Experimental investigation on periodic rolling of a delta wing flow at transonic Mach numbers

Experimental simulation was conducted in the Transonic Wind-Tunnel Gottingen (TWG) of DNW with the 65 degrees cropped delta wing AEROSUM model, which was managed in the DLR project SikMa (Simulation of complex maneuvers). Besides unsteady force and surface pressure measurements an optical deformation measurement technique was applied. In order to a better understanding of the instability behavior of free-to-roll rolling motions of a delta wing now a high-time resolution optical technique was applied to get hints i.e. to coupling effects of aerodynamic flow with elastic wing model which influence the stability of the delta wing flow. Therefore defined periodic rolling motions were investigated. Discontinuous jumps of normal deformation amplitudes of the rear flaps are recognized while the harmonic rolling motion of the wing body. Although technical or frictional effects cannot be excluded, it seems possible to explain this behavior by aerodynamic-elastic coupling effects of the delta wing now with the elastic wing-flap structure.