湖南工业大学学报2024，Vol.38Issue(5)：10-17,8.DOI:10.3969/j.issn.1673-9833.2024.05.002
微尺度城市冠层模型下的通风与放射性核素扩散特性
Analysis of Ventilation and Radionuclide Diffusion Features Under the Micro-Scale Urban Canopy Layer Model
摘要
Abstract
A research has been carried out on the influence of urban canopy morphology on the migration and diffusion features of radionuclides by using the method of numerical simulation,with an introduction of such four indicators as the velocity ratio(VR),age of air(τp),retention time(τc)and atmospheric dispersion factor(ADF),for an evaluation of the flow and diffusion of radionuclides at pedestrian altitude in urban canopy.The numerical results indicate that changes in urban canopy morphology have a relatively small impact on the air age on the main streets,but have a greater impact on the air age within the street canyons.There is a stronger washing air on the windward side of higher buildings with a better ventilation,while there is airflow stagnation on the leeward side accompanied by a poor ventilation.The migration and diffusion of radioactive isotopes are mainly under the influence of the morphology of urban canopies.Street canyons with a good ventilation may not have a shorter residence time,while poorly ventilated street canyons may not necessarily have a longer residence time.Due to the influence of mechanical turbulence of buildings,the atmospheric dispersion factor is obviously reduced.When the urban canopy shows a protuberant and ascending tendency,the radionuclides are characterized with the best diffusion effect within an area of 450～900 m downstream.关键词
城市冠层形态/放射性核素/速度比/空气龄/滞留时间/大气弥散因子Key words
urban canopy layer morphology/radionuclide/velocity ratio/air age/retention time/atmospheric dispersion factor分类
资源环境引用本文复制引用
高菡,文雅冰,赵福云..微尺度城市冠层模型下的通风与放射性核素扩散特性[J].湖南工业大学学报,2024,38(5):10-17,8.基金项目
国家自然科学基金资助项目(U1867221) （U1867221）
湖南省重点研发计划基金资助项目(2022SK2084) （2022SK2084）
