重烟羽扩散的风洞模拟实验研究

Wind tunnel experiments on dense gas plume dispersion

介绍利用风洞研究重气烟羽扩散特征以及围墙和树对其影响。实验使用的源是地面上的圆形面源。通过实验 ,提出了基于“变形源”假设的重气烟羽扩散物理过程 ;发现围墙在低 Froude数下对重气烟羽有阻挡作用 ,而树对重气没有阻挡作用 ,但对“变形源”的形状有影响 ;从对危险气体的防护角度看 ,对测量范围的围墙外 ,围墙的防护效果明显 。

This paper introduces the investigation of the characteristic features of the dense gas plume and the influence of walls and trees on dense gas plume dispersion by using the wind tunnels, in which the plume was created by a small circular source at ground level. Based on the experiment, the author has put forward the physical process of the dense gas dispersion, on 'the metamorphic source' hypothesis. The experiment also shows that: 1) the walls could block the dense gas plume in lower Froude number (Fr); 2) the trees had effect on the shape of the 'metamorphic source' instead of blocking the dense gas plume; 3) the ground axis concentration outside the wall was reduced obviously by the wall; and 4) the effect of the trees on the dispersion, which is outside the wall, is not obvious.