A numerical inwestigation of thermal confection in a heat-generating fluid layer

A. A. Emara, F. A. Kulacki

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

Finite difference solutions of the equations governing thermal convection driven by uniform volumetric energy sources are presented for two-dimensional flows in a rectangular domain. The boundary conditions are a rigid, (i.e., zero slip), zero heat-flux lower surface, rigid adiabatic sides, and either a rigid or free (i.e., zero shear) isothermal upper surface. Computations are carried out for Prandtl numbers from 0.05 to 20 and Rayleigh numbers from 5 × 104 to 5 × 108. Nusselt numbers and average temperature profiles within the layer are in good agreement with experimental data for rigid-rigid boundaries. For rigidfree boundaries, Nusselt numbers are larger than in the former case. The structure of the flow and temperature fields in both cases is dominated by rolls, except at larger Rayleigh numbers where large-scale eddy transport occurs. Generally, low velocity upflows over broad regions of the layer are balanced by higher velocity downflows when the flow exhibits a cellular structure. The hydrodynamic constraint at the upper surface and the Prandtl number are found to influence only the detailed nature of flow and temperature fields. No truly steady velocity and temperature fields are found despite the fact that average Nusselt numbers reach steady values.

Original languageEnglish (US)
Pages (from-to)531-537
Number of pages7
JournalJournal of Heat Transfer
Volume102
Issue number3
DOIs
StatePublished - Jan 1 1980

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Nusselt number
Temperature distribution
temperature distribution
Prandtl number
Rayleigh number
heat
Fluids
fluids
Flow fields
flow distribution
two dimensional flow
energy sources
free convection
temperature profiles
low speed
Heat flux
heat flux
slip
Hydrodynamics
velocity distribution

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A numerical inwestigation of thermal confection in a heat-generating fluid layer. / Emara, A. A.; Kulacki, F. A.

In: Journal of Heat Transfer, Vol. 102, No. 3, 01.01.1980, p. 531-537.

Research output: Contribution to journalArticle

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