Secondary flow phenomena in a rotating radial straight square channel

Abstract

Flow visualization results for secondary flow phenomena near the exit of a rotating radial straight square channel are presented to study Coriolis instability phenomena (formation of Coriolis vortices) and early laminar-turbulent transition for developing laminar flow regime with Reynolds numbers Re = 500 and 1500 and rotating speeds n = 20 ∼ 313 rpm. The smoke injection method was used for flow visualization. At lower Reynolds numbers, the channel rotation (Coriolis force) has a destabilizing effect. This is in contrast to the stabilizing effect of centrifugal force in curved channel flow. The flow visualization results are compared with the results of numerical solutions reported in the literature. The practical implications of the visualization study for future theoretical and experimental investigations are pointed out. Copyright © 1996 by Begell House. Inc.