基于流场验证的紊流施密特数对街道峡谷污染物扩散数值模拟的影响  

Effects of Turbulence Schmidt Number on the Pollutant Diffusion Simulation in a Street Canyon Based on Numerical Flow and Concentration Fields Validations

作　　者：谢海英[1] 关欣[1] 沐贤维 李晓 温雅 XIE Haiying;GUAN Xin;MU Xianwei;LI Xiao;WEN Ya(School of Environment and Architecture,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学环境与建筑学院,上海200093

出　　处：《上海理工大学学报》2018年第5期466-474,共9页Journal of University of Shanghai For Science and Technology

基　　金：2017年度上海市级大学生创新创业训练计划(SH2017105)

摘　　要：以城市街道峡谷的水槽和风洞试验数据为依据,利用ANSYS Fluent软件,数值模拟了街道峡谷内的流场(包括时均流动和紊流强度)及污染物浓度。结果表明:标准k-ε紊流模型、RNG k-ε紊流模型和标准k-ω紊流模型均能基本正确地模拟街道峡谷内的流场和浓度场;紊流施密特数Sct对浓度值有明显的影响,街道峡谷内的浓度值随Sct的增加而变大,当Sct取1.3时,浓度值和试验值吻合最好;由于标准k-ω模型对流场的模拟结果相对最好,其模拟的浓度场也与试验值吻合最佳。街道峡谷内的浓度分布由时均流输运和紊流扩散共同决定,因此,合理的Sct数不能仅仅依据浓度值与试验值的吻合度来选取,而应首先保证流动模拟的准确性。Based on numerical flow field and pollutant concentration field validations,three turbulence models(standard k-εmodel,RNG k-εmodel,standard k-ωmodel)were chosen to study Sct(turbulence Schmidt number)effects on the pollutant diffusion simulation in a street canyon using ANSYS Fluent software.The results show that the three turbulence models all perform well in simulating the flow and concentration fields.The concentration values change significantly with Sct and the optimum Sct value is 1.3 by which the best agreement can be got between the concentration field results and the wind tunnel experimental data.Because of the accurate prediction of the flow field with the standard k-ωmodel,the corresponding concentration results are also closer to the experiment data than those by the other two turbulence models.The optimum Sct value should be determined not only by the validation of concentration field but also by the validation of flow field.

关 键 词：街道峡谷 紊流施密特数 流场 浓度场 数值模拟 

分 类 号：X169[环境科学与工程—环境科学]