下台阶建筑屋顶烟肉排放污染物扩散特性研究

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中图分类号： X511 文献标志码：A

Abstract： Based on a numerical model validated by wind tunnel experiments， the influence of atmospheric stability， characterized by the bulk Richardson number （Rib） in the range of -0.21 to 0.79， on the diffusion of pollutants from roof chimneys on step-down buildings was investigated. The results indicate that the flow field and pollutant distribution within the street canyon are significantly altered by atmospheric stability.Under stable conditions （Rib>0） ）， vertical convection within the street canyon was weak. At Rib=0.43 ， the dimensionless velocity difference （O.25） on the vertical center plane （y/H=0） was reduced by 13.80% compared to that under neutral conditions. At Rib=0.79 ， the maximum dimensionless concentration （4.76） at the pedestrian breathing level was increased by 18.70% . Under unstable conditions （Rib<0） ，vertical convection was enhanced， with increased wind speed near the ground， leading to a notable decrease in pollutant concentration. At Rib=-0.19 ， the dimensionless velocity difference （O.32） on the vertical center plane was increased by 10.34% .At Rib=-0.21 ，the maximum dimensionless concentration （O.88） at the pedestrian breathing level was decreased by 78.19% . The paterns of local urban flow fields and pollutant dispersion under different atmospheric stability conditions are revealed， providing a theoretical basis for targeted air quality improvement.

Keywords： step-down building; wind tunnel experiment; numerical simulation; atmospheric stability; pollutant diffusion

城市建筑物（工业建筑、医院、住宅楼等）屋顶烟囱释放的废气污染物，可能在不利扩散条件下影响相邻建筑室内和街道近地面空气质量。（剩余13023字）