No; I would not expect the chord of a gyroplane rotor blade to change chord from the root to the tip.Why majority of the rotor blades have a constant chord from the root to the tip? Since the air speed variation root is highest, you would expect that region will have a shorter chord, no?
Long hub bars are the closest you are likely to see to a small chord at the root, but there has been a fair bit of work on tip shapes for helicopters.
Optimising twist is usually worth the effort but chord variation doesn't pay off as well.
We better worry flow separations on the rear parts of the fuselage. Much more to gain with less research.
Unfortunately, we look only the cosmetic of nose .
Are you sure that everything is done to avoid the separations of the flow behind the pod?The only way to deal with post fuselage separations is with a tail.
Cavalon, Calidus, Magni Orion ELA Eclipse and the various iterations of the Xeon all make efforts to manage airflow at the rear.Still, majority of the drag is coming from the rotor. Not much you can do about that.
Regarding separations. Most gyros did little if any at all about separantions. This is an exception
Cavalon, Calidus, Magni Orion ELA Eclipse and the various iterations of the Xeon all make efforts to manage airflow at the rear.
As the speed picks up a greater portion of drag comes from parasitic drag.
It appears to me at 85kts less than thirty percent of the total aerodynamic drag comes from the rotor in the gyroplane I fly (The Predator).
This is only true for an FW, but false for a gyro because the profile power of a rotor keep almost constant .Just for comparison... IIRC, at optimal L/D, induced and parasitic drags are equal.
(It's all 'in the book' the reference of which I gave above. Pages 112-113...)
The power required to cause the rotor to auto rotate is significant. I wish there is a way to determine that.
Vance, thanks in advance. I would like to experiement with different number. I will private post my email to you.
This is only true for an FW, but false for a gyro because the profile power of a rotor keep almost constant .
In my opinion, relying on the cD min of 8H12 measured in a wind tunnel with low turbulence, H. Dudda underestimates the drag of the rotors . Thus, to justify the power absorbed in level flight, it overestimates the parasitic drag.