Buffeting
Buffeting is a phenomenon of aeroelasticity . It is the structural response of the aircraft structure to an aerodynamic phenomenon called buffet , a transient (time-varying) flow around the wing. Buffet results in a periodic oscillation of lift and drag , which means for the aircraft structure that the wing is excited to elastic oscillations. The frequencies of these vibrations are usually in the range of the natural vibrations of the wing structure (bending and torsion) and therefore have a strong tendency to stimulate the wing to vibrate strongly.
Consequences
The consequences for the flight condition can be significant. On the one hand, buffeting can bring the aircraft structure to its static or dynamic limits and thus lead to failure of the structure. On the other hand, the vibrations are in a frequency and amplitude range that people perceive as strong vibrations. The comfort of a quiet cruise would be severely impaired. The periodic fluctuations in the lift of the aircraft can also become so great that there is no longer sufficient lift available for travel or maneuvering flight. The ability to control the aircraft can be severely impaired and lead to a dangerous flight condition ( resonance catastrophe ).
Probability of occurrence
Commercial aircraft are designed so that buffeting does not occur in any flight condition. The maximum speed of such an aircraft is limited by this buffeting limit. More precisely, buffeting may not even start at the maximum permissible airspeed if the maximum maneuver load (maximum lift) is being flown at the same time, e.g. B. at the interception curve to the maximum climb.