林带阻力系数与透风系数关系的理论分析

Theoretical analysis on the relation of drag coefficient to permeability of windbreaks

根据冲量定理分析了林带对气流的阻力，首次得到了林带阻力系数的估算模式（Ｃｄ＝（１．８＋０．２α）（１－α）ｓｉｎ２ω，并利用有关文献发表的资料进行了验证．文章还对来流平行林带时林带对气流的阻力进行了讨论，指出来流平行林带时林带对气流的阻力仅为来流垂直林带时林带对气流阻力的０．７—１．１％，可以不予考虑．

The drag of windbreak is analysed by impulse theorem in this paper.A simulation model of drag coefficient of windbreak,Cd=(l.8+0.2a)(1-a)sin'ro,is presented, and it is tested in terms of those data from published papers.A parallel--force of windbreak is also discussed.The parallel -force of windbreak whose value is 0.7--1.1% of the normal force can be neglected.