EXPERIMENTAL STUDY OF THERMAL CONVECTION WITH VOLUMETRIC ENERGY SOURCES IN A FLUID LAYER BOUNDED FROM BELOW BY A SEGMENT OF A SPHERE.

Steay state heat transfer coefficients are measured in a layer of dilute electrolyte bounded from below by a segment of a sphere maintained at zero heat flux and from above, by a horizontal surface at constant temperature; alternating current passing vertically through the fluid provides the volumetric energy source. It is found that the aspect ratio, the ratio of the maximum depth of the fluid to the characteristic horizontal dimension, has a significant effect on the Nusselt versus Rayleigh number relation at low values of this ratio. At high aspect ratios, the heat transfer correlation is nearly the same as that for a horizontal layer. Measurements of the temperature distribution on the lower boundary show that the maximum temperature occurs at the center and that large variations in temperature occur over a relatively restricted region near the edge.