Author(s)

T. Hawa & Z. Rusak

Abstract

A theoretical investigation of two-dimensional and viscous flows in a symmetric channel with a sudden expansion with right angles is presented. The analysis ex- plores the flow states around a critical Reynolds number Rec where asymmetric states appear in addition to the basic symmetric states when #e > #6c- The size of the asymmetric perturbation changes like \/#e - #6c- Linear stability studies of the various equilibrium states show that the symmetric states have a stable mode of perturbation when #e < #6^ and are unstable when Ae > Ee^. The asym- metric states have an asymptotically stable mode of disturbance. As a result, the symmetric flow states always evolve into the asymmetric states when #e > #e^. Space-and time-accurate numerical simulations using the unsteady Navier-Stokes equations are used to demonstrate the evolution of perturbations i

Keywords