An Approach for quantitative forecasting of turbulent flow over an urban area by coupling numerical weather prediction and Large-Eddy Simulation models

Takemi, Tetsuya*; Nakayama, Hiromasa   

Atmospheric flows in urban areas are highly turbulent owing not only to meteorological disturbances but also to complex and complicated distribution of roughness obstacles (i.e., buildings). Numerical modeling is an important research for this purpose. In order to numerically examine flows over such highly rough urban surfaces, a large-eddy simulation (LES) approach is promising. In order to ensure the turbulent nature of flows in urban areas, an LES approach with a proper turbulence-generation technique is necessary. The present study proposes an approach to quantitatively simulate turbulent flows in a densely-built environment with the mixture of high-rise and low-rise buildings by coupling the WRF model and an LES model.