NUMERICAL SIMULATION OF NATURAL CONVECTION HEAT TRANSFER IN A TRANSFER PIPE FOR A COAL OIL MIXTURE.

A numerical analysis is presented for natural convection heat transfer in a transfer pipe of a Coal Oil Mixture left bracket COM right bracket using a finite element method. A non-Newtonian fluid model is adopted to describe the flow behavior of the COM considering variable viscosity effect with temperature. The flow velocity and temperature distributions in the pipe are different in the case of heating and cooling due to the strong effect of the variable viscosity of the fluid. The effect of the variation of Rayleigh Number on heat transfer is examined for some cases of non-Newtonian fluids. Nusselt numbers at the pipe wall are also given for the heating and cooling cases.