Question

The formula for velocity of maximum specific air range is __________

(a) \(\big[\frac{3-n}{1+n}\big]^{\frac{1}{4}}\)

(b) \(\big[\frac{3-n}{1+n}\big]^{\frac{1}{3}}\)Vmd

(c) \(\big[\frac{3-n}{1+n}\big]^{\frac{1}{4}}\)Vmd

(d) \(\big[\frac{3+n}{1+n}\big]^{\frac{1}{4}}\)Vmd

I have been asked this question in an online interview.

My query is from Cruising Performance topic in portion Cruising Performance of Aircraft Performance

Answer 1

Correct answer is (c) \(\big[\frac{3-n}{1+n}\big]^{\frac{1}{4}}\)Vmd

The best I can explain: The formula for velocity of maximum specific air range is  \(\big[\frac{3-n}{1+n}\big]^{\frac{1}{4}}\)Vmd where ‘n’ is the exponent and Vmd is maximum velocity. The value of ‘n’ depends on the value of bypass ratio of the engine. This implies that as the value of ‘n’ increases the bypass ratio increases.