双坡屋面低矮房屋风致内压的数值模拟

针对围护结构出现洞口后风致内压与外压联合作用这一造成建筑物严重破坏的主要原因,应用计算流体力学软件ANSYS Fluent 12.0,选用基于Reynolds时均的标准k-ε湍流模型,对低矮房屋单一主洞口及多洞口模型进行不同工况的数值模拟分析.结果表明:单一洞口工况下开孔率对风致内压影响很小,而开洞位置对各表面风致内压分布的影响显著;多洞口工况0°风向角时,平均内风压系数随着洞口面积比的增大而增大,但增大趋势逐渐变缓;纵墙和屋面同时开洞且开洞面积比一定时,结构平均内风压系数随风向角变化显著,且内压分布的不均匀性显著增强.

Numerical Simulation of Wind-Induced Internal Pressure on Gable Roof Low-Rise Buildings

The main damages of buildings in gale occurred by the combined effect of external pressure and wind-induced internal pressure which is caused by the sudden openings on structure surfaces.A standard k-ε model,the Reynolds Averaged Navier-Stokes Equations(RANS) turbulence model,was adopted to numerically simulate different cases of low-rise buildings with one main opening or multi-openings with fluid dynamics software ANSYS Fluent 12.0.The analysis results show that,for single dominant opening cases,the opening ratios doesn′t affect the wind-induced internal pressure,while the opening′ locations affect both the magnitude and distribution of wind-induced internal pressures;for multi-openings cases at 0°wind attack angle,the mean internal pressure coefficients increase with increasing the opening ratio,but the trend of increase gradually slows down;at a certain ratio of AW/AL,the mean internal pressure is affected significantly by the wind attack angle,and the inhomogeneity of internal pressure enhances markedly.