Propellor calculations

G

Guest

Guest
I'm interested in locating a source which provides calculations/formulae concerning propellor selection/pitch settings
to achieve optimum performance.
The variables I have am working with are Bukh DV 20 hp powering a 35 foot overall , LWL 29 feet, 6 ton displacement cruiser racer through a 2:1 V Drive
 

BarryH

Active member
Joined
31 Oct 2001
Messages
6,936
Location
Surrey
Visit site
Two companies i know of that have done it for me in the past, are Steel Developments and Lancing Marine, both of which i have found very helpful
 

PaulJ

Member
Joined
7 Jul 2001
Messages
695
Location
Ipswich
Visit site
Ian, I have a small programme that I downloaded from I can't remember where. If you send me your e-mail address through the "private message" system on this site I will send it to you. Alternatively, there is an excellent article in Nigel Calder's new book on calculating prop size. If you can tell me the rpm at which your engine develops it's 20hp it would only take a couple of minutes to work it out.
 
G

Guest

Guest
I have just bought a new prop for my boat. My calculations from basic principals gave 9.5 to 10 inches pitch. The commercial computer at one of the companies mentioned gave 12 inches, so I bought the one with 12 inches. The trial showed my calculations to be closer.

PropCalc gives two methods for pitch and the results are different. My experience indicates a separate calculation is more likely to be correct.

I could not find the programme on the westerly-owners web site. Can some one help please

Peter
 
Top