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Water-air composite pressure system

  1. Jun 5, 2012 #1
    Hi all,
    This is my first post since I'm unable to find the answer myself & on the net too.
    My query is lets consider we have 3 types of system

    1. Air tank at 10 bar pressure.
    It will have105*10*1= 1000 KJ energy.

    2. Water tank of volume 1 cum and height of 1 m.
    It will have 5.04*h2 = 5.04 KJ (h= water head pressure)

    3. Now lets say we have 2 cum of volume containing water of 1 cum and 1 cum air at 10 bar.
    can I say we have energy in water= 5.01*1002 = 50400 KJ (10 bar=100 m of water)
    plus when water is out of tank volume of air will be 2 cum at 5 bar.
    then energy stored in air (considering isothermal expansion)= 500 KJ
    so total 50900 KJ.

    Am I doing wrong some where/ everywhere then where is it wrong?
    If not why there is so diffrence in energy?
  2. jcsd
  3. Jun 6, 2012 #2
    calling all scholars
  4. Jun 8, 2012 #3
    Pls help.
    Don't any one here study hydraulics.
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