Numerical simulations of the evolution of Taylor cells from a growing boundary layer on the inner cylinder of a high radius ratio Taylor-Couette system.

Abstract

The Taylor-Couette flow in the gap between two concentric cylinders has been studied numerically to show the evolution of Taylor vortices from pairs of ring-shaped vortices, at Reynolds numbers of 5 x 10(3) and 8 x 10(3) based upon the gap width. The cylinders have a high radius ratio of 0.985 and the inner cylinder rotates within a stationary outer cylinder. Initially, ring-shaped vortices are generated at the surface of the inner cylinder and spread into the gap. This is distinctly different from the formation of laminar Taylor vortices that grow from the end walls. Mixing of these ring-shaped vortices with the developing Couette flow then occurs and further ring-shaped vortices are generated. Some of these dominate the flow and begin to form Taylor vortices. Finally the Taylor vortices are stabilized and further vortex formation ceases. An analysis is also presented of the variation of shear stress with time.