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Unpublished Paper
A Comparison of Turbulent Thermal Convection Between Conditions of Constant Temperature and Constant Flux
Physical Review Letters (2009)
  • Hans Johnston, University of Massachusetts - Amherst
  • Charles R. Doering
Abstract

We report the results of high-resolution direct numerical simulations of two-dimensional Rayleigh-Bénard convection for Rayleigh numbers up to Ra=1010 in order to study the influence of temperature boundary conditions on turbulent heat transport. Specifically, we considered the extreme cases of fixed heat flux (where the top and bottom boundaries are poor thermal conductors) and fixed temperature (perfectly conducting boundaries). Both cases display identical heat transport at high Rayleigh numbers fitting a power law Nu≈0.138×Ra0.285 with a scaling exponent indistinguishable from 2/7=0.2857… above Ra=107. The overall flow dynamics for both scenarios, in particular, the time averaged temperature profiles, are also indistinguishable at the highest Rayleigh numbers.

Disciplines
Publication Date
February, 2009
Comments
Prepublished version downloaded from ArXiv. Published version is located at http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.102.064501
Citation Information
Hans Johnston and Charles R. Doering. "A Comparison of Turbulent Thermal Convection Between Conditions of Constant Temperature and Constant Flux" Physical Review Letters (2009)
Available at: http://works.bepress.com/hans_johnston/2/