Interaction of crossflow modes with forward-facing steps: insights gained from DNS

Kurzfassung

In recent studies, both experiments and simulations have explored how surface roughness affects laminar-turbulent transition in swept-wing scenarios. This work specifically addresses the effects of forward-facing steps (FFS) and is inspired by the experimental observations of Rius-Vidales & Kotsonis [1], which identified a non-monotonic relationship between step height and the location of transition. Notably, an unprecedented delay in transition —compared to scenarios without FFS— occurs when stationary crossflow vortices interact with a shallow FFS. Conversely, the interaction with a higher FFS leads to an upstream advancement of the transition front location. The present work aims to replicate the experimental setup and conditions described in [1] via direct numerical simulation (DNS), with the ultimate goal of further elucidating the flow physics behind the observed experimental behaviors.