Hi,

The definition for propulsive efficiency is thrust * velocity / power input. This formula works for fixed wing as well as flapping wing.

So what if the plane or aircraft is hovering? How do you define its efficiency? Or what type of efficiency can be defined? Is it hovering efficiency?

Lastly, is the formula applicable to both helicopters n flapping MAV?

thanks

Hi Zonexo, During hovering flight, the efficiency = (avg. Lift/avg Drag). For a hovering flight, it is obvious that avg drag=0. So we must take avg drag over one half stroke. It must be pointed out that this definition is applicable only for flapping on a horizontal stroke plane.