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ISSN Online: 2377-424X

ISBN CD: 1-56700-226-9

ISBN Online: 1-56700-225-0

International Heat Transfer Conference 13
August, 13-18, 2006, Sydney, Australia

EXPERIMENTAL AND NUMERICAL STUDY OF NATURAL CONVECTION AROUND A SQUARE DISK

Get access (open in a dialog) DOI: 10.1615/IHTC13.p6.170
11 pages

Résumé

This paper is based on a previous study of the authors in which natural convection around a square disk was studied experimentally. In this paper Ra is varied by changing the acceleration in a cavity. The acceleration in the cavity was varied from 9.81 m/s2 to 53 m/s2 by using a centrifuge. This way, Ra is varied in the range 105 < RaA < 106 or 6·104 < RaL < 3·105, depending on the characteristic length to define Ra. This is an interesting range of Ra because the values lie in a transitional zone between laminar thin boundary layer dominated and conduction dominated natural convection. The experimental data is compared with existing correlations to check if these correlations are valid and accurate enough in this intermediate range of Ra.
The experimental research is now numerically simulated, in order to visualize the flow inside the cylinder and to extend the number of data points. The numerical simulations are first verified by the experimental results. After verification, the numerical simulations were used to extend the research to lower Ra-values in the transitional range. This can not be done experimentally with the available setup. It is checked whether the experimentally obtained correlation for Ra can be extended for lower Ra-numbers. The influence of the size of the cylindrical container was also studied numerically. It was concluded that the initial size of the cylinder was not big enough to avoid any influence of the cavity on flow. However, this does not influence the Ra-Nu correlation very much.