摘要
作为减少风力、创造相对低速的局部微环境的主要措施,防护林风障对于保护道路、农田免受风沙流和风雪流侵袭,减少露天粉状物料堆对环境的污染有着重要意义.对于空气穿过风障这一复杂问题,采用高阶封闭模型——雷诺应力模型(RSM)计算,并对气-叶阻力系数Cd,进行了理论推导,得出它是与叶片面积密度、风障结构以及下垫面粗糙度有关的变量,从而证实了相关现场观测结果.最后取不同的Cd值进行了数值计算,预测了外流场风速的分布情况.
As an effective measure to lessen wind speed and create a local low-speed microenvironment, canopy, namely windbreak, is of great importance in protecting roads and farms from being damaged by sand streams, and snow streams and in reducing the air pollution caused by open-air power piles. Airflowthrough the windbreak is indeed a complicated phenomenon,so the Renyold shear-stress budget model (RSM) is introduced into the momentum dynamical equation to closure high-order control equations. Moreover,the resistance coefficient between the air and canopy Ca, an important dynamical paramater, is derivated in theory and confirmed to relate with the variables such as leaf area density, windbreak constructure and earth surface roughness, which can verify the relevant observation outcomes. At last, numberical calculation is made according to the different Cd value and windspeed distribution around windbreak is predicted.
出处
《同济大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2004年第1期31-34,共4页
Journal of Tongji University:Natural Science
关键词
高阶封闭模型
气-叶阻力系数
风障
high-order closure model
resistance coefficient of air-canopy
windbreak
