【摘要】 根据大气风向频率特征,提出风向频率加权(W DFW)方法,结合求解三维N-S方程、传热传质的对流扩散方程和k-ε湍流模型来预测实际大气条件下局地大气流动和污染物扩散规律,并与现场采样分析结果进行对比.结果表明:数值模拟结果和观测数据吻合较好;污染物浓度在尾气管后部的1~4 m范围内迅速衰减,且其扩散特征主要受尾气排放速率和排气浓度的控制,在更远的区域则主要受环境气象条件的影响;但在排气管轴向近于人的呼吸带高度,即使距离尾气管较远,污染物浓度也是较高的.更多还原

【Abstract】 A wind direction frequency weighted(WDFW) method based upon the atmosphere wind direction frequency characteristics,combining with solving the 3D Navier-Stokes equations,the mass and heat transfer equations as well as the standard k-ε turbulence models was proposed to model the local airflow and the dispersion of vehicular exhausted plume under real atmospheric conditions.The numerical results were compared and validated with the measured concentration and a good agreement was achieved.It is shown that the pollutant concentration is decreased rapidly with the distance from the tailpipe in a range of 1~4m behind the tailpipe and the dispersion charactersitics are mainly controlled by the exhaust flow rate and plume concentration,whilst those in a far region from the tailpipe exit are influenced by the ambient air and local weather conditions.However,the concentration still has high level at a height close to the breathing region along the tailpipe axis.更多还原