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A Connection between entropy and total pressure

  1. Sep 22, 2016 #1
    Hi guys,

    I'm struggling to understand why an increase of entropy is directly linked with a decrease of total (stagnation) pressure. I have an idea, but I'm not sure if this is right.

    My understanding of the problem is as follows:
    Shear stress (friction) is a part of the entropy production term of the entropy transport equation. So when looking at this transport equation the role of friction is clear to me.
    Furthermore shear stress is also contained in the source term of the kinetic energy and internal energy transport equation. Where friction converts kinetic energy into internal energy.
    Now when looking at Bernoulli's equation, total pressure is a combination of the static and the dynamic pressure. Dynamic pressure is related to kinetic energy.

    So could I say that friction simply reduces total pressure and increases entropy at the same time and there is actually no equation that describes a direct connection between these properties?

  2. jcsd
  3. Sep 22, 2016 #2
    From your understanding, what is the equation (or equations) for the rate of entropy generation per unit volume?
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