Résumé : Current efforts in decarbonizing aviation aim at minimizing fuel consumption by reducing aircraft skin-friction drag. One solution is to delay laminar-turbulent transition using different approaches: either passive with Natural Laminar Flow, or active using Laminar Flow Control. In particular, wall suction is a Laminar Flow Control strategy known for effectively delaying transition. However, implementing a suction system is likely to introduce surface defects, which could trigger transition, and therefore cancel any drag reduction achieved by wall suction.

The topic of this presentation is an experimental investigation on the combined effect of surface defects and wall suction on boundary layer transition. First, the destabilizing effect of a porous panel on the boundary layer will be discussed. Next, the robustness of wall suction to delay transition in the presence of surface defects will be shown. Finally, these results will be compared to existing transition models.