Numerical evaluation of pollutant dispersion in the built environment: Comparisons between models and experiments
Numerical evaluation of pollutant dispersion in the built environment: Comparisons between models and experiments
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DOI：
10.1016/j.jweia.2008.02.049
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发表时间：
2008-10-01
影响因子：
4.8
通讯作者：
Wang, X.
中科院分区：
文献类型：
--
作者：
Blocken, B.;Stathopoulos, T.;Wang, X.
采用商用程序Fluent 6.1对中性稳定大气边界层中的污染物扩散进行了稳态RANS计算流体动力学（CFD）模拟，并对三个案例进行了研究：孤立烟囱的烟羽扩散、孤立立方体建筑模型屋顶通风口的低动量排气和带有几个屋顶结构的低层矩形建筑屋顶烟囱的高动量排气。将计算结果与高斯模型、半经验ASHRAE模型、风洞和全尺寸测量结果进行了比较。结果表明，在所有三种情况下，所有的湍流模型测试，横向羽流蔓延显着低估。有人建议，瞬态模拟可能需要实现更准确的结果。数值结果对湍流施密特数的取值相当敏感。然而，由于模拟中存在大量其他误差源，包括稳态RANS模型、湍流模型、近壁处理限制和湍流动能剖面中的非预期流向梯度，因此比较无法清楚地表明哪种施密特数最适合哪种类型的流动。(c)2008爱思唯尔有限公司保留所有权利。
Steady-state RANS Computational Fluid Dynamics (CFD) simulations of pollutant dispersion in the neutrally stable atmospheric boundary layer are made with the commercial code Fluent 6.1 for three case studies: plume dispersion from an isolated stack, low-momentum exhaust from a rooftop vent on an isolated cubic building model and high-momentum exhaust from a rooftop stack oil a low-rise rectangular building with several rooftop structures. The results are compared with the Gaussian model, the semi-empirical ASHRAE model and wind tunnel and full-scale measurements. It is shown that in all three cases and with all turbulence models tested, the lateral plume spread is significantly underestimated. It is suggested that transient simulations might be required to achieve more accurate results. The numerical results are quite sensitive to the value of the turbulent Schmidt number. The comparisons however cannot clearly indicate which Schmidt number is most suitable for which type of flow due to the large number of other error sources ill the simulations, including steady-state RANS modelling, turbulence modelling, near-wall treatment limitations and unintended streamwise gradients in the turbulent kinetic energy profiles. (c) 2008 Elsevier Ltd. All rights reserved.