Graviman,
Re: Vortex induced noise and vibration from retreating blades (intermeshing & interleaving):[list=1][*]The teetering Bell 206L-3 in Prouty's book has a tip speed of 763 fps from rotor rotation. Assuming a forward speed of 100 knots, the advancing tip will be experiencing a tip speed of
(763 + 169) = 932 fps.
The tip speed of the retreating blade on the
Reverse Pitch Rotor, when the craft is traveling at 500 mph, is only 587 fps.
[*]The size of the vortices is also dependent upon the angle of attack. The usage of the
Advancing Blade Concept will reduce the angle of attack of the retreating blade.
[*]At 500 mph the craft will probably be out in front of any potential problem.[/list=1] Dave