On the multiplicity of solutions for the laminar flow between rotating disks at high suction Reynolds numbers

The problem of laminar viscous flow between coaxial rotating disks with high uniform suction rate was numerically analyzed. For steady-state flow, multiple solutions were found even at very low rotation Reynolds numbers. The multiplicity of the solutions depended on the dimensionless parameter Res/Rer, where Res and Rer are suction and rotation Reynolds numbers, respectively. Different zones for these solutions were established in a representative flow map with incorporated predominance of the characteristic parameters, and suction and rotation rate. Results for the unsteady case confirm the validity of the Boedewadt-type solution for relatively low suction rate and the vortex-type solution for cases with predominant suction rate.