Conversation

@nflux IIRC the reason that fans usually have an odd number of blades is that you want the number of blades and the number of struts fixing the fan hub to the casing to be coprime to each other, because that spreads out the acoustic emergy of the fan blades passing the struts the widest and avoids concentrating it into a single noisy tone.

For a freestanding wind turbine that should not matter.