This answer is excellent:-
except that it is (in practice) unusable, since all the units are missing.
I'm guessing we use meters for length (prop diameter), and watts for power.
I'm not sure what units we use for mass (grams or kilograms?) - but either way - neither of those work (grams gives answers 10x too small, and kg gives answers 1000x too large).
- I have a 10,000 watt motor
- My propeller is 1.25meters diameter
- At full pelt, using bathroom scales on the wall, it pushes me with 35kg force
Using 0.8 for the prop efficiency, and 0.9 for the motor efficiency, and 1.225 grams/l for normal air density, the referenced formula gives 367448 grams thrust - 10 times too much.
So yeah... what are all the units supposed to be?