Numerical study of heat transfer enhancement for a novel flat-plate solar water collector using metal-foam blocks

This paper reports a numerical study of enhanced forced convection in a channel of solar water collector using multiple metal-foam blocks. Both Darcy–Brinkman–Forchheimer flow model and two-equation energy model based on local thermal non-equilibrium are used to characterize the thermo-flow fields inside the porous regions. Solution of the coupled governing equations for the porous/fluid composite system is obtained using a stream function-vorticity analysis. The results show that the recirculation caused by metal-foam block will significantly augment the heat transfer rate on heated surface. Besides, a useful correlated equation to predict Num is proposed and the validity of the LTE condition is examined.