Effect of fluctuating wind direction on cross natural ventilation in buildings from large eddy simulation

A large eddy simulation (LES) program with the Smagorinsky subgrid-scale model has been used to study cross natural ventilation in buildings, which has experimental data available from on-site measurements and a wind tunnel. Since natural wind changes direction over time, it is hard to reproduce this effect in a conventional wind tunnel where the "wind" direction is fixed. There are discrepancies between the on-site and wind-tunnel cases for the wind-pressure difference across the buildings, the eddy size behind the buildings, and the wind speed distribution inside an apartment with cross ventilation. LES can successfully simulate both cases by changing or fixing incoming wind direction, and the simulated results agree reasonably with the corresponding experimental data. (C) 2002 Elsevier Science Ltd. All rights reserved.