The recirculation flow after different cross-section shaped high-rise buildings with applications to ventilation assessment and drag parameterization

作     者：Keyi Chen Ziwei Mo Jian Hang Keyi Chen;Ziwei Mo;Jian Hang

作者机构：School of Atmospheric SciencesSun Yat-sen University&Southern Marine Science and Engineering Guangdong LaboratoryZhuhai519082China Key Laboratory of Tropical Atmosphere-Ocean SystemMinistry of EducationZhuhai519000China 

出 版 物：《Building Simulation》 (建筑模拟（英文）)

年 卷 期：2024年第17卷第4期

页      面：509-524页

核心收录：

学科分类：080704[工学-流体机械及工程] 080103[工学-流体力学] 08[工学] 0807[工学-动力工程及工程热物理] 0801[工学-力学（可授工学、理学学位）] 

基　　金：This work was supported by the National Natural Science Foundation of China—Youth Science Foundation Project No.42205073 Guangdong Basic and Applied Basic Research Foundation No.2021A1515110182 Guangdong Natural Science Fund No.2023A1515012863 the Innovation Group Project of the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)No.311020001 

主　　题：recirculation region cross-section shape ventilation assessment drag parameterization computational fluid dynamics 

摘      要：The building cross-section shape significantly affects the flow characteristics around buildings,especially the recirculation region behind the high-rise *** generic building shapes including square,triangle,octagon,T-shaped,cross-shaped,#-shaped,H-shaped and L-shaped are examined to elucidate their effects on the flow patterns,recirculation length L and areas A using computational fluid dynamics(CFD)simulations with Reynolds-averaged Navier-Stokes(RANS)*** sizes and positions of the vortexes behind the buildings are found to be substantially affected by the building shapes and subsequently changing the recirculation *** recirculation length L is in the range of 1.6b-2.6b with an average of *** maximum L is found for L-shaped building(2.6b)while the shortest behind octagon building(1.6b).The vertical recirculation area Av is in the range of 1.5b^(2)-3.2b^(2)and horizontal area Ah in 0.9b^(2)-2.2b^(2).The L,Av and Ah generally increase with increasing approaching frontal area when the wind direction changes but subject to the dent structures of the#-shaped and cross-shaped *** area-averaged wind velocity ratio(AVR),which is proposed to assess the ventilation performance,is in the range of 0.05 and 0.14,which is around a three-fold difference among the different building *** drag coefficient parameterized by Ah varies significantly,suggesting that previous models without accounting for building shape effect could result in large uncertainty in the drag *** findings provide important reference for improving pedestrian wind environment and shed some light on refining the urban canopy parameterization by considering the building shape effect.