【摘要】 利用粒子图像速度场仪(PIV),采用2帧-互相关的分析技术,对紧密型、疏透型和通风型防护林流场的流动特征在环境风洞中进行实验研究。通过PIV系统测量,得到不同类型防护林绕林流场的速度矢量图、流线图和涡量场图,并对各个流场特征进行探讨。更多还原

【Abstract】 In order to make the windbreaks play to the function of weakening winds and fix drifting sand better,this paper explains three kinds of windbreaks the characteristic of function,looks for the relation with structure and effect of protecting of windbreaks further.Flow characteristics of flow fields through various windbreaks have been experimentally investigated by Particle Image Velocimetry(PIV).The flow fields are measured by using the two-frame cross-correlation technique in low speed wind tunnel.The experiment measure scope in large,through improving CCD supplementary tool,and adopting certain image handling technology,whole flowfield of the 2 dimensions area within wind tunnel (1400mm×320mm) are displayed.Experimental result show a series of velocity vectorfields,stream line graphs and vorticity field of various windbreaks.Through analyzing structure characteristic of different kinds of windbreaks.We can conclude that the porousity windbreaks affect best completely among three kinds of windbreaks.更多还原