Aeroelastic Characteristics of Horizontal Tail in Buffeting Separated Flow

The horizontal tail of a large aircraft, comparable in size to a medium-sized aircraft’s wing, poses significant aeroelastic risks. Under transonic conditions, the horizontal tail may reside within the separated wake flow induced by wing shock buffet. Subjected to unsteady aerodynamic loads, this interaction causes aeroelastic issues due to forced-separated flow. This study investigates the influence of wing buffet-separated flow on the horizontal tail’s aeroelastic behavior, employing a reduced-order model and computational fluid dynamics and computational structural dynamics (CFD/CSD) time-domain simulations. Results show that the interaction between wing buffet flow and tail shock waves reduces local flow stability. Moreover, nonuniform separation vortices around the tail induce large fluctuating pressure differences between upper and lower surfaces, coupling the tail’s plunge mode with the dominant fluid mode and expanding its aeroelastic instability range. Additionally, the broadband frequency characteristics of the wake flow coincide with the tail’s natural frequencies, exciting pitch-mode aerodynamic resonance. Altering the structural parameters of a horizontal tail immersed in wake flow also modifies its aeroelastic characteristic.