基于一种标准城市建筑模型的行人高度风环境比较研究

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

摘要:

对日本建筑学会（AIJ）提出的标准建筑风环境模型，分别采用风洞试验、基于雷诺平均（RANS）和大涡模拟（LES）的数值模拟方法，开展了考虑不同中央高层建筑高度和来流风向角对周围行人高度风环境影响的详细比较研究。结果表明：RANS和LES模拟得到各测点风速比的变化趋势与风洞试验整体上一致，相对而言，LES模拟结果与风洞试验结果更接近，平均误差约为RANS的1/2；而RANS方法总体上低估了行人高度风速，无法准确反映建筑背风面的风加速状况。随着中央建筑高度的增加，周边行人高度风速逐渐增大，100 m高度的超高层建筑对局部区域风速的加速达到1.6倍；但当中央建筑高度超过150 m、继续增大至200 m时，行人高度风速不再增大。当风向角在0°~90°范围变化时，在高层建筑背风面和角区附近会产生行人高度风场加速的“文丘里效应”；其中当来流风向角为45°时，风加速情况最为显著，显示出斜风来流工况下会对高层建筑周边行人风环境带来最不利的影响。

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.