Lu
My previous two questions A. & B. were intended to seek simple responses.
A. will take forever, or say, 1,000s and 1,000s of degrees.
B. will only take, say, 30 or 40 degrees.
The intent was to simply show that the phase angle can be more than 90-degrees or it can be less than 90-degrees.
Bottom line; 90-degrees is valid for a gyroscope, but not for a helicopter's rotor.
GP was a convenient way to describe the old teetering rotors, gimbal rotors and gyrocopter rotors
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heedm
For the fun of it, you might want to use your teetering pencil to look at the 'knuckle joint' v.s. 'cyclical Coriolis'. I built the same thing a while back to help envision the effects that are mentioned in the lead posting on the 'Aerodynamic - Coriolis' thread.
With the teetering pencil lying on the desktop and the 'mast' being rotated and not normal to the desktop, is the acceleration/deceleration caused by the knuckle joint or by a cyclical type of Coriolis?
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JoePilot
>"If the hinges (still at zero distance) were only free to flap and rigid in lead and lag then of course you could spin it. If you then changed the axis of rotation of the hub ..... "<
This is a description of the gyrocopter's rotor head.
>".......it would be equivalent of the NON free lead-lag hinge imparting a force which is in the original flapping direction. "<
This force, which is caused by tilting the hub, is because this tilting has pitched one blade down and pitched the other blade up. The blades now fly to position, hence 'aerodynamic precession'
[ 03 December 2001: Message edited by: Dave Jackson ]