Numerical solution of laminar flow generated in an annulus by rotating screens

The governing equation and the appropriate boundary condition describing stationary laminar flow in a curved channel and in an annulus with one (upper) and two (upper and lower) rotating screens, were solved numerically by finite-difference method. In the curved channel multiple solutions were obtained in accordance with the predictions of previous theoretical and experimental investigations. In contrast to that, no multiple solutions were found for the flow in an annulus, neither with two nor with one rotating screen. The numerically computed axial velocity distributions in annulus were compared to the corresponding experimental profiles measured in a turbulent flow of a homogeneous fluid created in annulus by one or two rotating screens. The qualitative agreement between the results was unexpectedly good.