On the motion of a solid sphere through a viscous medium with a vertical temperature gradient

In this payer, we report experiments conducted on the temperature distribut ion around a solid sphere that settles slowly in a thermally stratified vis cous fluid. The temperature field has been obtained using interferometry. I n some cases thermochromic liquid crystal tracers have been used to simulta neously obtain the velocity and the temperature fields. We also describe a theoretical analysis of the problem and compare experimental and theoretica l findings and discuss the results. we find that natural convection has a s ignificant influence in determining the nature of the temperature field awa y from the sphere.