树冠结构参数及附近风场特征的风洞模拟研究

Wind tunnel experiment on canopy structural parameters of isolated tree and wind velocity field characters nearby

根据风洞模型实验 ,分析了树冠结构参数 (疏透度 β、透风系数α)和附近的风速场特征 .结果表明 ,透风系数与疏透度之间符合幂函数关系α =β0 .6,树冠附近的风速减弱区为椭球形立体空间 ,减弱区随树高、冠幅的增大而增大 ,随透风系数 (或疏透度 )的增大而减小 ,在水平和垂直剖面上 。

The canopy structural parameters(porosity β and permeability α) of isolated tree,and the wind velocity field character nearby were analyzed by wind tunnel experiment.The results show that α and β fitted the function of α=β 0.6 ,and the wind velocity nearby decreased in ellipsoid contour. The contour increased with increasing tree height and canopy width,and decreased with increasing permeability (or porosity).The isotach became the shape of ellipses or elliptic segments in horizontal and vertical plans.