住宅小区污染物扩散的数值模拟分析

采用计算流体动力学CFD的方法,以哈尔滨市某新建住宅小区为研究对象,对该小区南区多种工况下室外气流流动和污染物浓度扩散情况进行了三维数值模拟分析。模拟结果表明:在建筑群周围产生湍流和低速区的地方,会出现污染物浓度累积情况。小区内污染物浓度的变化特征是随着离污染源的距离增大逐渐减少,其垂直分布仍符合地面源排放的扩散分布形式;不同风速条件下随风速增大,则污染物散布愈广,相应局部浓度降低。对采样试验结果与相应数值模拟结果进行了对比,两者在趋势上比较一致,通过误差分析,得到采样试验与数值模拟结果的平均偏差仅为0.013mg/m3,平均比例误差仅为0.406,证实了模型的有效性。

NUMERICAL SIMULATION AND ANALYSIS OF POLLUTANT DISPERSION IN THE RESIDENT DISTRICT

Based on the method of CFD, the research takes a newly - built resident district in Harbin as the object of numerical simulation and monitoring. The paper analyzes the airflow and dispersion of vehicle exhaust gas under different kinds of states. The results show that partial turbulence is produced around the building group. These rapids areas are controlling the pollutant dispersion. In the rapids and the low speed places around the building group, pollutants accumulated. Pollutant concentrations will decrease as the distance from measuring point to source increase. Vertical distribution of pollutant concentrations is in accordance with the rules of source on the ground. Pollutant concentrations will spread broadly as the wind speed rise, therewith the local concentrations decrease. Comparing the simulation results with the sampling analysis, it indicates that they are quite consistent in the tendency, which proves the validity of the model. The error analysis further indicates the tally of monitoring and numerical simulation. The average deviation is only 0. 013mg/m^3, the average proportional error is only 0.406.