Field Measurements and CFD Analyses on the Effects of Moving Automobiles on Airflow and Turbulent Diffusion in Street Canyons

Abstract

The aim of this study is to develop a simulation method to predict the turbulent diffusion process and the thermal environment, which are affected by various small obstacles, within the real situation of urban street canyons based on the methodology of canopy models. This study extends the previous researches of canopy models conducted by the present authors to reproduce the effects generated from various small obstacles, including moving objects such as automobiles, in actual urban space. Three test cases of computations were carried out by using the new developed 'Vehicle Canopy Model'. In the cases without automobiles, k values were largely underpredicted, but the prediction accuracy of k values was greatly improved in the case with moving automobiles.