Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 0-89116-559-2

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

EVALUATION OF NATURAL AND FORCED-CONVECTION HEAT TRANSFER COEFFICIENTS IN AND OVER AN ENCLOSURE BY MACH-ZEHNDER INTERFEROMETRY

Get access (open in a dialog) DOI: 10.1615/IHTC8.2600
pages 513-518

Abstrakt

A Mach-Zehnder interferometer was combined with a low-speed wind tunnel to study the temperature fields over a simulated absorber plate and the glazing of a model of a flat plate solar collector. The model and the apparatus provided accurate and consistent interferograms within the cavity over the absorber plate and over the glazing. The temperature fields were determined from the interferograms, which in turn yielded the local Nusselt numbers for the natural convection in the cavity and the forced convection on the glazing cover.
As the result of this investigation, critical Rayleigh number of 1717, two equations are recommended for the Nusselt numbers for the natural convection heat transfer in the horizontal cavity and the forced convection over the glazing. These equations are compared with those recommended by other investigators for similar conditions.