Question

7 2) An aircraft has a Breguet range of 12,000 km when the mass of fuel burned is one third 8 of its initial gross mass. 9 What is the correct formula for the Breguet range? And what would be the range when O the initial fuel mass is halved and all other parameters remain the same. 11 Note: the units of QF are J/N [2 marks] 12 43 44 45 46 47 48 49 A) n. QF In {Minitial( Minitial-Mfuel burned) } B) (npQF) (L/D) exp {Minitial ( Minitial-Mfuel burned)} C) QF (L/D) In {Minitial ( Minitial-Mfuel burned) } D) n. QF (L/D) In {( Minitial-Mtuel burned ) /Minitial} E) n. Q: (L/D) In {Minitiail( Minitial-Mfuel burned ) } F) none of the above A) 4,345 km B) 5,396 km C) 6,000 km D) 12,000 km E) 3,677 km F) none of the above : actual value

Answer 1

Given Range = 12000km; mass of fuel burned one third of initial gross man Breguet Range fuel consumption rate fa -dW fuel at Overal weight of aircraft changes as fuel burns so dW fuel = d W aircraft Edw → Fa dw at o Now, dWFuel -F d W Fuel dt dR dR dt where di V = speed of aircraft Now, Range RE v(&) dt ti From O put at = 3/4 and change the integration range from ti ,t, to w,,We

3 - R: S - ř dw . WI Mp= Propulsive efficiency Cp- specific fuel consumption (N/5) Cpa tor where, Now, P = nppe Pa Thrust Pe= Power output from engine F = Cp Pe Power Force X velocity Lift drag ratio D pa Xv 은) w W = weight of aircraft From 3 R P. (a) .dw Pe . Cp W2 pf dw il W.G Pe ६

Also P = np Pe d me Cp E ) ( 4 ) wi RE en / w 2 me се (w) Wz wi V RE no ( ). com Co en R = np. Of (6) Minitial Minitial - M fuel burned

Now; R = 12000km Full burned a Minitial 3 finally R22. Minitial = half of Minitial 1. Minitial A L en 12000 = np Of Minitial 1 Minitial 3 Minitial B L en Ra np Of دانے Minitial Minitial NI 2 New range, from A and B , R = 12000 km (0)