finding thrust

Discussion in 'Powerboats' started by scott steffe, Feb 16, 2007.

  1. scott steffe
    Joined: Jan 2007
    Posts: 26
    Likes: 1, Points: 0, Legacy Rep: 13
    Location: port charlotte fl

    scott steffe Junior Member

    how would one figure out the trust power of a v 6 outboard say 300 horse power
    anyone ??
     
    scott steffe, Feb 16, 2007
    #1
  2. jehardiman
    Joined: Aug 2004
    Posts: 3,773
    Likes: 1,167, Points: 113, Legacy Rep: 2040
    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    Without prop data it is impossible. Rules of thumb say maximum thrust of 20-30# thrust per shp @ 0 speed and maximum rpm (n) dependent on delivered torque, falling off at some factor (dependant on the prop pitch to diameter and n^2) with the advance coefficient J= Va/nD. Usually, for most P/D ratios, thrust =0 at J ~ P/D.
     
    jehardiman, Feb 16, 2007
    #2
  3. scott steffe
    Joined: Jan 2007
    Posts: 26
    Likes: 1, Points: 0, Legacy Rep: 13
    Location: port charlotte fl

    scott steffe Junior Member

    so lets see if i get this
    so using a prop caculater for speed you are figuring thrust ?
    14x32 cleaver @ 6000 rpm = 145 mph or so giving what thrust ratio per lb
    so what would be the trust power needed to turn that prop @ 2500 rpm
    300/500/ 600lbs or more
     
    scott steffe, Feb 17, 2007
    #3
Loading...
Similar Threads
  1. cheetahmike

    Outboard Engine Thrust

    cheetahmike, Sep 30, 2012, in forum: Powerboats
    Replies:
    43
    Views:
    14,061
    tunnels
    Oct 14, 2012
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.