Abstract
Free convection velocity fields around the peripheries of horizontal tori in air have been measured for diameter ratios of 0.5, 0.3, and 0 (a cylinder) by utilizing the trajectories of fine zinc stearate particles. The induced flow through the torus opening and the curvature of the great circle were found to influence the velocity profiles and the location of the upper and lower stagnation points. Experimental profiles for tori are compared with theoretical results for cylinders and spheres proposed by others.