The effects of thermal stratification on airborne transport within the urban roughness sublayer
文献类型：期刊论文
| 作者 | Cai, Junjie1; Chen, Jingtan1; Cheng, Haimei2; Zi, Shuangfei2; Xiao, Jinchao2; Xia, Fan1,3,4; Zhao, Jiyun1 |
| 刊名 | INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
 |
| 出版日期 | 2022-03-01 |
| 卷号 | 184 |
| 关键词 | Thermal stratification Atmospheric dispersion Urban roughness sublayer (RSL) Computational fluid dynamics (CFD) Scalar fluxes Transfer coefficients |
| ISSN号 | 0017-9310 |
| DOI | 10.1016/j.ijheatmasstransfer.2021.122289 |
| 通讯作者 | Zhao, Jiyun(jiyuzhao@cityu.edu.hk) |
| 英文摘要 | The release of airborne hazardous substances in the urban roughness sublayer (RSL) is a risk to human health. The atmospheric dispersion of these materials should be contained to mitigate their adverse consequences. This study investigates the effects of atmospheric stability on the air, heat, and pollutant transport within RSL by a validated 3-D RANS code. A building morphology with height variance is proposed for better representing the real urban environment and characterizing the complex interactions between the roughness elements and the flow regimes. The thermal stratification stability test subject to the ground-inflow temperature difference is extended to span from strongly unstable to moderately stable. The quantitative indicators, including air exchange rate, heat removal rate, pollutant removal rate, heat transfer coefficient, and pollutant transfer coefficient, are introduced and analyzed. The correlations between indicators and thermal stabilities are established, which provides explicit expressions to describe the influence of the changing bulk Richardson number (Rb). Results show that the design of height variance elements enables a stronger lateral momentum towards the target street canyon, which suppresses the spanwise dispersion of pollutants. The discussions upon heat and pollutant transport based on stability categories show a high Rb-dependence of heat/mass transfer efficiency. The stability threshold is demonstrated to be Rb approximate to 0.7, where the flow speed near the ground approaches zero. As a result, the high temperature gradient is formed and acts as positive feedback to facilitate a more stratified condition. The accurate and rational correlations obtained in this study will save the computational cost considerably for further research. Also, the available results will be a reference for environmentally friendly designs. (c) 2021 Elsevier Ltd. All rights reserved. |
| WOS关键词 | FIELD POLLUTANT DISPERSION ; LARGE-EDDY SIMULATION ; WIND-TUNNEL MEASUREMENTS ; STREET CANYONS ; TURBULENT-FLOW ; NUMERICAL INVESTIGATIONS ; ATMOSPHERIC DISPERSION ; CITY BREATHABILITY ; CFD SIMULATIONS ; RE-INDEPENDENCE |
| 资助项目 | Guangzhou Science & Technology and Innovation Commission[201907010007] |
| WOS研究方向 | Thermodynamics ; Engineering ; Mechanics |
| 语种 | 英语 |
| WOS记录号 | WOS:000755378200002 |
| 出版者 | PERGAMON-ELSEVIER SCIENCE LTD |
| 资助机构 | Guangzhou Science & Technology and Innovation Commission |
| 源URL | [http://ir.hfcas.ac.cn:8080/handle/334002/127772]  |
| 专题 | 中国科学院合肥物质科学研究院 |
| 通讯作者 | Zhao, Jiyun |
| 作者单位 | 1.City Univ Hong Kong, Dept Mech Engn, Hong Kong, Peoples R China 2.Chinese Acad Sci, Shenyang Inst Automat Guangzhou, Guangzhou 511458, Peoples R China 3.Chinese Acad Sci, Inst Nucl Energy Safety Technol, Hefei Inst Phys Sci, Key Lab Neutron & Radiat Safety, Hefei 230031, Peoples R China 4.Univ Sci & Technol China, Hefei 230026, Peoples R China |
| 推荐引用方式 GB/T 7714 | Cai, Junjie,Chen, Jingtan,Cheng, Haimei,et al. The effects of thermal stratification on airborne transport within the urban roughness sublayer[J]. INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER,2022,184. |
| APA | Cai, Junjie.,Chen, Jingtan.,Cheng, Haimei.,Zi, Shuangfei.,Xiao, Jinchao.,...&Zhao, Jiyun.(2022).The effects of thermal stratification on airborne transport within the urban roughness sublayer.INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER,184. |
| MLA | Cai, Junjie,et al."The effects of thermal stratification on airborne transport within the urban roughness sublayer".INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER 184(2022). |
入库方式： OAI收割
来源：合肥物质科学研究院
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。