Novel states in Taylor-Couette flow subjected to a Coriolis force

Abstract

We present experimental results for Taylor-Couette flow subjected to a Coriolis force. We used an apparatus consisting of two concentric cylinders with the inner one rotating, and with a radius ratio near 0.75. It was mounted with its axis horizontal on a table which rotated with angular velocityΩ about a vertical axis. For sufficiently lowΩ, the first bifurcation upon increasing the inner-cylinder rotation rate ω was to tilted vortices. With further increase in ω this bifurcation was followed by a secondary one to time-periodic tilted vortices. The two bifurcation lines met at higherΩ. The initial bifurcation then became one to tilted traveling vortices. For even larger values ofΩ, the flow immediately above the initial transition was disordered, and for sufficiently largeΩ the initial bifurcation was to a featureless turbulent state. We studied these transitions with three different outer cylinders. Two had symmetric spatial ramps terminating both ends of a straight section to reduce the effect of the rigid, nonrotating ends, and one had no ramps. The transition to featureless turbulence in the apparatus with ramps became hysteretic over a range ofΩ.