Abstract: High Angle of Attack (AoA) maneuverability is the symbolic characteristic of the fourth generation fighter. Our advanced fighter utilizes twin V-tails configuration, and this sort of aerodynamic design is proved to be well controllable at high AoA maneuvering flight. During high AoA maneuvering flight, the strong flow disturbance induced by the burst vortex shedding from fore-body impinge inevitably on the twin V-tails, and will induce severe buffet. The V-tails buffet will cause not only remarkable reduction of flight quality, but also structural fatigue damage, leading to high maintenance cost. This paper describes in detail the key techniques achieved during the engineering manufacturing and design of an aircraft with all-moving twin V-tails, which include: the design technique of rigid/ flexible hybrid model and testing methods of all-moving V-tail buffet wind tunnel test, as well as the principle of similarity transformation method which transforms test data from buffet wind tunnel test to fighter flight condition; the CFD/CSD coupling calculation method based on the RANS/LES hybrid algorithm; active control technique on V-tail buffet response alleviation based on macro fiber composite piezoelectric actuators and Positive Acceleration Feedback (PAF); the V-tail buffet fatigue spectrum generation method and test program. This research has established a set of systematical theoretical analysis techniques, design criteria, and test methods for aircraft V-tail structure buffet dynamic strength design and test of advanced fighters and UAVs.

Key words: buffet, buffet spectrum, dynamic fatigue, wind tunnel test, shedding vortex, macro fiber composite