Effect of Street Canyon Configurations and Orientations on Urban Wind Velocity in Bangkok Suburb Areas

Abstract

Urban ventilation is considered as one parameter, which impacts on building energy consumption and outdoor living condition. This study primarily investigates the effect of street canyon characteristics as well as its orientations on wind pattern and velocity in street canyon via using urban microclimate simulation model, ENVI-met. The wind simulations are performed with four aspect ratios or height-to-width ratio (H/W), three canyon lengths, and four canyon orientations. Calculated wind velocity measured at 1.5 m height of the centre of the street and pedestrian on both sides of the street ranges from 0.2 to 0.97 m/s. N-S and NW-SE canyons, which oriented parallel to the prevailing wind has greater wind velocity than those oriented perpendicular to the wind. The wind velocity is sensitive to aspect ratio and canyon length. The wind velocity in shallow canyon is mostly higher than those in the deep canyon. However, increasing the canyon length considerably improves the low wind speed in the deep canyon up to twice.