ORIGINAL: blw
The original hitch began when prop velocity was being talked about and it became mixed up with airspeed. Konrad, you got those confused way back in one of your arguments.
The use of a single thrust chart seems inaccurate. One way to simply prove it is to ask if it means glass filled props or wooden. They certainly aren't the same. I'm looking at a chart now that shows 0.6 pitch wood props with more static thrust and thrust at airspeeds over ones with greater pitch.
RPM and prop diameter has more to do with prop efficiency than pitch.
Konrad
A rotor like that found on helicopters is more efficient for hovering.
Helicopter guys are laughing now. Hovering requires more power than any mode of flight! That explains why there are things like effective translational lift and transverse flow effect when accelerating from hovering flight. This is just the basics of helicopter flight, and not advanced by any stretch. If you look any of it up you will see where you would have to retract that statement.
Thank you BLW,
In post #4 the OP asked about thrust to weight ratio. He gave no other modifier. I took it to mean static thrust as measured by most novices to these issues. As the OP did not dispute this assumption on my part I assume we are taking apples to apples.
OK, you got me on the prop material issue. What does this have to do with things? A composite prop can be made thinner (stiffer for the same cross section) and as a result use that thinner more efficient airfoil. But if the experiment is framed properly all variable under control there is no benefit to a composite prop if it is the same size in all dimensions. OK these is some benefit to the stiffer prop as it holds its shape better. To realize this you must spin the prop faster. But the benefit of a stiffer prop isn't realized until the cross section is made smaller allowing it to spin faster for a given power. This is why my FAI props are cast of carbon fiber and allowed to spin near 30K rpm in flight.
As for a heli needing a lot more power in hover than in forward flight that is very true. If you read my post I hope I said that our airplane prop takes a lot more power to hover than a helicopter rotor. Again this is in hover. As we go into fast forward flight the prop becomes the preferred propulsion method if for no other reason than the trailing rotor blade issue. I see no need to retract anything. You are quoting me out of context. Did I miss anything?
All the best,
Konrad
P.S.
As I read the OP's question he is making the assumption that the four cycle engine has more thrust for any given power. This is false as it is the prop not the engine that make thrust. Now statically the four cycle will appear to give more thrust as it is often attached to a larger diameter prop. But at speed this changes very rapidly.
So I have to ask the OP, is BLW correct in that I mis-understood your question?