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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

A NEW NUSSELT/RAYLEIGH NUMBER CORRELATION AND WALL FUNCTIONS FOR TURBULENT RAYLEIGH-BÉNARD CONVECTION

Get access (open in a dialog) DOI: 10.1615/IHTC13.p6.10
11 pages

要約

The temperature profile of turbulent Rayleigh-Bénard convection is analysed asymptotically. It is found that it consists of a wall layer and a fully turbulent core layer, with an overlap layer in between. By asymptotic matching of temperature gradients of the wall layer and the core layer, a universal temperature profile is obtained. It is a logarithmic function of the wall distance and valid in the overlap layer. It is further assumed that the profile is valid up to the center line of the cell, as indicated by various studies. The temperature profile then can be transformed into a Nusselt/Rayleigh correlation that is in good agreement with recent experimental and numerical data. Furthermore, the temperature profile can be used as a temperature wall function in CFD codes to simulate Rayleigh-Bénard convection or similar flows. Here, it is implemented in a two dimensional CFD code and results are compared to measured profiles in a cell of aspect ratio one.