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Transport in Porous Media

, 80:399 | Cite as

Further Comments on “Combined Forced and Free Convective Flow in a Vertical Porous Channel: The Effects of Viscous Dissipation and Pressure Work”

  • E. MagyariEmail author
Article

Abstract

This note is concerned with the assertion of Barletta and Nield (2009a) that “a fluid with a thermal expansion coefficient greater than that of a perfect gas (ββ perfect gas) is of marginal or no interest in the framework of convection in porous media”, and that for a remark of Magyari (Transp. Porous Media, 2009) about the forced convection eigenflow solutions, the circumstance ββ perfect gas does not represent “a sound physical basis”. Here, it is shown, however, that these assertions are in contradiction with the experimentally measured values of β for important technical fluids as e.g., air, nitrogen, carbon dioxide, and ammonia where, in the temperature range between −20 and +100°C, just the inequality ββ perfect gas holds.

Keywords

Mixed convection Laminar flow Porous media Viscous dissipation Pressure work Analytical solution 

References

  1. Baehr H.D., Stephan K. (1994) Wärme- und Stoffübertragung. Springer, BerlinGoogle Scholar
  2. Barletta, A., Nield, D.A.: Response to comment on “Combined forced and free convective flow in a vertical porous channel: the effects of viscous dissipation and pressure work”. Transp. Porous Media (2009a). doi: 10.1007/s11242-009-9365-6
  3. Barletta, A., Nield, D.A.: Combined forced and free convective flow in a vertical porous channel: the effects of viscous dissipation and pressure work. Transp. Porous Media (2009b). doi: 10.1007/s11242-008-9320-y
  4. Magyari, E.: Comment on “Combined forced and free convective flow in a vertical porous channel: the effects of viscous dissipation and pressure work”. Transp. Porous Media (2009). doi: 10.1007/s11242-009-9366-5

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  1. 1.Institut für Hochbautechnik, ETH ZürichZürichSwitzerland

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