Numerical investigation of a thermal energy storage with phase change material under periodic boundary conditions

This paper investigates the behavior of a Thermal Energy Storage (TES) under periodic boundary conditions. An analytical model is adapted to the studied case and solved for a 2D configuration using a commercial computational fluid dynamics (CFD) software. It permits to find the temperatures and the velocities in the medium and to track the solid/liquid interface and to study the response of the system to any given excitation. The results are validated for the complex case of water seen as PCM in the convenient temperature range. Results show that the input temperature amplitude is hugely damped at the opposite side level and the phase is shifted. The equivalent diffusive medium simplified approach is considered and its limitations are pointed out.