Effects of Trees on Pedestrian Wind Comfort in an Urban Area Using a CFD model

This study investigated the effects of trees on the pedestrian wind comfort in the Pukyong National University (PKNU) campus. For this, we implemented the tree’s drag parameterization scheme to a computational fluid dynamics (CFD) model and validated the simulated results against a field measurement. The CFD model well reproduced the measured wind speeds and TKEs in the downwind region of the trees, indicating successful implementation of the tree drag parameterization schemes. Besides, we compared the wind speeds, wind directions, and temperatures simulated by the CFD model coupled to the local data assimilation and prediction system (LDAPS), one of the numerical weather prediction models operated by the Korean Meteorological Administration (KMA) to those observed at the automated weather station (AWS). We performed the simulations for one week (00 UTC 2 – 23 UTC 9 August 2015). The LDAPS overestimated the observed wind speeds (RMSE = 1.81 m s^–1), and the CFD model markedly improved the wind speed RMSE (1.16 m s^–1). We applied the CFD model to the simulations of the trees' effects on pedestrian wind comfort in the PKNU campus in views of wind comfort criteria based on the Beaufort wind force scale (BWS). We will present the trees' effects on pedestrian wind comfort in the PKNU campus in detail.