Coriolis vs Conservation of Angular momentum
but it's not a huge angle change (about 5 degrees according to my trig)
Up on deck and 50m from the cg, the physical heaving and rolling gets a little exciting. And I have only landed on bigger (for Oz) boats of Supply and Tobruk and the carrier Melbourne. The smaller boats need balls of stainless steel.
Then try doing it at night
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Originally Posted by [email protected]
sorry, I misread your post - it is 180 degrees because the pitch change starts 90 degrees before max rate of pitch increase and hence max rate of flap up.
The maximum "rate of flap up" i.e. the vertical speed is reached at the end of upward cyclic component of the aerodynamic force that is controlled by the AoA, not at its peak.
You need the gyroscopic effect to get 90 degrees peak to peak.
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Originally Posted by [email protected]
Then try doing it at night
The AI is a gyroscope; the rotor is not.
There is no thrust from the rotor and no blade produces any thrust at any point in its path.
I trim the cyclic forward and the tip-path-plane tilts down. The blades are flapping cyclicly.
There is no thrust from the rotor and no blade produces any thrust at any point in its path.
Explain this and you will have explained why an 'ideal' articulated rotor has 90 degrees phase lag. You will also be able to give an indication of why offset hinges, delta hinges etc reduce the phase lag. You will do this without any mention of gyroscopes, gyroscopic effect or gyroscopic precession.
Of course, this will be a 'simple explanation' of the gross behaviour of a rotor in quasi-steady-states. It will not explain the behaviour in transitory states, when I fully expect the dynamics of rotating masses, 'gyroscopic effects' if you like, to be important.
Last edited by HissingSyd; 24th Dec 2020 at 13:00.
The maximum "rate of flap up" i.e. the vertical speed is reached at the end of upward cyclic component of the aerodynamic force that is controlled by the AoA, not at its peak.
The difference between those of us who are helicopter pilots and those who are theorists is that we get paid to do some of exciting stuff mentioned already on these pages, using our training and skills to complete demanding tasks in the machine we are given. As a result, most of use give little thought or worry as to whether the rotor is flapping or precessing (it is flapping btw) so much of your well-intentioned analysis is irrelevant beyond academia.
But don't take it to heart, keep on arguing your case - someone, somewhere cares.