PFR - Aerospace Engineering Sciences Senior Design Projects ...

Project Final Report – CUDBF April 30 th , 2009
ASEN 4028: Aerospace Senior Projects
8.0 Mechanical Design Elements
Author: Shivali Bidaiah
Co-Author: Ben Kemper, Mark Findley
8.1 Aerodynamics Mechanical Design Elements
8.1.1 Aircraft Geometry
The analysis that was done on the effect of static margin with varying sweep angles and varying
taper was used to determine the optimal geometry given the requirement for the aircraft to fit in
the box. In order to have the most room along the wing for control surfaces, the span was chosen
to be 68 inches. This satisfies the minimum wing span requirement of 60 inches. Figure 33
shows the aircraft geometry:
Figure 33: Aircraft Geometry
The analysis done showed that the static margin increased as the sweep angle increased between
20 and 25 degrees. The best possible configuration that meets the requirement to fit in a 4’x2’x2’
box is a leading edge sweep angle of 23 degrees and a taper ratio of 0.5.
Because this project involves flight missions with asymmetric loading in the lateral direction, the
addition of a vertical is necessary. The vertical is the equivalent of a vertical stabilizer and
provides yaw control. Winglets were added to each wing tip to serve the purpose of a vertical
stabilizer. The winglets were sized using the tail volume coefficient method.
The tail volume coefficient method is based off of the sizing of past aircraft. This sizing is based
off of the area of the wing, S w , the wing span, b, the area of the vertical tail, A vt , and the distance
between the c. g. of the aircraft and the aerodynamic center of the vertical tail. The tail volume
coefficient for most aircraft falls in the range of 0.03 to 0.06. A larger tail volume coefficient
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