Turbulent flow over a cylinder confined in a channel at Re = 3,900

Abstract

This paper presents data from numerical simulation of the flow over a cylinder confined in a channel at Reynolds number of 3,900. Direct numerical simulation (DNS) of the flow field from blockage ratio of 0 (i.e. the canonical flow over an unconfined cylinder) up to blockage ratio of 0.7 have been performed. At large blockage ratios, an adverse pressure gradient develops and the boundary layer on the channel walls separates and interacts with the cylinder wake. It is observed that the interaction gives rise to complex flow dynamics, affecting the size of the wake, making the wake asymmetric and also resulting in a decrease in the intensity of the turbulent fluctuations in the shear layer. An..