regulatory purposes due to its simplicity and low cost. The traditional Gaussian model is effective for a flat or nearly flat terrain but has limited applicability for densely built-up urban areas. However, urban surface geometries are highly inhomogeneous and covered with low- and high-rise buildings. Therefore, important issues remain in appropriately determining the representative wind speed and dispersion parameters within urban canopy. In this study, first we carried out LESs of plume dispersion in various urban areas and investigated canopy wind speed, lateral and vertical plume spreads. Then, we estimated the representative canopy wind speed and plume spreads by sensitive analysis based on the LES data. Our objective is to evaluate the urban-type Gaussian plume model using those representative parameters estimated by sensitive analysis.