Thread: Discussion Efficiency of a ducted fan
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Old Jan 31, 2008, 12:15 PM
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Texas Buzzard
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McAllen,Texas
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Efficiency of a ducted fan

Is "effeciency " of a ducted fan standardized?

How is this measured by American Mfg?

I found the following in an add by GWS. Does it make sense?
Motor Volts (V): Amps (A): Thrust (g/oz): Power (W): Efficiency (g/W - oz/W):
EM400 (Stock) 7.2 6.6 147 / 5.19 55.44 2.65 / .09
EM400 (Stock) 8.4 7.9 170 / 6.00 75.84 2.24 / .08
EM400 (Stock) 9.6 9.3 210 / 7.41 100.44 2.09 / .07
EM400 (Stock) 10.8 11.2 246 / 8.68 134.40 1.83 / .07
EM400 (Stock) 12 12.5 281 / 9.91 165.00 1.70 / .06

If the Watts input to motor is measured to be ( 11v x 20 amps) = 240 Watts. And the test stand gave a measured thrust of 20 ounces, then o can we say effeciency is 0.08/Watt or about about 0.08 or 8% 8% is not good, eh?

Is this semi-valid? Thrust/Watt sounds good at first approximation.




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Last edited by Texas Buzzard; Jan 31, 2008 at 12:30 PM.
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