71 巻 (2015) 4 号 p. I_43-I_48
When simulating the turbulent flow around urban structures with large-eddy simulation models it is often necessary to use non-cyclic boundary conditions in streamwise direction. In such cases a turbulent inflow condition at the inlet is favored although it is highly difficult to obtain. A synthetic turbulence generator, modelling turbulence statistics and correlations, is used to generate a turbulent inflow for large-eddy simulations. Results are compared with simulations using laminar inflow. An artificial urban canopy consisting of aligned buildings with cubical shape was used. Two simulations contained one additional tall building located at the center of the domain. The turbulence statistics show a well-developed urban boundary layer above the building arrays for each simulation. Higher turbulence intensity was found when using the turbulence inflow method resulting in faster development of an urban boundary layer.