Heat transfer performance assessment for forced convection in a tube partially filled with a porous medium

Heat transfer performance assessment was made for forced convection in a heated tube with a porous medium core and a tube with a wall covered with a porous medium layer, so as to investigate effectiveness of porous material insertion within a tube. Both local thermal and non-thermal equilibrium analyses were carried out for the two cases of partial porous medium filling, to investigate the validity of local thermal equilibrium assumption. It has been found that the local thermal non-equilibrium analysis is essential for the case of forced convection in a tube with a heated wall surface covered with a porous medium layer, whereas the local thermal equilibrium analysis suffices to capture transport phenomena for the case of forced convection in a tube with a porous medium core. In a comparatively low range of pumping power, the heat transfer performance of the tube with a porous medium core is higher than that of the tube with a wall covered with a porous medium layer. However, in a high range of pumping power, the latter performance exceeds the former.

► Both LTE and LTNE analyses were carried out in this study. ► The LTNE analysis is essential for the case of a porous medium layer on the wall. ► However, the LTE analysis is effective for the case of a porous medium in the core region. ► The heat transfer performance assessment was investigated under equal pumping power. ► The appropriate placement of porous media varies with the range of pumping power.