Answer Happy

Consider a light, single-engine, propeller airplane. The airplane weight is 15000 N and the wing reference area is 17 m2. The drag coefficient CD of the airplane is a function of the lift coefficient CL, this function is CD= 0.025+0.054 C12. a) For a steady, level flight at 1000 ft altitude, plot on a single graph the variation of Cl, CD and the lift-to-drag ratio L/D with flight velocity ranging between 10 m/s and 100 m/s. b) Make some observations about the variation of each quantity with velocity c) Consider a similar airplane (Airplane-2) with same weight of 15000 N and a wing reference area of 20 m2 flying at the same altitude. Considering the same range of velocity (from 10 m/s to 100 m/s), which airplane has a better aerodynamic efficiency (L/D)? Prove your answer by calculation. d) Consider the airplane in part a (Airplane-1) with the same design parameters of weight (15000 N) and wing area (17 m²), but with a clockwise rotating circular cylinder (diameter = 1 m) to be integrated in the wing, which has a weight of 1000 N, drag coefficient of 0.6 and a maximum velocity on the surface of the cylinder of 75 m/s. This airplane can be denoted by (airpane-3). plot on a single graph the variation of Cl, Cp and the lift-to-drag ratio L/D with flight velocity ranging between 10 m/s and 100 m/s. Comment on the results of variation of each quantity with velocity. e) Repeat part (d) but with a maximum velocity on the surface of the cylinder of 150 m/s (twice the value in part d). Compare the results of the aerodynamic efficiency (L/D) with that obtained in part (d). What is the reason behind the different results if any?