The geometric data collected from the nine propellers shows that the average effective radius of the blade that produces lift is approximately 86% of the total propeller radius
, which includes hub losses.
The forces acting on a small section of the blade are determined and then integrated over the propeller radius
in order to predict the thrust, torque and power characteristics of the propeller.
As propeller radius
[R.sub.P] = 0.25[b.sub.wing] = 0.25 [square root of (S x AR)], substituting propeller disk area A = [pi][R.sup.2.sub.P] into (23) then we yield a more specific version of the reference velocity as