nozzle and intake efficiency calculation

Discussion in 'Jet Drives' started by tsuji_kenji, Apr 13, 2012.

  1. tsuji_kenji
    Joined: Jan 2011
    Posts: 16
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    Location: malaysia

    tsuji_kenji Junior Member

    i have a problem to calculate the efficiency at the nozzle and intake at waterjet. in my past reading, to calculate the head losses at intake and nozzle,i must know the efficiency at the both side. OR,i easily can estimate that efficiency?
  2. baeckmo
    Joined: Jun 2009
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    Location: Sweden

    baeckmo Hydrodynamics

    Unfortunately, it's not so easy. Neither nozzle nor inlet efficiency are fixed values for a certain jet unit. The nozzle efficiency is depending on the operating point of the diffuser in front of it; if the diffuser is operating off its design point, there are strong secondary flows that effect the energy transfer in the nozzle. A nozzle of good design will have an efficiency in the range 95 to 98 %.

    The inlet efficiency is strongly dependent on inlet velocity ratios. For a fixed geometry, the inlet efficiency will vary with speed and with jet loading. So, in order to give an answer, particularly regarding the inlet you must provide more info on your setup.
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