Centrifugal instability and turbulence development in Taylor–Couette flow with forced radial throughflow of high intensity

Abstract

A numerical simulation of the turbulent flow between coaxial permeable cylinders is performed for the case of the rotating inner cylinder and superimposed radial flow through the annular domain. Both forced inflow and outflow are considered in a wide range of the rotation rate and throughflow intensity. Two configurations of the rotating cylinder are examined with an entire permeable porous surface and with lengthwise porous slots. The stable rotational fluid motion is shown to be concentrated within a boundary layer close to the inner cylinder surface at strong enough imposed radial inflow. Under such conditions, the centrifugal stability boundary is independent on the gap width. Flow stabilization due to the forced inflow is possible at any rotation rate considered for both the configurations of the inner rotating cylinder. The stabilization by the forced outflow is feasible only in the case of the entire permeable rotating cylinder. But there are always large-scale vortices in the gap under conditions of the forced outflow through the slotted rotating cylinder except for the relatively low rotation rate. Transition to turbulence in the boundary layer at the inner rotating cylinder may occur before the centrifugal instability onset at large enough inflow intensity. The boundary layer thickness and turbulence intensity are influenced by the inflow rate and differ between the cases of the entire permeable cylinder and the slotted one.