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ISSN Online: 2377-424X

ISBN Print: 0-89116-559-2

International Heat Transfer Conference 8
August, 17-22, 1986, San Francisco, USA

NATURAL CONVECTION IN ENCLOSURES

Get access (open in a dialog) DOI: 10.1615/IHTC8.2330
pages 111-120

Abstract

Application of natural convection in enclosures stimulates the need for studies at high Rayleigh-numbers. Ventilation in rooms, passive and active solar systems and others have moreover mixed convective-radiative boundary conditions. Modern experimental techniques using laser optics can give more refined data to compare with numerical studies. However, in numerical studies seldom the full 3-D case with mixed b.c. has been solved. The effect of mixed boundary conditions on the onset of natural convective heat transfer will be discussed for narrow slot cavities. This is important for those cases where one wants to suppress convection. The use of partitions in the enclosure to reduce heat transfer at higher Ra-numbers has received considerable attention recently.
In natural convection at high Ra (109 - 1011) in enclosures with aspect ratio of about 1 the flow is typically of a boundary layer type. The b.l. flow will have an effect on the core stratification, which gives a coupling to both flow phenomena. Numerical simulation and experimental data on the use of a heated room with a cold window show complicated flow structures.