Experimental investigation of local vortex roughness receptivity of a boundary layer on an airfoil

Receptivity coefficients of vortex-vibrational type at excitation of 3D Tollmien-Schlichting waves in a boundary layer on a swept wing

“…Localized excitation of 3D TS-waves by freestream vortices in presence of surface roughness elements was investigated in experiments on a flat plate [5,6] and on an airfoil [7]. Estimates of the corresponding localized receptivity coefficients were obtained for the "vortex-vibrational" [5,6] and "vortex-roughness" [7] receptivity mechanisms.…”

“…Localized excitation of 3D TS-waves by freestream vortices in presence of surface roughness elements was investigated in experiments on a flat plate [5,6] and on an airfoil [7]. Estimates of the corresponding localized receptivity coefficients were obtained for the "vortex-vibrational" [5,6] and "vortex-roughness" [7] receptivity mechanisms. Similar results were obtained later for a 3D, swept-wing boundary layer at excitation of cross-flow (CF) instability modes by both vortex-roughness [8] and vortex-vibrational [9] localized receptivity mechanisms.…”