前置隔板对圆柱绕流影响的实验分析

对经典的圆柱绕流模型,运用前置隔板对流场进行控制。利用粒子图像测速(PIV)方法在自循环水槽中研究了雷诺数为1 800时,柔性和刚性2种不同刚度的前置隔板对圆柱绕流的影响。研究发现:柔性隔板自由端的弯曲增加了对流场的额外扰动,并且柔性隔板弯曲变形会诱导产生脱落涡,导致尾迹流场的主频发生变化。在圆柱下游流场,无隔板工况与柔性隔板工况的回流区长度相当,刚性隔板工况的回流区相较之下则更长。结果显示:前置隔板还能在一定程度上减小圆柱绕流的阻力。 

Experimental analysis on flow past circular cylinder attached to frontal splitter plate

Considering the classic circular cylinder flow model, a frontal splitter plate was introduced to explore the influence on the flow past a circular cylinder in a water channel. Particle imaging velocimetry (PIV) was utilized to investigate the flow characteristics of the circular cylinder attached to a splitter plate with two different stiffness (flexible and rigid) respectively at the Reynolds number of Re=1 800. Owing to the bending deformation of the flexible plate's leading point, an additional perturbation results in the generation of vortex on the tip of the plate and even varies the dominant frequency in the wake region.In the downstream of the cylinder, the sizes of reverse flow region in the flexible plate condition and the no-plate condition are similar, while the size of reverse flow region in the rigid plate condition is larger. The experiment results show that the drag force of the circular cylinder could be reduced in a degree by the frontal splitter plate.