Flow structure behind a spanwise rib in channels of different geometry at moderate Reynolds numbers

Abstract

© 2019 Published under licence by IOP Publishing Ltd. Experimental study of laminar-turbulent transition in a rectangular channel with a semicircular rib has been carried out. The study comprised the flow visualization as well as direct numerical simulation of some flow configurations. The paper investigates the effect of the channel geometry (width and height), aspect ratio of the rib and blockage ratio on the mechanisms of transition to turbulence, formation of large vortical structures in the mixing layer behind the rib and on the critical Reynolds number at which the transition to turbulence occurs.