One thing I was specifically looking for when datalogging is propeller efficiency...
The problem with the math is that it is missing an accurate pitch value. Most props used today have some progressive pitch, and all have some cupping on the trailing edge. So what is the effective pitch, that which ‘supplies the thrust’? If you bother to actually measure the blade pitch at several points with a pitch gauge you’d realize this problem - you cannot always trust the nominal pitch values listed by the prop maker.
Too, props are not screws, they can build thrust by the difference in pressure between the face and back of the blade, making blade shape and cross section as important as the pitch value. These facts make all those pretty calculated “efficiency” values pretty meaningless.
In reality who cares about the true pitch (whatever that means), it is the performance of the boat which matters. I spend my time maximizing overall boat performance, not worrying about some unknowable value for an equation. But it’s your time, spend it how you want....
.
ERROR 403 - This is not the page you are looking for
Bookmarks