Originally Posted by
MeddlMoe
I think here is a fundamental misunderstanding by some of you:
The coriolis effect, gyroscopic effect, and centrifugal force are not some kind of "extra physics" or "magical effects" that occur on top of conservation of mass, energy and momentum. These effects are just apparent phenomena when analyzing movements in rotating reference systems and are caused by the conservation of mass, energy and momentum.
So the question "is it coriolis, or conservation of momentum" doesn't make sense, because the latter causes the first.
Yes! There’s a huge tendency for people to reason based on labels and word association, instead of physical behavior. If the explanation for the phenomenon they’re familiar with is label A, and someone else says it’s B, they reject B because it’s not A, instead of examining what’s happening in B and how that may or may not interact (or even may be the same, or an example of) with what’s happening in A.
It’s a fairly simple part of how matter behaves, if it’s going in a straight line and a normal force acts on it, the path deflects. Now if initially it’s going in a circle because it’s attached to the center, and a normal force acts on it, it deflects the same way. Because the new post-deflection path is still wrapped around a circle, the maximum displacement before it comes back, is 90 degrees after where the force acted. May have to draw a picture to really see it, but it’s not too complicated. But now, when you give a name to the force that caused the deflection (lift), this… somehow doesn’t happen any more?
I would like for the people who reject the label (gyro precession) to instead say why they reject the mechanic behind it.
Originally Posted by
HissingSyd
Indeed it is. Phase lag has almost nothing to do with gyroscopic effects nor with forces and their delayed effects. It is almost entirely an aerodynamic effect - a result of flapping to equality of blade thrust in a cyclicly varying aerodynamic environment. In an ideal scenario, with a freely articulated rotor responding to cyclic control input, is is 90 degrees.
Anything more complex will perturb that, but not grossly. I am not at all sure about teetering rotors. ;-)
How is a “gyroscopic effect” different from an “aerodynamic effect” in this case? Doesn’t the aerodynamic effect impart a normal force on the blade, causing its path to deflect (flap) into a new circle where the maximum difference from the old circle is 90 degrees after the force change?