A Comparative Study of Pedestrian-Level Wind Environment Based on a Standard Urban Building Model

Abstract:

A detailed comparative study was conducted to investigate the influence of different heights of central high-rise building and wind incident angles on the surrounding pedestrian-level wind environment by means of the wind tunnel test， Reynolds-averaged Navier-Stokes （RANS） and large-eddy simulation （LES） simulations simutaneously based on a standard urban building model proposed by AIJ （Architectural Institute of Japan）. The results show that the overall distributions of the wind speed ratio at the measuring points obtained from the RANS and LES simulations respectively are both consistent well with the wind tunnel test data， while the LES results are relatively better， which is reflected by the average error of LES being only half of that the RANS. Generally， the RANS simulation underestimates the pedestrian-level wind speed to some extent， especially it cannot appropriately reflect the wind acceleration phenomenon on the leewards of the building. The pedestrian-level wind speed is positively related with the height of the central building， and the building height over 100m will accelerate the pedestrian-level wind speed apparently by 1.6 times. However， as the height of the central building exceeds 150m （till 200m） ， the pedestrian-level wind speed will not increase further. As the wind incident angle varies from 0° to 90°， the so-called Venturi effect phenomenon will occur in the leewards and the corners of the central high-rise building. The pedestrian-level wind speed will accelerate to its highest level when the incident angle reaches 45°， which indicates that the oblique incident wind is the most unfavorable condition for considering the pedestrian-level wind environment situation around the high-rise building.

Key words:high-rise building;pedestrian-level wind environment;wind tunnel experiment;Reynolds-averaged Navier-Stokes (RANS);large-eddy simulation (LES)