Hi. I am working on a two rotor design with the hopes of having some efficiency gains by using two larger rotors. I have always heard that fewer larger rotors are more efficient than more, smaller rotors and took that for granted. Now that I am actually exploring the idea, I am finding it hard to justify. It seems that disk loading is the major factor and not individual disk size. For example, a 12 inch rotor will fit inside of a 12x12 inch area, and so will four, 6 inch rotors. The problem is that the single 12 inch and the four 6 inch rotors have the exact same amount of disk area, and both fit into the same 12x12 inch area. Messing around on ecalc seems to verify similar hover efficiency between the two.
So my question is, where am I going wrong here? Is my math bad? Is disk loading the main factor and one large rotor is not any more efficient that four smaller ones as long as disk area is the same? Any help or insight would be greatly appreciated...
Replies