Laminar mixed convection heat and mass transfer in horizontal circular tube with uniform heat and mass fluxes at the walls on part of its length have been investigated numerically using a three - dimensional elliptic equations model. The effect of the Schmidt number and the buoyancy ratio N, on the development of the hydrodynamic, thermal and solutal fields and the axial evolution of the Nusselt and the Sherwood numbers are presented. These results showed that the Schmidt number has the highest effect on the flow rather than the Nusselt and Sherwood numbers. The Nusselt number and Sherwood number increase for positive N and decrease when N is negative.
heat transfer, mass transfer, mixed convection, schmidt number, horizontal tube (3D), elliptic equations
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