Converting Thrust into PSI...Way over my head

Discussion in 'Jet Drives' started by Zac Penn, Apr 6, 2018.

  1. Zac Penn
    Joined: Nov 2015
    Posts: 27
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    Location: Jacksonville, FL

    Zac Penn Junior Member

    I have tried searching and the formula for Thrust it too complicated for me to convert it the way I want.
    Here is my objective and maybe you will get a better understanding of what I want...
    I want to retro-fit a ROV underwater thruster and turn it into a submersible axial flow water pump to use on a koi pond. The filtration will create a few feet of head pressure and I need to know how much thrust is required from the thruster to overcome this head loss.
    In an ideal world I would like the conversion formula written out for me so I can plug in different values and compare thrusters.
    I would love to achieve 10,000 GPH at 3' of H2O (1.3 PSI) so I need to know how I can convert thrust produced into that output.

    Thanks in advance!
  2. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    rwatson Senior Member

  3. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    That is a textbook approach, and doesn't take into account design efficiency. Usually, those are published values from the manufacturer. Otherwise you have to test it. Further, thrust, pressure and flow are related but not linearly. There are also operational limits to where the equations can be applied. An ROV thruster is not designed for the service you are proposing. A centrifugal submerged pump would do better. The thruster is most probably going to cavitate.
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