The design of an airplane to fly on Mars is difficult because the low density produces low damping, making the short period and Dutch roll modes problematic. Because of such uncertainties, NASA plans a flight test of the design very soon. To simulate the Mars atmosphere, the airplane will be dropped from a balloon 100,000 ft over Oregon. Your job is to design winglets and the tail to obtain desirable open-loop dynamic characteristics. The model should trim at a CL of about 0.7. It should have a stable short period mode and be stable in both Dutch Roll and spiral modes.
The properties of the drop-model are given below:
Mass: 40kg
Wing: Span = 16 ft, Aspect Ratio = 6, No dihedral.
Tail surfaces: Span less than the wing, but otherwise anything you like, AR=5, inverted V-tail with 30 deg anhedral.
Winglets: Span no more than 10% of the wing span. Any dihedral angle is OK.
Ignore the effect of the fuselage on the stability derivatives.
1. Experiment with winglet size and dihedral, and tail geometry with the LinAir program
in the notes. And select a design that appears to have reasonable dynamic response. Make a list of the airplane
stability derivatives and include the LinAir input file.
2. Assuming the wing is flat and untwisted estimate the required tail incidence to trim.
3. Make rough estimates of the airplane mass properties and evaluate its eigenvalues at 100,000 ft, trimmed at a CL of 0.7.