Numerical study of the unsteady mixed convection heat transfer from a circular cylinder

Abstract

The strictly-periodic mixed convection heat transfer from a circular cylinder has been numerically investigated at the two Reynolds numbers, 100 and 200, in the Richardson number range 0≤ Ri≤1 . It is found that an excessive heating of the cylinder (that is, for the Richardson number larger than a critical value) causes a singular decay of the dynamic vortices to the stationary twin vortices attached to the cylinder, and ultimately to a vortex-free symmetric flow past a circular cylinder. The over-all Nusselt number is found sensitive to this change of the flow patterns.