In this paper, a numerical model is established to predict the phase change material (PCM) melting process in porous media. The heat transfer enhancement technique using metal foam in a shell-and-tube type latent heat thermal energy storage (LHTES) unit is investigated. The solid-liquid phase change phenomenon is solved with the enthalpy porosity theory. The computational fluid dynamic technology is adopted to predict the flow and heat transfer for the liquid PCM and heat transfer fluid (HTF). The appropriate source terms accounting for the pressure drop caused by the presence of solid PCM and porous media are added to the momentum equations. The solid-liquid interface position and the temperature distribution are predicted to describe the melting process. The effects of the structural parameters of porous media and the inlet conditions of HTF on the thermal characteristics of LHTES unit are analyzed. The numerical model can be further extended to investigate the thermal performance of different types of storage units in LHTES system. (C) 2013 Elsevier Ltd. All rights reserved.