Question

Which of the following represents range function?

(a) \(\Big[\frac{V_{mdi}}{C}E_{max}\Big]\)lnω

(b) \(\Big[\frac{V_{max}}{C}E_{max}\Big]\)lnω

(c) \(\Big\{\frac{2u^3}{u^4+1}\Big\}\)lnω

(d) \(\Big\{\frac{2u^4}{u^4+1}\Big\}\)lnω

I got this question in final exam.

I need to ask this question from Cruise Method 1 topic in chapter Cruising Performance of Aircraft Performance

Answer 1

The correct option is (c) \(\Big\{\frac{2u^3}{u^4+1}\Big\}\)lnω

For explanation I would say: The range function is given by \(\Big\{\frac{2u^3}{u^4+1}\Big\}\)lnω. The range equation in cruise method 1 is given by R1=\(\Big[\frac{V_{mdi}}{C}E_{max}\Big]\Big\{\frac{2u^3}{u^4+1}\Big\}\)lnω where V is true airspeed, C is specific fuel consumption, L is lift, D is drag, Emax is endurance, u is relative airspeed and ω is fuel ratio.