Numerical simulation of atmosphere flow considering obstruction over terrain using general coordinate IBM

Abstract

Simulation of turbulent air flow over terrain influenced by objects like buildings is done using terrain fitting curvilinear coordinate system with obstacles represented by the Immersed Boundary Method (IBM). With a slight increase in computational efforts compared with the commonly used IBM on rectangular grids, the properties of the ground boundary layer and the effects of the disturbances by the obstacles can efficiently be represented in Large Eddy Simulation (LES) of the local wind field. The detailes of the technique are explained and an application to a real terrain in Toyama prefecture of Japan is presented. Though the Reynolds number used in these demonstrations is relatively low, the results are good and encourage further development to full scale flows.