1.Hunan University of Science and Technology;2.Hunan Univerisity of Science and Technology
Natural Science Foundation of China(No.51308206, 51474105), International Science and Techonology Cooperation Program of China(No.2014DFA72190)，Hunan Provincial Innovation Foundation For Postgraduate (CX20190799)
自然通风能够有效的降低室内污染物浓度，包括稀释生物气溶胶浓度。穿堂风是其主要形式之一。但在人口稠密的城市，建筑之间的遮挡作用会明显降低通风效果。在之前的研究中，鲜见讨论建筑孔洞特性对其他建筑的影响。作为初步研究，本文以两栋建筑为研究对象，讨论上游建筑的9种情形——不同的开窗面积与位置，对下游建筑穿堂风潜力的影响。本文仅讨论一个来流方向，而且此两栋建筑中心线在位于这个来流方向的直线上，间距为两倍建筑宽度。文章首先分析基于稳态RANS模型（Reynolds-averaged Navier–Stokes）的CFD（Computational Fluid Dynamics）模拟风压的可靠性。结果显示，部分情形的CFD模拟的可靠性不高。相对于上游建筑5%与10%的孔隙率，20％的孔隙率难以通过CFD模拟出下游建筑物的风压。然而，风洞实验数据显示，下游建筑物的穿堂风通风潜力随上游建筑物开窗面积的增加而降低，这与一般观点相反。
Natural ventilation can effectively reduce indoor pollutant concentrations, including dilution of biological aerosol concentrations. Cross ventilation is one of its main forms. However, in dense cities, the shielding effect between buildings will significantly reduce the ventilation effect. In previous studies, it is rare to discuss the effects of building hollow characteristics on other buildings. As a preliminary study, this article takes two buildings as the research object, and discusses the nine situations of upstream buildings—different window area and position, and their influence on the cross ventilation potential. This article discusses only one direction of incoming flow where the two buildings locates in a line for twice building width. The paper first analyses the reliability of Computational Fluid Dynamics(CFD) simulation based on steady Reynolds-averaged Navier–Stokes(RANS). The results reveal that the reliability of CFD simulation in some cases is insufficient that with a simulation of 20 % porosity it is hard to reproduce the wind pressure on a downstream building by CFD in comparison to 10 % or 5 % porosity. The different simulation reliability may be caused by the instability of airflow between buildings. However, by data from the wind tunnel, we found that the cross ventilation potential of the downstream building decreases with the increase of the window area of the upstream building, which is contrary to general beliefs.