Characterization of a highly efficient chevron-shaped anti-contamination device

Abstract

This paper is devoted to the characterization of an optimized chevron-shaped anti-contamination device (ACD). This device can prevent efficiently the propagation of turbulence from the fuselage along the attachment line (hypothetical streamline that spreads the flow going to suction side and the one going to pressure side) of swept wings and enables the development of a new laminar boundary layer downstream. More specifically, the aim is to prevent boundary-layer transition along the attachment line by a contamination process. This process is characterized by the typical Reynolds number $$\overline{R}$$ and the associated Poll’s criterion. Thus, ACD efficiency will be expressed in terms of $$\overline{R}$$ values. Some experiments performed on a new numerically optimized ACD have shown its ability to prevent leading-edge contamination up to $$\overline{R}$$ values close to the natural transition process of the laminar boundary layer along the attachment line. The corresponding stability analysis of the laminar boundary layer is made using the Gortler–Hammerlin stability approach. The study is completed with the different transition processes that can occur downstream the attachment line, around the airfoil, especially with crossflow analysis.