Centrifugal Instability in the Backward-Facing Step
Résumé
Three-dimensional stationary structure of the flow over a backward-facing step is observed experimentally showing a periodicity in the spanwise direction., with longitudinal vortices. A local Rayleigh discriminant and a local Görtler number are computed from numerical simulations. It is shown that the observed instability is consistent with a centrifugal instability raising just downstream the recirculation zone.