What is Aeroelasticity? Is it one of the branches of Aerodynamics? :surprise:
It is the study of bending and vibrations in aerospace structures such as wings.
Wing flutter, wing divergence (shearing off), panel flutter, etc.
Speaking of flutter, there was a video aired recently on History Channel, that demonstrated how flutter was the probable cause for two Lockheed Electra airplane crashes in 1959-60. They used 4 prop engines
A NASA team analyzed the design and came to the conclusion that with wear, the propeller engine mounts became too loose and fluttered. That in itself did not cause the failure. However the flutter was at a harmonic of the wing's resonant frequency, stressing the wing to catastrophic failure and break off.
To be technical, the engine mounts don't flutter. They vibrate. Flutter is an aerodynamic excitation phenomena. One of the main things an engine mount has to do is effectively dampen any engine produced vibrations, whether they be mechanical or aerodynamic in nature.
Please forgive my ambiguity, I didn't mean the mounts fluttered.
When the engine mounts loosened, the propeller exhibited flutter. I see some refer to it as propeller whirl flutter. On the documentary, they indicated the propeller wobbled about its axis (analagous to wobble of our planetary poles)
Fred is this a classic example in aerospace engr classes?
I really don't know about that being a classic. I was an ME playing an AE. I have never heard that example until you presented it here. It was a bit surprising because my brother used to be a crew member on P-3's. The way I am most familiar with flutter is the testing we have to do on our engines prior to any airframe being given FAA cert. That scenario is a concern , but mostly our engines are not wing mounted.
That was a cool ariticle. I have always liked reading reports like that to see results of investigations. Good find.
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