Large eddy simulation of flow past cubic obstacles

Large eddy simulation of flow past rectangular arrays of cubic obstacles was performed, and the results were compared to wind tunnel data. The motivation for the study was to investigate the flow dynamics within the urban canopy and evaluate the use of LES in such applications, assuming that the obstacle arrays can represent a simplified urban environment. Mean velocity profiles were compared at selected locations, including the recirculating regions downstream of obstacles and the gap regions between laterally adjacent obstacles. The spatially-varying nature of the urban canopy flow is discussed. Large eddy simulation shows promise in accurately simulating the flow features within the urban canopy, but a number of issues stand in the way of its operational use. Some of the outstanding issues, such as surface boundary conditions and the inlet condition, are addressed.