Modifying a water jet for passages (Different design point)

Discussion in 'Jet Drives' started by MechaNik, Jun 29, 2012.

  1. MechaNik
    Joined: Jan 2011
    Posts: 139
    Likes: 5, Points: 0, Legacy Rep: 62
    Location: Greece, Italy

    MechaNik Senior Member

    I am not looking for variable geometry water jet or any such nonsense or permanently changing the set-up.

    What I am asking is if it is possible to temporarily set up a sprint vessels water jet system to perform better on a long passage, hopefully with only minor changes to inlet and outlet diameters. The design point was around 55 knots but for a passage 18 knots on the plane or 10 knots displacement speed would be needed.

    Propulsion efficiencies where calculated to be 28% at 10knots and 35% at 20knots so it would seem there is room for improvement, but not that it's realistic.

    I assumed that more inlet flow would be needed and the only idea I could come up with is a removable moulded skirt on the inlet duct lip (slight scoop)?
  2. baeckmo
    Joined: Jun 2009
    Posts: 1,269
    Likes: 240, Points: 63, Legacy Rep: 1165
    Location: Sweden

    baeckmo Hydrodynamics

    Might be possible, depending on "as built" status. Send me a mail with all relevant info on hull, engines and jets; i'll see what can be done without a complete rebuild.
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