Thermal energy storage (TES) will be a key feature in the evolving energy landscape. However,

conventional storage tanks, using sensible heat, have a low energy density. Phase change

materials (PCM), using latent heat, can achieve far higher energy densities. PCM thermal

conductivity is low however. Therefore it is difficult to achieve high power densities. 3D finned

structures, such as metal foam can increase the heat transfer rate. Metal foam is a 3D finned

structure possible of reducing the melting time by a factor of four. To design metal foam enhanced

PCM, a general thermohydraulic model is needed. The thermohydraulic behavior of metal foam

enhanced PCM can be modeled using a volume averaged (VAT) model. Present VAT models do not

have PCM dedicated closure terms. Furthermore, they neglect the effect of state of the PCM

(solid-mushy-liquid) on the interstitial heat transfer. In this project, a novel experiment is

developed to fill in this gap by measuring the interstitial heat transfer coefficient with respect to

phase state. The experiments are supplemented by pore scale simulations of phase change in

foam structures to get further insight into the fundamental driving forces of the heat transfer

process. The result will be a general thermodraulic model for metal foam enhanced PCM. The

model will be used to evaluate general reference geometries. The novel experiment and method

can furthermore serve as a blueprint for modeling phase change in other 3D finned structures.