自然风主导城市街谷放射性污染物扩散特性模拟  

Simulation of diffusion characteristics of radioactive pollutants in urban street canyons dominated by natural wind

作　　者：赵福云[1] 尚瑨 景一 仲怀玉 刘娣 王汉青 ZHAO Fuyun;SHANG Jin;JING Yi;ZHONG Huaiyu;LIU Di;WANG Hanqing(School of Power and Mechanical Engineering,Wuhan University,Wuhan 430072,China;College of Pipeline and Civil Engineering,China University of Petroleum,Qingdao 266580,China;Central South University of Forestry Science and Technology,Changsha 410004,China)

机构地区：[1]武汉大学动力与机械学院,湖北武汉430072 [2]中国石油大学(华东)储运与建筑工程学院,山东青岛266580 [3]中南林业科技大学,湖南长沙410004

出　　处：《武汉大学学报（工学版）》2022年第6期623-631,共9页Engineering Journal of Wuhan University

基　　金：国家自然科学基金核工业联合基金项目(编号:U1867221);中央高校基本科研业务费专项资金资助项目(编号:2042020kf0203);国家自然科学基金面上项目(编号:51778504)。

摘　　要：为研究城市街道峡谷中放射性污染物的扩散特性问题,采用计算流体力学(computational fluid dynamics,CFD)模拟方法,以理想城市建筑群为例,分析2个主要几何因素对污染物扩散的影响:1)建筑物高宽比(H/W);2)城市形态。结果显示,建筑高宽比和城市建筑形态对污染物的扩散影响较大,H/W=1时,城市体积内污染物浓度最低,约为290 Bq/m^(3);H/W=2时污染物浓度最高,约为390 Bq/m^(3)。第1列建筑的高度变化会改变城市冠层上方的空气流动结构,对街谷内污染物浓度产生较大的影响。在6种不同类型的城市建筑群中,下降型建筑群和凹形建筑群的街谷内平均污染物浓度明显低于其他类型,约为260 Bq/m^(3)。研究结果表明,合理的建筑布置可以改善街区污染物滞留情况,为存在放射性污染物下的城市形态结构优化设计提供理论依据。In order to study the diffusion characteristics of radioactive pollutants in urban street canyons,the diffusion characteristics of radioactive pollutants in 6 ideal urban building complexes are studied by CFD method.The influences of two main geometric factors on the diffusion of pollutants are considered:1)aspect ratio of buildings;2)urban morphology.The results show that the two factors have great influences on the pollutant diffusion.When H/W=1,the pollutant concentration in urban volume is the lowest,about 290 Bq/m^(3);when H/W=2,the pollutant concentration is the highest,about 390 Bq/m^(3).The height changing of the first building will change the air flow structure above the urban canopy,and have a great impact on the pollutant concentration in the downstream street canyons.In the six different types of urban morphology,the average pollutant concentration in the street canyon of the descending and concave building group is significantly lower than that of other types,which is about 260 Bq/m^(3).The results show that reasonable building layout can reduce the pollutant retention in the street canyons.The research can provide a theoretical basis for the optimization ventilation design of urban morphology and structure in the presence of radioactive pollutants.

关 键 词：城市通风 计算流体力学 放射性污染物扩散 街区峡谷通风 

分 类 号：X169[环境科学与工程—环境科学]