Radiative Entropy Generation: interactions with other phenomena

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Radiative Entropy Generation interactions with
other phenomena
IRREVERSIBLE THERMODYNAMICS COURSE LABORATORY OF
APPLIED THERMODYNAMICS, HELSINKI UNIVERSITY OF
TECHNOLOGY, FINLAND

• Miguel Gama Caldas, PhD
• miguelcaldas_at_mail.telepac.pt
• 2nd November 2006

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Outline of the lecture

• Global balance equations for a control volume
  radiation matter
• Entropy generation in a general reacting and
  radiating flow
• Effect of turbulence-radiation interaction (TRI)
  on entropy generation

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Balance equation for a control volume
A general balance equation for a control volume
can be written as
If we whish to separate contributions from the
material and radiative fields, we will get
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Balance equation for a control volume (cont)
Formulating the material contribution in terms of
specific mass
We get, after expansion
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Balance equation for a control volume (cont)
Recalling the continuity equation
We get
or
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Momentum balance equation
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Momentum balance equation (cont)
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Momentum balance equation (cont)
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Total energy equation
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Mechanical energy equation
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Internal energy equation
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Internal energy equation (cont)
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Entalpy equation
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Entropy equation
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Entropy equation (cont)
A lot of calculations
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Entropy equation (cont)
Newtonian fluid
Mixture of perfect gases
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Radiative term of the entropy equation
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Interaction with Turbulence
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Turbulence-Radiation Interaction (TRI)
Reynolds decomposition
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Averaging of the energy source term
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Averaging of the ETCR
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Approximated averaging
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Averaging of the entropy source term
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Averaging of the entropy source term (cont)
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Averaging of the entropy source term (cont)
?
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Averaging procedure
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Averaging procedure (cont)
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Averaging procedure (cont)
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Equation of transport of turbulent fluctuations
of radiative intensity
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Eq of transp of turb fluct of radiative intensity
(cont)
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Equation of transport of turbulent fluctuations
of radiative intensity
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Case study
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Q total - (sT/T)ch0
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SG total (sT/T)ch0
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Q total (sT/T)ch0.25
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SG total (sT/T)ch0.25
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Resultados IRT transferência de calor e geração
de entropia
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TRI material can also be found in

• Caldas, M. and Semião, V. (2007), The Effect of
  Turbulence-Radiation Interaction on Radiative
  Entropy Generation and Heat Transfer, Journal of
  Quantitative Spectroscopy and Radiative Transfer,
  in press, available on-line since 15 September
  2006.