【摘要】 在不利气象条件下建筑屋顶烟囱排放污染物对近地面空气质量影响较大，因此对其扩散特性进行评估至关重要。采用数值模拟方法，研究不同风向（风向角α=0°～180°）下，下台阶建筑屋顶烟囱排放污染物扩散分布特性；采用商业软件FLUENT对基于standard k-ε湍流模型的数值模型进行求解。结果表明：烟囱排放污染物对近地面空气质量的影响受风向角影响较大，这会导致建筑背风面上污染物浓度分布不一致，尤其是α=0°时，对建筑壁面以及街谷内的行人呼吸高度处影响最大。更多还原

【Abstract】 Under the adverse weather conditions, the pollutants released from the building rooftop stack have a great impact on the near-field air quality. It is critical to evaluate their diffusion characteristics. Numerical simulation was used to study the diffusion and distribution characteristics of pollutants discharged from the rooftop of the low-rise building under the wind direction α of 0°～180°. The convection-diffusion equations were solved by standard k-ε turbulence model in the commercial software FLUENT. Results show that the air quality near the ground is greatly affected by the wind direction, which results in the inconsistent concentration distribution on the building leeward side. Especially at α = 0°, the largest impact is observed on the building walls and the pedestrian breathing height plane in the street canyon.更多还原