Experimental Investigation of Vertical Tail Buffeting on a Triple-Delta-Wing Configuration in Transonic Flows

Abstract

Modern high-agility aircraft are often subjected to buffeting phenomena at subsonic and transonic Mach numbers and high angles of attack. This study investigates vertical tail buffeting on the DLR-F23-T triple-delta-wing configuration at Mach numbers representative of flight conditions. Wind tunnel experiments were performed in the DNW-TWG to analyze aerodynamic characteristics, surface pressure distributions, pressure fluctuations, structural response, and quasi-steady hysteresis effects. In addition, an experimental modal analysis was conducted to characterize the structural dynamics of the investigated configuration. The results show that buffet onset shifts from an angle of attack of 21° at Ma = 0.55 to 19° at Ma = 0.85, indicating an increasing influence of compressibility effects on the vortex-dominated flow field. Spectral analyses identify a dominant buffet-related peak at a reduced frequency close to k = 1 for both Mach numbers. Furthermore, pronounced hysteresis effects in lift and pitching moment indicate significant nonlinear aerodynamic phenomena associated with the vortex-dominated flow field.