Analyzing the Flow in Annular Gap With a Restrictor Mounted on Outer Cylinder

Abstract

The flow in annular gap with a restrictor mounted on outer cylinder is numerically simulated based on the hybrid Reynolds Averaged Navier-Stokes (RANS)/Large eddy simulation (LES) model. In stationary inner cylinder case, the pressure drop, mean axial velocity profiles and characteristic length scale of the recirculation zones are analyzed. Then the effects of rotating inner cylinder on the axial pressure distributions and the size of recirculation regions are examined. With the increase of rotating Reynolds number, the pressure loss of flow past the forward-backward step pair is greatly increased. Meanwhile, the transient pressure difference between the upstream inlet and downstream outlet gradually becomes fluctuating periodically due to the vortex shielding at the edge of backward step regularly. And the amplitude of the fluctuating pressure difference is comparable to its mean value. Moreover, the size of recirculation regions is reduced with the rising azimuthal Reynolds number, resulting from the interacting with enhanced Taylor vortices.