CFD simulations of near-field pollutant dispersion with different plume buoyancies
CFD simulations of near-field pollutant dispersion with different plume buoyancies
复制标题
DOI：
10.1016/j.buildenv.2018.01.008
复制
发表时间：
2018-03-01
影响因子：
7.4
通讯作者：
Stathopoulos, Ted
中科院分区：
文献类型：
--
作者：
Tominaga, Yoshihide;Stathopoulos, Ted
本研究对孤立的立方体建筑模型周围的流动和分散场进行计算流体动力学模拟，示踪气体从建筑物后面的出口排出。根据与环境空气的密度差异，示踪气体具有三种不同的浮力，因此表现为中性、轻质和重质气体。本文通过将模拟结果与不同羽流浮力的实验结果进行比较，检查了使用 Boussinesq 近似的稳定雷诺平均纳维斯托克斯 (BANS) 模拟的性能。即使重气体的模型性能优于轻气体且差于中性气体，稳定的 RANS 计算通常可以在实验结果中重现羽流浮力对平均浓度的影响。这种趋势与建筑物背后的平均速度和湍流动能的预测精度密切相关，而该精度受到稳态BANS模拟的限制。研究还证实，epsilon 方程中的浮力模型对结果的影响可以忽略不计。
This study performs computational fluid dynamics simulations for flow and dispersion fields around an isolated cubic building model with tracer gases being exhausted from an exit behind the building. The tracer gases have three different buoyancies according to the difference in density with ambient air and, therefore, behave as neutral, light, and heavy gases. The performance of steady Reynolds-averaged Navier Stokes (BANS) simulations with the Boussinesq approximation is examined herein by comparing the simulation results with the experimental results for different plume buoyancies. The steady RANS computations can generally reproduce the impact of plume buoyancy on the mean concentration in the experimental results even if the model performance for heavy gases is better than that for light gases and worse than that for neutral gases. This tendency is closely related to the prediction accuracy of the mean velocity and turbulent kinetic energy behind the building, which is restricted by the steady BANS simulations. The study also confirmed that the buoyancy modeling in the epsilon equation shows a negligible influence on the results.