So for background, let's say that the higher the thrust a motor/propeller combination provides the less efficient it is.
I was sitting here with some charts that gave the thrust and thrust/W figures for a certain propeller-motor combination. I wanted a 2:1 thrust:weight ratio so it could actually maneuever, so I was about to take the voltage with the best thrust/W (ie. choose batteries that would provide said voltage at full throttle) and make everything weight 1/2 that max efficiency thrust.
But then I started thinking...hmmm it'd be nice to get more weight on the thing and maintain run-time. BUt that means higher voltage batteries which means more thrust but reduced efficiency, and also less run-time for the same batteries. So I say down and calculated it out and it seems that by increasing the batteries voltage (for more thrust) and capacity (for same run time as before due to increased current at higher voltages) I can get 8x as much thrust as the battery weight that will be added on.
But the efficiency is now less. But that's a moot point right? Because the max efficiency will now occur at around hover and only be reduced during big maneuvers (whereas before it occured during the most extreme of maneuvers since I took the max efficiency thrust and made the unit weight 1/2 the peak efficiency thrust).
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So basically, should a helicopter electric drive be sized so it is most efficienct at hover, or during hard maneuevers? If I wanted it to be most efficient during motion then I'd have gotten a plane right? (which is more efficient at its most demanding maneuever than an equivelant helicopter at its least demanding).
I'm just looking for people's opinions here.