Influence of a forward-facing step on crossflow instability and transition: An experimental study in a swept wing boundary-layer

The market growth expected for commercial aviation in the coming decades and the increasing social awareness regarding the effects of global warming are driving significant technological developments necessary for emission reduction in future transport aircraft. From the aerodynamics perspective, a significant increase in aircraft efficiency can be obtained by applying Laminar Flow Control (LFC) techniques. The objective of LFC techniques is to reduce the skin-friction drag component by delaying the laminar-turbulent transition through the stabilisation of boundary-layer instabilities. Relevant to high-subsonic transport aircraft is the development of Crossflow (CF) instability, which manifests as a series of co-rotating vortices inside the boundarylayer flow on swept aerodynamic surfaces...