If I'm not mistaken, most of those parameters are used to help develop a figure for slip. While a large container ship might only see 5% at the 113 rpm
shaft speed, we in sailboats if spinning the screw in a direct configuration would expect to see 8%~18% slip, and all other calculations are straight forward if I remember my old classes
. prop pitch X RPM = inches per minute of speed / 12 = feet per minute X 60 = feet per hour / 6082 feet = nm/hr. So assume you are direct drive spinning a 21" pitch prop at 2000 rpm. 21" X 2000 rpm = 42000" per minute / 12 = 3500' per minute X 60 = 210000' per hour / 6082 = 35.4 kt X .82 slip = 28.3 kt That seems fast for the rpm, maybe there is more slip than my range of 8%~18%.
Do you get 28 kt at 2000 rpm? Seems fast. Are you using a gear
reduction? If so, what is the ratio?
I hope I still remembered how to do this, if not I know David M knows.
I think the last container ship I was on had a 21' pitch and at full ahead sea speed was turning at 113 rpm. 21' X 113 = 2373 X 60 = 142380 / 6082 = 23.4 kt X .96 = 22.4 kt, it was a fast ship.