Effect of location of a rotating circular cylinder and heat source on mixed convection heat transfer characteristics inside a square enclosure with discrete heater at the bottom wall

Abstract

A numerical investigation of mixed convection heat transfer phenomena in a square enclosure containing a heat conducting rotating circular cylinder has been taken into consideration in this work. As a heat source, a discrete isoflux heater is placed at the bottom wall of the enclosure whereas the top wall is considered as adiabatic. The vertical sidewalls of the enclosure are assumed to be maintained at constant low temperature to properly describe the boundary conditions in the work. The coupled equations of the developed mathematical model are solved by using the finite element method based on the Galerkin method of weighted residuals for different rotating speeds of the cylinder varying over the range of 0-500 keeping the Rayleigh number and Prandtl number fixed. The effects of position of rotating cylinder (both horizontal and vertical) and location of the heat source on the streamlines, isotherms, variation of local Nusselt number, average Nusselt number and other heat transfer and fluid flow phenomena are numerically investigated. The results reveal that the flow field, temperature field and heat transfer rate strongly depend on cylinder and heat source position.