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I am using momentum theory to estimate power needed for an eVTOL. I have read past papers where the results got from momentum theory was direcly use to estimate the power needed from the battery. How it that possible?

Should we account for drivetrain and propulsion efficiency (and divide the result got from momentum result by the efficiency to find the real power output needed from the battery)?

P Ek
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1 Answers1

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Yes we should, and fortunately there have been measurements to check how the momentum theory stacks up with reality.

enter image description here

The pic above was also used in this answer and shows the methodology for helicopters, where an extra loss factor of 1.15 seems to generate a good match. This answer provides some more details on computation of thrust from ducted fans, which I presume the eVTOL has.

Koyovis
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