External Natural Convection

  • Donald A. Nield
  • Adrian Bejan


Numerical calculation from the full differential equations for convection in an unbounded region is expensive, and hence approximate solutions are important. For small values of the Rayleigh number Ra, perturbation methods are appropriate. At large values of Ra thermal boundary layers are formed, and boundary layer theory is the obvious method of investigation. This approach forms the subject of much of this chapter. We follow, to a large extent, the discussion by Cheng (1985a).


Boundary Layer Heat Flux Porous Medium Nusselt Number Natural Convection 
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Copyright information

© Springer Science+Business Media New York 1999

Authors and Affiliations

  • Donald A. Nield
    • 1
  • Adrian Bejan
    • 2
  1. 1.Department of Engineering ScienceUniversity of AucklandAucklandNew Zealand
  2. 2.Department of Mechanical Engineering and Materials ScienceDuke UniversityDurhamUSA

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