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Decrease in Entropy

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Old   August 30, 2007, 00:52
Default Decrease in Entropy
  #1
RAMU MADDI
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I am solving Axial turbine blade through cfx. I am using material as steam. When I am checking the static entropy at inlet and exit, i found the inlet entropy is more than the exit entropy which is against physics.Can any one help me in this issue, what could be the problem.
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Old   September 3, 2007, 08:51
Default Re: Decrease in Entropy
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Dr. V. Kumar
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It is not against physics. Since you have inlet/outlet it is an open system and thermodynamics says that entropy of an isolated system can not decrease.

What is happening in between inlet and outlet will be an indicator that why entropy is decrease/increased e.g. heat loss or friction etc.

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Old   September 4, 2007, 09:55
Default Re: Decrease in Entropy
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CycLone
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This is exactly what you should expect from a steam turbine. Just look as the H-S diagram for the cycle.

-CycLone
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Old   September 4, 2007, 10:09
Default Re: Decrease in Entropy
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CycLone
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...I should add that the entropy of the stage should increase, but it is expected to see a drop in entropy through the rotor.

-CycLone
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