Flight Tests with a Natural Laminar Flow Glove on a Transport Aircraft.

Kurzfassung

As part of a national laminar low research program, flight tests with a glove on the right-hand wing of the DLR research aircraft VFW 614/ATTAS were carried out. The glove was especially designed to obtain three types of boundary layer instability: Tollmien-Schlichting instability (TSI), crossflow instability (CFI) and attachment line transition (ALT). In all tests, covering the Mach number range from 0.35 to 0.7, the complete transition line has been made visible by infrared image technique. Pressure distributions were measured and and used in stability analyses. Thus prediction by stability calculations at large Reynolds numbers has been obtained. Initial disturbance investigations provided information on the influence of engine noise and geometric steps on transition location.