Keppe engine: smoky or awesome?

[Forhorse]

Ah I just saw that it is not 1.48 that it finds but 1.148, finally not serious considering that I do not find the same result anyway.

[Capt_Maloche]

The good question is: is there already an improvement?

because an engine efficiency is around 90% in general, see 95% for large models

Afterwards, the efficiency of a propeller is rather bad, of the order of 30 to 50% for small plastic sizes and 70% for the best in aeronautics.

I'm skeptical, like the pit

[J Greef]

Hello,

You seem to be having trouble recalculating engine performance as shown in this video. It's still very easy.

Electric power = current x voltage = 0.034 A x 203 V

Mechanical power = torque x velocity
with:
Torque = force x arm = mass x 9.81 x arm = 0.042 kg x 9.81 x 0.2 m
velocity (angular: rad / sec) = 2 x PI x rpm / 60

In short the equal yield (0.042 x 9.81 x 0.2 x 2 x PI * 920) / (60 x 0.034 x 203) = +/- 1.15

Conclusion: if their basic data is correct, the yield obtained is effectively> 100% (ie: there are no errors in the calculation).

[Forhorse]

Hello,

You seem to be having trouble recalculating engine performance as shown in this video. It's still very easy.

Electric power = current x voltage = 0.034 A x 203 V

Mechanical power = torque x velocity
with:
Torque = force x arm = mass x 9.81 x arm = 0.042 kg x 9.81 x 0.2 m
velocity (angular: rad / sec) = 2 x PI x rpm / 60

In short the equal yield (0.042 x 9.81 x 0.2 x 2 x PI * 920) / (60 x 0.034 x 203) = +/- 1.15

Conclusion: if their basic data is correct, the yield obtained is effectively> 100% (ie: there are no errors in the calculation).

The only difference between your calculation and mine is that I rounded gravity to 10 when you took its real value of 9.81, hence the difference in result (me 117%)
And we show in passing that a variation of 0.19 in one of the variables already leads to a variation of 2% on the result. Like what the sum of all measurement errors (taken a little hard) can very well lead to this extraordinary performance.

Finally me what I criticized at the beginning is especially the way in which their calculation is posed, because even if the result is exact, the equation is completely false for the calculation of a return.

[J Greef]

in Forhorse,

You write that "the equation is completely wrong for calculating a yield". So in your opinion, which equation should we use in such a case?
Since they calculated the output as = mechanical power / absorbed electrical power, I don't see any errors. Am I wrong ?

[Forhorse]

in Forhorse,

You write that "the equation is completely wrong for calculating a yield". So in your opinion, which equation should we use in such a case?
Since they calculated the output as = mechanical power / absorbed electrical power, I don't see any errors. Am I wrong ?

Well yours is very good.
But surely not the one they pose in the video this one is nonsense. I still haven't understood how he finds 1.148 with this equation, and especially why he poses this one instead of asking the correct one.

[J Greef]

The efficiency of this Keppe motor in basic configuration is not too bad but much lower than the yields of conventional industrial electric motors (which are above 90% as mentioned by Capt_Maloche).
If they claim that with this engine we could achieve very significant savings they compare with small electric motors which have a deplorable performance. They explained it well on their forum and there is also a copy of this explanation under the following link (at the bottom of this page, post of 30 April):

http://www.overunity.com/index.php?PHPS ... 0#lastPost

Le forum Keppe:
http://keppemotorclub.bestforumpro.com/forum.htm