Prediction of large-scale transition features in the wake of a circular cylinder

Abstract

A direct numerical simulation of the viscous incompressible flow around a circular cylinder is carried out in the Reynolds number range 2000–10 000 by solving the two-dimensional time-dependent Navier–Stokes equations, using a pressure–velocity finite-volume method. Apart from the vortex shedding phenomenon, it is shown that transition waves develop in the separated shear layers and lead to mixing layer eddies. The ratio of the computed transition wave frequency over Strouhal number is in good agreement with experimental results. This allows the supposition that the instability leading to mixing layer eddies has a predominant two-dimensional origin and is predicted by the Navier–Stokes equations.