Question

The advanced ratio is given by _______________

(a) J=\(\frac{D}{nV}\)

(b) J=\(\frac{nV}{D}\)

(c) J=\(\frac{V}{nD}\)

(d) J=\(\frac{n}{VD}\)

I got this question during an online exam.

My question is from Climb and Descent Performance with Mixed Power Plants in section Climb and Descent Performance of Aircraft Performance

Answer 1

Right choice is (c) J=\(\frac{V}{nD}\)

The explanation: The advanced ratio is given by J=\(\frac{V}{nD}\) where J is advance ratio, V is velocity and D is propeller diameter and n is rotational speed. Propeller efficiency is depended on advanced ratio.