Buffeting test

What is meant by the term buffeting?

In the area of aeroelasticity, buffeting refers to a strong vibration that occurs as a result of the airplane body reacting to turbulent compression shocks. Normally, buffeting occurs in the transonic speed range, i.e., in the range in which the inflow velocity is subsonic but the velocity on the wing is already supersonic.  This can result in a periodic change between lift and drag, causing, e.g., the wings to vibrate elastically. This is a high-frequency aeroelastic instability that primarily affects the lateral wing panels or the rear of the aircraft. 

What role does buffeting play in the safety of an aircraft?

Buffeting can have dangerous consequences: if the periodic fluctuations affect the lift excessively, there may not be sufficient lift for flight. The controllability may also be greatly limited. Over time, the loading shortens the lifetime of the used materials. The maximum velocity of normal commercial aircraft is limited in such a way that buffeting cannot occur and so that the aeroelastic stability is not endangered.

What purpose does the data collected in the buffeting test serve?

The empirical data collected in the buffeting tests during flight vibration tests (FVT) provides information on:

• Possible parameters that could predict the tendency of an aircraft to experience buffeting
• Realistic requirements for the development of future simulation methods and tests for controlling or preventing buffeting

How is buffeting measured?

Buffeting represents a load on the aircraft structure. To determine the aeroelastic stability of an aircraft, the effects of the load are measured during the flight vibration test (FVT) under real flight conditions using accelerometers.

How does buffeting differ from flutter?

Both events are aeroelastic phenomena. Unlike buffeting, however, flutter amplifies itself and is, therefore, destructive in nature.