Publication Date:
2012-08-31
Description:
We present the results from numerical simulations of turbulent Rayleigh- Bé convection for an aspect ratio (diameter/height) of 1.0, Prandtl numbers of 0.4 and 0.7, and Rayleigh numbers from 1 × 105 to 1 × 109. Detailed measurements of the thermal and viscous boundary layer profiles are made and compared to experimental and theoretical (Prandtl-Blasius) results. We find that the thermal boundary layer profiles disagree by more than 10% when scaled with the similarity variable (boundary layer thickness) and likewise disagree with the Prandtl-Blasius results. In contrast, the viscous boundary profiles collapse well and do agree (within 10 %) with the Prandtl-Blasius profile, but with worsening agreement as the Rayleigh number increases. We have also investigated the scaling of the boundary layer thicknesses with Rayleigh number, and again compare to experiments and theory. We find that the scaling laws are very robust with respect to method of analysis and they mostly agree with the Grossmann-Lohse predictions coupled with laminar boundary layer theory within our numerical uncertainty. © 2012 Cambridge University Press.
Print ISSN:
0022-1120
Electronic ISSN:
1469-7645
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
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