Investigation of convective heat transfer at the facade with balconies for a multi-story building
Investigation of convective heat transfer at the facade with balconies for a multi-story building
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DOI：
10.1016/j.jobe.2022.105420
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发表时间：
2022-11
影响因子：
6.4
通讯作者：
Shi Tao;Nanyang Yu;Zhengtao Ai;K. Zhao;Fujian Jiang
中科院分区：
文献类型：
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作者：
Shi Tao;Nanyang Yu;Zhengtao Ai;K. Zhao;Fujian Jiang
阳台作为一种常见的建筑附着物，会显著改变建筑外墙附近的流态，从而对外墙的对流换热系数产生很大影响。本文采用三维定常雷诺平均纳维-斯托克斯(RANS)SSTK-ω模型对带阳台建筑立面的对流换热进行了计算流体力学模拟。通过小尺度风洞实验对该模型进行了系统验证，并利用高分辨率网格进行了数值模拟。详细分析了阳台高度(阳台女儿墙高度)、阳台深度和阳台长度对立面和阳台表面强制对流换热的影响。结果表明，阳台的存在使迎风立面的地表平均CHTC(CHTCavg)降低了17.5%，而背风立面的CHTC(CHTCavg)降低了35.2%。此外，当阳台高度(HP)从0.5到1.5米变化时，背风立面、迎风阳台和背风阳台内表面的CHTCavg分别下降了39%、48.8%和50%。然而，阳台深度和长度对建筑立面和阳台表面的CHTCavg影响相对不显著。最后，建立了新的关联式来描述立面和阳台表面的平均CHTC。由关联式和模拟法得到的CHTCavgogo值相差不到6%。本研究的结果将有助于计算带阳台的建筑物的冷负荷和热负荷。
As a common building appendage, balconies can significantly alter the flow pattern near the building façade, thus greatly affecting the convective heat transfer coefficient (CHTC) of façades. In the present study, computational fluid dynamics (CFD) simulations are performed with the 3D steady Reynolds-averaged Navier-Stokes (RANS) SSTk-ωmodel to evaluate the convective heat transfer at the building façade with balconies. This model is systematically validated by a reduced-scale wind tunnel experiment and then utilized to conduct simulations with high-resolution grids. The effects of the balcony height (height of balcony parapet walls), depth, and length on the forced convective heat exchange at the façade and balcony surfaces are analyzed in detail. The results show that with the presence of balconies, the surface-averaged CHTC (CHTCavg) is reduced by about 17.5% at the windward facade, while it is reduced by 35.2% at the leeward façade. Furthermore, when the height of the balcony (Hp) varies from 0.5 to 1.5 m, CHTCavgdecreases by up to 39%, 48.8%, and 50% on the leeward facade, the inner surfaces of windward and leeward balconies, respectively. However, balcony depth and length have relatively non-significant effects on the CHTCavgof building facades and balconies' surfaces. Finally, new correlations are established to describe the average CHTC along the façade and balconies’ surfaces. The difference in CHTCavgobtained from the correlations and the simulations is less than 6%. The findings of the present study would facilitate the calculation of the cooling and heating loads of buildings with balconies.