Laminar-turbulent transition in a laminar separation bubble: Influence of disturbance amplitude on bubble size and bursting

Direct numerical simulations of a short laminar separation bubble and its bursting are carried out. The bubble is developing on a flat plate due to an externally imposed pressure gradient. Laminar-turbulent transition is triggered by small disturbance input with fixed frequency to keep the bubble short. The short bubble reaches a statistically steady state, while switching off disturbance input yields a growing separation bubble. This phenomenon is denoted as bubble-bursting process. Disturbance input does not only prevent bursting, but can also serve to control the short bubble. Bubble size decreases with increased disturbance amplitude. Performance data on a NEC SX-8 super computer are compared for two different resolutions.