Dave,
This thread left me with an uneasy feeling that we might still be talking at cross-purposes. I'm probably doing my usual trick and tieing my shoelaces together, to stop myself running away...
Prouty say (P17, Chap 1):
Ct/Sigma = Thrust / ( Air_Density * Blade_Area * Tip_Vel^2 * Radius^2 )
Me say:
This means that if the blade area is increased for a larger span of same radius, the tip vel will come down as expected. So even for a future counterrotating rotorcraft Ct will still be optimum at 0.125.
That means that the FM vs Ct/Sigma curve still peaks at Ct 0.125. This means that rotor power is not a function of bladespan.
Is this right, or did i miss something? Don't want a Comanche bearing down on me to have the last word!
Mart