Stability of Taylor-Couette flow in a finite-length cavity with radial throughflow

Linear stability analysis predicts that a radial throughflow in a Taylor-Couette system will alter the stability of the flow, but the underlying physics for the stabilization of the flow is unclear. We investigate the impact of radial inflow and outflow on Taylor vortex flow and wavy vortex flow in a finite-length cavity via direct numerical simulation using a three-dimensional spectral method. The numerical simulations are consistent with linear stability predictions in that radial inflow and strong radial outflow have a stabilizing effect, while weak radial outflow destabilizes the system slightly. A small radial outflow velocity enhances the strength of the Taylor vortices resulting in destabilization of the base flow, whereas strong radial outflow and radial inflow reduce vortex strength, thus stabilizing the system. The transition to wavy vortex flow is unaffected by small radial outflow, but is stabilized for radial inflow. For strong radial outflow the wavy vortex flow includes localized dislocations in the vortex structure.