摘要
为了更好地发挥防护林带在矿区生态环境保护中的效用,采用数值模拟的方法预测防护林带的绕林流场,其中将气流-树木相互作用视为阻力项添加到动量控制方程中,由障碍物表面对空气流动的阻力来描述林带的遮蔽效应.通过对雷诺时均控制方程的离散求解,得到了通风型条状林带、疏透型网状林带、紧密型块状林带各自对应的流场、压力场和湍流动能场的分布.结果表明:不仅林冠疏透度对防护林带的遮蔽防风有明显影响,而且树木间的株距对林带整体的遮蔽效果也有比较显著的影响,为避免穿流风对遮蔽效应的影响,林带宽距比不宜超过1.3;疏透度为31%的网状林带的有效防护范围大,防风效果好而且水土保持性强;紧密型块状林带,林后速度衰减幅度大,可抑制附着在叶片上粉尘的再次扬尘.
In order to practically predict the effect of the tree belt windbreak in mine-area the flow through porous tree belts was numerically made. The airflow-tree canopy action environment protection, was considered into the momentum equation as the resistance term, and then the resistance between obstruction and airflow was expressed numerically. The each velocity, pressure and kinetic energy distribution of the sparse strip belt, draught meshy belt and tight nubby belt were obtained by calculation based on time-average Renoyld equations. The results show that not only the porosity does greatly affect the windbreak, but also the tree distance does. The distance is not beyond 1.3 to avoid air leak. The tree belt with porosity 31% has bigger windbreak range and better characteristics for abating wind erosion. The tight nubby tree belt is advised to restrain the particles adhering on the leaves refloating for large velocity deficit in trees.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2008年第9期997-1001,共5页
Journal of China Coal Society
关键词
防护林带
矿区环境保护
绕林流场
数值计算
tree belt
mine environment protection
air flow through trees
numerical calculation
