边界层大气环境与空气污染问题的风洞流体模拟实验

FLUID MODELING EXPERIMENT IN WIND TUNNEL FOR ATMOSPHERIC ENVIRONMENT AND AIR POLLUTION IN PBL

在大气环境风洞中,采用人工形成边界层的方法,建立一定厚度的模拟边界层,测试确定边界层特征量,如粗糙度长z。风廓线指数n等。实验揭示了形成大气边界层的物理机制。用烟云照相法对模拟形成的高架点源排放烟流的抬升高度相大气扩散参数作了实验测定,并采用波动烟流法进行数据处理。讨论了排烟速度Vs和环境风速u对烟气动力抬升的影响;此外还对阶跃下垫面条件和障碍物后旋涡区中的扩散进行了分析。

In the environmental wind tunnel a man-made method was used to develop a simulating boundary layer with a depth and determine its charcteristic parameters, such as, surface roughness length Z0, power index of wind profile etc. The physical mechanism of developing the boundary layer in wind tunnel has been revealed. The photographical method for simulating plumes from a elevated point source was used to measure the diffusion parameters and plume rise height and a method named fluctuation plume was used to analyze the experimental data. In the paper some effects on dynamic rise of the plume by envi ronmental wind speed (U) and exit speed (Va) of gases from stack has been discussed, in addition, some dispersion phenomena under step-underlying surface condition and in eddy area behind the structure have been analyzed.