Question 1: What do you understand by the term aircraft and airplane? Explain different classes of aircraft and categorization of airplanes.
Question 2: Define the term ISA. Compute pressure, density and temperature at altitudes of 9.5 km and 18.5 km. Explain the benefits of using indicated air speed over true air speed with an illustration in each case.
Question 3:
a) Find out the location of aerodynamic centre in terms of chord of an airfoil, form wing tunnel data as shown below:
At Cλ = 0, Cmc/4 = 0.04
At α = 8o, Cmc/4 = 0.10, Cl = 1.0, Cd = 0.06
b) Describe with sketches/plots, the effect of sweep back on the lifting characteristics of a wing as compared with that for a straight wing.
Question 4: An aircraft is flying at a certain altitude at a Mach No of 0.85. The outside air temperature is 232 K. At a given point on the upper surface of the wing, pressure and temperature are 20100 N/m2 and 221K. Determine the pressure coefficient at this point? If this pressure coefficient is average for the upper surface and if average pressure coefficient for lower surface is half in magnitude and of opposite in sign, find out the air foil lift coefficient. If wing area is 327 m2, find out the lift.
Question 5: An airplane weighing 100 000 N has wing span = 19.5 m, wing plan form area = 45 m2 with each of the two jet engines developing 16.5000 N of thrust. Assuming CDO = 0.02 and e = 0.80, plot the variation of power and thrust with velocity. Thus obtain Pmin and Tmin needed for straight and level flight. Can you verify your answer?