Unsteady 3-dimensional calculation of the flow between concentric rotating cylinders

The flow between concentric rotating cylinders, which is called the Taylor vortex flow, shows various flow modes. The flow is classified into three modes. One is called the primary mode which appears with the gradual increase of the inner cylinder's rotation, and the others are the secondary normal and secondary anomalous modes which appears with sudden increase. Unsteady three-dimensional numerical simulations considering an effect of the inner cylinder's acceleration have been performed, revealing that there are different prossesses of occurrence between the primary normal and secondary normal modes. The bifurcation causing the above modes is observed at the same condition as with the experimental one. Transitions to wavy Taylor vortex flow from both modes appeared with increasing time. In addition, velocity and torque fluctuations, respectively, for a certain point in the field and for the inner cylinder are also shown.