建筑物对污染物扩散影响的数值与风洞模拟研究

采用k-ε（RNG）与RSM湍流模型对处于方形建筑物不同位置污染源所排放污染物的扩散规律以及建筑物对流场的影响进行模拟,并且与相应的风洞试验结果进行了比较。流场分析结果表明：数值模拟能够较好地模拟建筑物前方迎风侧停滞回流、顶部回流以及后方空腔区等。浓度场分析结果表明：建筑物前方迎风侧以及顶部回流区污染物扩散的数值模拟结果与风洞试验结果基本相等,而在建筑物后方空腔区污染物的数值模拟结果略高于风洞试验结果。综合分析并与风洞试验结果相比较,RSM模型能够较好地模拟污染物浓度场以及建筑物周围流场的变化规律。

Numerical and wind-tunnel simulation on the effect of building on pollutant dispersion

The flow and dispersion of gases emitted by sources located near bluff building separately studied in wind tunnels were determined by the commercial model STAR-CD using the RNG/e-e, and the Reynolds stress RSM turbulence. Inlet conditions and boundary conditions were specified numerically to the best information available for each fluid modeling simulation. Calculations are compared against the wind-tunnel measurements, and the validation of flow mod cling of this model is analyzed. The result of flow field＇s analysis shows that, numerical simulation can better simulate the windward side of the stagnation backflow, the top backflow in front of the building and the rear cavity zones, etc. The result of concentration field＇s analysis shows that, numerical simulation＇s result of the pollutants＇ dispersion is in good agreement with that from wind tunnel experiment in the windward side and the top backflow zones in front of the building, however, numerical simulation＇s result of the pollutants＇ dispersion is slightly higher than that from wind tunnel experiment in the rear cavity zones. As a whole, compared with wind tunnel experiment, the RSM model can better simulate the variation of pollutants＇ concentration field and flow field around the buildings than the RNG be model.