ORIGINAL: beppeVRCS
My 2 cents is that you use a three blade prop (apart from look and scale requirements) when you do not have enough clearance for a 2 blade prop... increasing the number of blades decreases efficiency. Sophisticated high efficiency systems have one blade only!
Beppe
Efficiency is measured how?
The only time the blades are turning in the previous blades' wake is when the plane is on the ground. True for single blades too.
Even at moderate speed of 60 mph, at the typical rpm we turn, 3 bladed props work well and each blade bites new air. Agree on the clearance and quietness. 3 blades will load the engine more and that load will delay acceleration a bit