开孔率对薄壁穿孔平板尾迹的影响研究

Research on the Influence of Porosity on the Wake of Thin Flat Plate

获得低湍流度水平一直是流体力学试验设备风洞或水洞设计的一个难点,通过对如蜂窝器或导流片等薄壁平板整流装置表面开孔来实现尾迹被动控制是一种新的途径。采用粒子图像测速(PIV)技术对开孔率分别为0、7%、14%和21%的薄壁平板的近尾迹区进行了试验研究,获得多种工况的二维速度场信息。结果发现,平板表面开孔改变了平板尾迹的涡旋周期性脱落频率,使尾迹的涡旋尺度多样化;平板穿孔可以有效地降低平板尾迹的湍流强度,降湍收益随着开孔率的增加先增加后趋向不变;平板穿孔可以提高平板尾迹的均匀各向同性。

For the design of wind tunnels and water tunnels for fluid mechanics experimental equipment,it has always been difficult to achieve a lower level of turbulence intensity.It is a new control by drilling a hole on the surface of thin flat such as honeycombs or corner vanes.The particle image velocity(PIV)technology is used to conduct experimental research on the near wake of thin flat plates with porosity of 0,7%,14%and 21%respectively,and obtain two-dimensional velocity field information under various working conditions.The results show that the porosity of the plate changed the vortex shedding period and the scale of vortex;the perforation could effectively reduce the turbulence intensity of the wake of the flat plate,and the turbulence reduction benefit increased with the increase of the porosity,the latter trend remains the same;plate perforation can improve the uniformity and isotropy of the plate wake.