prop calculator

Discussion in 'Boat Design' started by kapnD, May 18, 2003.

  1. kapnD
    Joined: Jan 2003
    Posts: 759
    Likes: 104, Points: 43, Legacy Rep: 40
    Location: hawaii, usa

    kapnD Senior Member

    does anyone know of a prop calculator (online, preferably) that will allow a dummy like myself to experiment with variables and achieve reasonable figures?
    Surfbaud is the only one I can find, and it doesnt seem to be working, or maybe it doesnt like my computer!
    Im recessing the prop into a pocket, will this have any effect on my calculations?
    mahalo, KapnD
     
  2. dougfrolich
    Joined: Nov 2002
    Posts: 661
    Likes: 21, Points: 28, Legacy Rep: 225
    Location: San Francisco

    dougfrolich Senior Member

    I would suggest the propeller handbook by Dave Gerr.

    Doug Frolich
     
  3. ISLNDMRN
    Joined: Dec 2002
    Posts: 7
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: LONG ISLAND NY

    ISLNDMRN Junior Member

  4. Guest

    Guest Guest

    PSOP

    SNAME (http;//www.sname.org) has a propeller program for sale called "PSOP".

    Note also that the Bp-delta diagram in Gerr's book is for Waginengen B series props. Use of this data on segmental props (more typical of stock propellers) will tend to result in overpitching.

    The SNAME program has both B and segmental series data.
     
  5. Dim
    Joined: May 2003
    Posts: 315
    Likes: 3, Points: 0, Legacy Rep: 114
    Location: somewhere

    Dim Senior Member

    Attached Files:

    1 person likes this.
  6. Dim
    Joined: May 2003
    Posts: 315
    Likes: 3, Points: 0, Legacy Rep: 114
    Location: somewhere

    Dim Senior Member

  7. Guest

    Guest Guest

  8. lancingmike
    Joined: Sep 2008
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: portslade, england

    lancingmike New Member

    Propeller Design Program

    If you care to E-mail me a sample set of data:-
    Total laden weight
    Waterline length
    Number of engines
    HP
    RPM
    Gear reduction ratio

    I will do you a sample calculation on my program which is available to buy.
     
  9. kapnD
    Joined: Jan 2003
    Posts: 759
    Likes: 104, Points: 43, Legacy Rep: 40
    Location: hawaii, usa

    kapnD Senior Member

    Wow, this is an old thread! I have learned a lot in the time since I first posted it, and have used lots of different prop calculators. To answer my own question, one of the best is on boatdiesel.com, and though it does require a paid membership to use it, is well worth the $25. There is a wealth of other information also, and a rich forum complete with resident gurus, much like this one. Don
     
  10. Brent Swain
    Joined: Mar 2002
    Posts: 951
    Likes: 35, Points: 0, Legacy Rep: -12
    Location: British Columbia

    Brent Swain Member

    Prop

    Skenes elements of Yacht design has a chart that I use for diameter. For pitch it is simple calculator math.A 12 inch pitch gives you one ft per rev. Multiply this by 60 and you have ft per minute, Multiply this by 60 and you have ft per hour . Divide this by the number of feet in a nautical mile and you have knots per hour .
    Adjust for slippage ( around 50% for sailboats) and you have knots. Compare with other boats to find how many knots you can expect for your type of boat, and the same HP and you have what you are looking for . Divide by 12 , then multiply by 11 to find what you could expect from a 11 inch pitch , etc etc trial and error.
    My book explains this, as well as measureing the pitch on any prop, and changing it, balancing a prop, etc.
    Brent
     

  11. lancingmike
    Joined: Sep 2008
    Posts: 4
    Likes: 0, Points: 0, Legacy Rep: 10
    Location: portslade, england

    lancingmike New Member

    There was a certain amount of cooperation between me and boatdiesel.com when his program was written, so I am well aware of it.
    We use slightly different approaches to achieve the required results.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.