Unified Engineering                                                                           Spring Term 2006

Problem P4. (Propulsion) L.O.’s C & D

Determine the maximum endurance as a function of turning radius for a small electric-powered airplane.  Professor Drela provided the following parameters for a Plain Vanilla version of the aircraft you are designing for the spring Systems Problems:

Battery energy, E = 8500 J

Aircraft weight, W = 3.3 N

Wing area, S = 0.225 m^2

Wing span, b = 1.50 m  (AR = 10.0)

Lift coefficient, CL = 0.9  (endurance cruise)

Zero lift drag coefficient, CDAo/S + cd = 0.048         [called CDo in the propulsion notes]

Overall efficiency, h = hmhp = TV/Pelec= 0.25

For a range of bank angles, f = 0 …45 degrees, determine and plot turning radius (r), the velocity (V), the rate of energy usage (Pelec), and the flight time (t).

[You may find it helpful to refer to both the SP1 lecture notes and the Propulsion lecture notes.]