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Homework Help: Steam Table question

  1. Nov 1, 2005 #1
    Ok, using steam tables, calculate the specific entropy of steam with dryness fraction 0.63 and pressure of 2MPa.

    Can someone suggest how Id go about this?

  2. jcsd
  3. Nov 3, 2005 #2


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    Staff Emeritus
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    If it has a quality (dryness fraction), x = 0.63, it is saturated steam at 2 MPa.

    let y be a property, e.g. specific volume, v, specific enthalpy, h, specific internal energy, u, or specific entropy, s.

    In a two phase system, each phase has these properties,

    yf or yl , where f denotes fluid and l liquid


    yg or yv , where g denotes gas and v vapor.

    The property of the mixture is just the mass weighted sum of the liquid and vapor property.

    y = (1-x) yf + x yg, or

    y = yf + x yfg,

    where yfg = yg - yf
  4. Nov 3, 2005 #3
    Thanks Astronuc, I forgot that you could find entropy on the tables.
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