Numerical study of a flat-crested oscillatory boundary layer flow over a flat plate

• Oscillatory boundary layer flow over flat plate with steep pressure gradient.
• Flow regime simulated spans from fully laminar flow to fully turbulent flow.
• Results predicted by k–kL–ω model compare well with DNS results.
• The k–kL–ω model accurately predicts the onset of transition.

An oscillatory boundary layer flow with a flat-crested freestream velocity profile and a steep pressure gradient over an infinite flat plate at rest was simulated using the k–kL–ω turbulence model. The simulations were conducted for a Reynolds number range of 32 ⩽ Reδ ⩽ 10,000 that spans from fully laminar flow to fully turbulent flow. The k–kL–ω model was validated by comparing the predictions with DNS results for the intermittently turbulent flow regime. The good agreement obtained between the k–kL–ω model prediction with the DNS results indicate that the k–kL–ω model is able to accurately simulate transient intermittently turbulent flow and as well as accurately predict the onset of turbulence for such oscillatory flows.