Visualization of the Taylor Vortex Flows with a Small Aspect Ratio by the PIV

Wavy Taylor vortex flow with a small aspect ratio [Γ (=l/d)=1] is examined by the PIV system. Because the height of the annulus (l) is finite compared to the gap width (d), various bifurcation occurs in this apparatus. So far, a radius ratio was supposed not to have a big influence on the flow structure. But the experiment by the sudden acceleration of the inner cylinder with a small radius ratio showed that there was an area where the anomalous two-cell mode appears peculiarly. This two-cell mode is unstable and transfers to the wavy Taylor vortex soon. This critical Reynolds number is much lower than the past report