Propeller Performance 23 Mar 06
Lab 7 Lecture Notes A
Propellers tested
Tests were performed on a Speed-280 motor driving the following propellers:
APC 5.1 x 4.5
APC 5.5 x 4.5
APC 6.0 x 4.0
APC 7.0 x 4.0 (narrowed)
APC 7.0 x 5.0 (narrowed)
The tests were performed over a range of air velocities and motor power levels, the latter
controlled via motor voltage. Measurements consisted of thrust, t orque, RPM, current, voltage.
This allowed the calculation of all relevant operating parameters and efficiencies.
Figure 1 shows typical thrust performance measurements for four applied voltages, together
with predictions from the motor/prop simulation model.
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 5 10 15 20 25
T [N]
3 Volt
4 Volt
5 Volt
7 Volt
V [m/s]
Figure 1: Measured thrust versus velocity (symbols), for APC 5.1x4.5 prop, Speed-280 motor.
Lines are motor/prop numerical model predictions.
The intent here is to validate the numerical model, which is used to generate all the subsequent
performance curves.
Maximum-Power Thrust
Figure 2 shows the thrust of the propellers for the maximum available battery rest voltage of
7.4 Volts (the actual battery voltage is reduced somewhat by battery’s internal resistance).
Figure 3 shows the corresponding maximum thrust power.
Pmax ≡ TmaxV = ηm ηp ηb (Pelec)max
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