Question

What is the propeller advance ratio for the power-producing powerplant when the true airspeed is 300m/s and the diameter of propeller is 0.5 m with rotational speed of 117.81rad/sec?

(a) 7.01

(b) 9.02

(c) 5.09

(d) 5.89

The question was posed to me in class test.

The above asked question is from Power Producing Power Plant in section Aircraft Force Systems and the Equations of Motion of Aircraft Performance

Answer 1

Right option is (c) 5.09

The explanation is: The answer is 5.09 radian. Given advance ratio V=300m/s , n=117.81rad/sec, D=0.5 m. From the equation J=\(\frac{V}{nD}\) we can find propeller advance ratio. Substitute the given values in the equation J=\(\frac{300}{117.81*0.5}\)

On solving J=5.09 radian.