How to calculate the size of small a jet drive from scratch?

Discussion in 'Jet Drives' started by Ngollins, Apr 7, 2010.

  1. Ngollins
    Joined: Apr 2010
    Posts: 1
    Likes: 1, Points: 0, Legacy Rep: 23
    Location: South England.

    Ngollins New Member

    I am wanting to construct from scratch a small jet drive unit for a tender. I have a couple of old lawn mower engines with about 3 hp, which i am hoping to use. The tender is only 5 foot long, would only have 2 or 3 adults in. I am not after high speed, just enough to potter about my local harbour come the summer. A prop would be the obvious answer here, but my local harbour is a mud hole, and im keen to learn about jet drive systems.

    Where do i begin to design the system bearing in mind all that is known is the input shaft power?

    Im not asking for an answer, just some guidelines or pointers I can then research into.

    Thanks in advance.

    1 person likes this.
  2. baeckmo
    Joined: Jun 2009
    Posts: 1,269
    Likes: 240, Points: 63, Legacy Rep: 1165
    Location: Sweden

    baeckmo Hydrodynamics

    Hi, Nathan, if you switch to the thread "Why a jet drive?", note #23, you will find an example of a simplified calculation procedure. There is a comparison with a propeller case included as well.
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