Answer Happy

Proof how ( 1 ) become ( 2 ) .
1 2 C-(1+3)(1-0) Cp Vd 1+ = 1 2 ν v Vd To find the maximum possible rotor efficiency, we simply take the derivative of above equation with respect to and set it equal to zero: dcp 1 0 = 그 3 d ν Vd = a vd = V ν This conclusion, that the maximum theoretical efficiency of a rotor is 59.3%, is called the Betz efficiency or, sometimes, Betz' law.