PFR - Aerospace Engineering Sciences Senior Design Projects ...

Project Final Report – CUDBF April 30 th , 2009
ASEN 4028: Aerospace Senior Projects
12” propeller without any additional landing gear size and weight. Propeller sizes up to 14” in
diameter were tested incase additional thrust was needed, since the takeoff incidence angle
allows for propellers of up to 14”. A motor was run at 800W, the maximum theoretical power
that could be delivered by the battery pack to each motor (20V and 40 amps per motor, or 80
amps total).
Table 25: Static Thrust Test Results
Propeller Diameter (in) Propeller Pitch Maximum Thrust (lb)
12 6 5.37
12 12 4.30
13 6.5 5.06
13 10 4.78
14 7 5.87
14 12 4.65
This test confirms the expected result that higher diameter propellers as well as lower pitch
propellers produce more static thrust than lower diameter and higher pitch propellers. In order to
get the required thrust of 8.0lbs of static thrust at 1200W, each motor must produce 5.33 lbs of
thrust at 800W. Therefore, this test confirms that the only usable propellers are 12in x 6 and 14in
x 7 propellers.
13.1.2.2 Battery Endurance Testing
In order to determine aircraft endurance, the battery pack was discharged on the ground in a
mission profile similar to the aircraft when in flight. It was determined that mission two,
described in 2.2, would require the most battery endurance since the aircraft will be carrying the
weight of the full water bottle load for four laps. In order to simulate this mission, the battery
was first discharged at full power for ten seconds to simulate takeoff. The power was then cut in
half for an additional ten seconds to simulate climb, and then reduced to cruise power until the
battery pack voltage dropped below 0.9V per cell. The battery pack used in this test can be seen
in Figure 112.
Figure 112: Competition Battery Packs
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