Evaluating different categories of turbulence models for calculating air pollutant dispersion in street canyons with generic and real urban layouts

IF 4.2 2区工程技术 Q1 ENGINEERING, CIVIL

Journal of Wind Engineering and Industrial Aerodynamics Pub Date : 2024-11-16 DOI:10.1016/j.jweia.2024.105948

Jue Wang, Ruoyu You

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引用次数: 0

Abstract

Turbulence models are crucial for simulating urban pollutant dispersion by computational fluid dynamics (CFD) methods. This study aimed to evaluate the performance of steady-state and unsteady-state Reynolds-averaged Navier-Stokes simulation (SRANS/URANS) and large-eddy simulation (LES) in calculating air pollutant dispersion in street canyons with generic and real urban layouts. For each layout, wind tunnel experiments with measured wind speed and pollutant concentration were available as benchmarks. In addition, instantaneous concentration fields were analyzed to assess the transient models. The results showed that in both generic and real urban layouts, the RNG

k - ε

model and SST

k - ω

model provided similar results for time-averaged wind speed and concentration distributions in SRANS and URANS simulations. LES performed the best in calculating wind speed and pollutant dispersion. In a generic urban layout, URANS with the SST

k - ω

model captured large-scale fluctuations, while instantaneous results from URANS with the SST

k - ω

model did not change over time in a real urban layout. SRANS/URANS with the SST

k - ω

model can provide acceptable results for time-averaged pollutant concentration fields in a generic urban layout with simple building shapes and placements. However, for real urban layouts, the LES approach is the most accurate way to calculate air pollutant dispersion.

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评估不同类别的湍流模型，以计算一般和实际城市布局中街道峡谷的空气污染物扩散情况

湍流模型是利用计算流体动力学（CFD）方法模拟城市污染物扩散的关键。本研究旨在评估稳态和非稳态雷诺平均纳维-斯托克斯模拟（SRANS/URANS）和大涡模拟（LES）在计算一般和实际城市布局的街道峡谷中空气污染物扩散时的性能。对于每种布局，都有测量风速和污染物浓度的风洞实验作为基准。此外，还对瞬时浓度场进行了分析，以评估瞬态模型。结果表明，在一般和实际城市布局中，RNG k-ε 模型和 SST k-ω 模型在 SRANS 和 URANS 模拟中提供了相似的时间平均风速和浓度分布结果。LES 在计算风速和污染物扩散方面表现最佳。在一般城市布局中，采用 SST k-ω 模型的 URANS 能够捕捉到大尺度波动，而在实际城市布局中，采用 SST k-ω 模型的 URANS 的瞬时结果不会随时间变化。采用 SST k-ω 模型的 SRANS/URANS 可以为具有简单建筑形状和位置的一般城市布局中的时间平均污染物浓度场提供可接受的结果。然而，对于真实的城市布局，LES 方法是计算空气污染物扩散的最准确方法。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Wind Engineering and Industrial Aerodynamics 工程技术-工程：土木

CiteScore

8.90

自引率

22.90%

发文量

306

审稿时长

4.4 months

期刊介绍： The objective of the journal is to provide a means for the publication and interchange of information, on an international basis, on all those aspects of wind engineering that are included in the activities of the International Association for Wind Engineering http://www.iawe.org/. These are: social and economic impact of wind effects; wind characteristics and structure, local wind environments, wind loads and structural response, diffusion, pollutant dispersion and matter transport, wind effects on building heat loss and ventilation, wind effects on transport systems, aerodynamic aspects of wind energy generation, and codification of wind effects. Papers on these subjects describing full-scale measurements, wind-tunnel simulation studies, computational or theoretical methods are published, as well as papers dealing with the development of techniques and apparatus for wind engineering experiments.