Numerical Simulation on Mixed Convection in a Porous Medium Heated by a Vertical Cylinder

Numerical simulation has been performed for mixed convection of heated vertical cylinder with a constant temperature in a saturated porous medium subjected to lateral flow. Four different geometric aspect ratios 5,10,25 and 50 were considered, which give ratios of axial length to diameter. Based on dimensional analysis and nonlinear regression, correlations for the Nusselt number against the Rayleigh and the Peclet numbers have been obtained. It is shown that the average Nusselt number (Nu) is a function of the Rayleigh number (Ra d ) and the Peclet number ( Pe ): Nu=3.1√Pe for Ra d /Pe 1. As compared with Nu = 3.1√Pe for the case of horizontal forced flow around a vertical cylinder, the results of this investigation indicates that heat transfer can be remarkable enhanced by natural convection when forced convection is weak.