B1.8 - Wind-tunnel experiments of advanced design of swept-wing with suction surfaces

The project B1.8 aims to acquire important knowledge to advance the LFC technology using suctions for future green aviation. Within the research activity of SE2A, it has been shown that LFC technology has a significant potential to reduce the total drag of aircraft by extending the laminar region on the lifting surfaces and fuselage. Extensive efforts went into developing robust low drag wing design with passive and active flow control (NLF/HLFC) at subsonic and transonic flight conditions. The importance of the proposed experimental work relies upon three main objectives: 1) proof of concept, 2) provide a database to validate the design tools, and 3) identify and quantify the “non-ideal” effects. Experimental research of LFC technology with suction insert has addressed flat-plate and unswept wings in current ongoing projects within the SE2A and providing a database for 2D flows. In practice the wings for the medium and long-range are swept wings, and the related physics is more complicated. In addition to Tollmien-Schlichting instabilities (TSI) instabilities Cross Flow (CF) and Attachment Line instabilities play an important role in the transitional flow regime. In addition, the flow has pressure distortion due to the fuselage conjunction, and the engine nacelle mounting on the wing results in 3D flows. However, a good quality database for 3D transitional flow is a lack in the research community. Therefore, this project “Wind tunnel experiments of advanced design of swept wing with suction surfaces” aims to fill this gap. The wing's advanced design includes an upper surface with one or two suction inserts, and a lower surface designed with a generic 3D flow, resulting from nacelle interactions and fuselage junction, with the option to install a TE flap. The wing experiments will be performed in the DNW-NWB subsonic wind tunnel facility.