MODELING OF CONVECTIVE HEAT-TRANSFER ON T HE VERTICAL WALLS OF CAVITIES AT HIGH RAYLEIGH NUMBERS

Modelling of convective heat transfer on the vertical walls of cavitie s at high Rayleigh numbers. The objective of this experimental study i s to determine the convective heat transfer on the vertical walls of t wo large cavities with different aspect ratios (Rayleigh numbers varyi ng from 10(9) to 10(11)) when the flows ave due to a temperature diffe rence between opposite vertical walls. We show that the characteristic temperature to define the overall heat transfer on each surface shoul d include the bulk temperature. The results obtained indicate that thi s temperature can be calculated with accuracy by determining the avera ge of the six wall temperatures. The Nusselt numbers on the four verti cal walls defined by this reference temperature collapse to a single c orrelation when different configurations of differentially heated and cooled vertical walls ave applied.