双柱振动诱导定常整流旋涡流动的实验研究

本文用流动显示实验研究圆形静止不可压缩粘性流体域内以圆心对称布置的双柱作同频同相小振幅振动时诱导的Ｓｔｏｋｅｓ层外的定常整流旋涡流动。实验表明，串列双柱当柱间距足够大时整流流谱呈八涡结构。当间距很小或为零时上涡结构。双柱的斜置有利于整流旋的合并，并柱间距接近至一定范围时，整流流动呈三维特征。振幅的减小和频率的降低使流动易出现三维现象。

Experimental Study of the Steady Streaming Vortex Flow induced by two oscillating circular cylinders

The steady streaming vortex flow induced by two oscillating circular cylinders in an incompressible viscous fluid which is otherwise at rest is studied experimentally by flow visualization.These two cylinders,arranged in a center symmetrical manner relative to the container,oscillate in the same phase and with the same frequency and with small amplitude.For two cylinders in tandem arrangement,the flow pattern of the steady streaming outside the Stokes layer is an eight vortices structure in the case of large distance between the cylinders,but is a four vortices structure in the case of a very small or vanishing distance.When the plane containing the two cylinder axes is tilted to the oscillating plane,the combination of the streaming vortices can be seen.Three dimentional features of the streaming flow take place if two cylinders approach each other within a certain distance.The smaller amplitude or frequency of oscillation,the more obvious the 3 D features are.