Abstract

A combined numerical approach featuring an immersed boundary and a cut cell method was implemented to discretize the conservation equations that model the discharge period of a solar energy accumulator based on phase change materials. The mathematical model consider three phases, i.e., the circulating fluid where a Low Reynolds model is used and the solid and liquid states of the phase change material for which a conjugate semi-implicit heat transfer scheme was implemented. Simulation results are compared with experimental data obtained from a laboratory scale solar accumulator containing paraffin wax as a phase change material finding good overall agreement.