A numerical and experimental study was performed to analyze the influence of natural convection on heat transfer in a composite system comprising a porous material heated from below and an air space above. The numerical model was verified by conducting a number of experiments on a model material consisting of polystyrene pellets of cylindrical shape with hemispherical ends, made in the Wind Box. This apparatus, a guarded hot plate of large measuring area, is a prototype. In designing the measuring process, calculation of the maximum systematic error has been a control parameter; this is less than 6%. The study included measurements in the Wind Box and calculations with a computer simulation program (CONVBOX) for three-dimensional convection problems. The agreement between the calculations and the experimental results is, in general, good.

AUTHOR: Mihail G. Serkitjis, Ph.D.
CITATION: Thermal Performance of the Exterior Envelopes of Buildings VII
KEYWORDS: December, Florida, 1998
YEAR: 1998