单体1:1:6方形截面建筑绕流的大涡模拟

Large eddy simulation of flow around a single square building model with 1:1:6 shape

基于Fluent 6软件平台,采用大涡模拟(LES)方法对一宽高比为1:1:6的高层建筑缩尺模型表面的平均和脉动风压进行了数值模拟,并与相应风洞试验结果进行了比较和分析,然后,研究了不同来流湍流度对结构表面风压分布的影响。结果表明:(1)对于类似研究的0°风向角下的方形截面建筑来说,结构迎风面风压直接受来流湍流的影响;侧面由于存在流动分离,其风压主要受分离产生的特征湍流的影响,受来流湍流度的影响较小;而背风面处于复杂的尾流区,其表面风压受到的影响因素比较复杂。(2)在风压系数的统计特性和自谱上,LES结果与风洞试验结果均能够基本保持一致,LES方法能够较准确预测结构表面的平均和脉动风压分布。

Based on Fluent 6,the mean and fluctuating wind pressure coefficients of a high-rise building scaled model with aspect ratio of 1：1：6 were numerically simulated by adopting large eddy simulation（LES）.The simulated results were firstly compared with those of wind tunnel tests.Then,the effect of incoming flow turbulent intensity on the wind pressure distribution on the structure was investigated.The results showed that（1） For similar structures,the wind pressure on the windward face is directly affected by oncoming flow turbulence,while the lateral faces are almost not affected but mainly affected by the signature turbulence caused by the flow separation;for the reason that the leeward face is located in the wake of the flow,the factors influencing wind pressure on the leeward face are relatively complex;（2） the statistic characteristics and the spectra of the wind pressure coefficients for LES results are elementarily in accordance with those of wind tunnel test results;LES technique can precisely predict the mean and fluctuating wind pressure distributions on surface of structures.