Numerical Study of a Non-Newtonian Phase Change Flow in Finned Rectangular Enclosures

Phase change materials (PCMs) are widely used for thermal energy storage systems due to their effective thermal properties for energy accumulation. Simultaneously, this material has poor thermal conductivity, and for the optimization of such systems, many techniques are used. This study focuses on an analysis of PCMs in a vertical cavity with one, two, or three solid fins and differential heating. The finite element procedure has solved governing equations formulated using the power-law approach for the non-Newtonian PCM and enthalpy-porosity method. The developed code has been verified using numerical and experimental data from other authors. Effects of fins number and power-law index on flow and thermal structures within the cavity have been studied. It has been found that a rise in the power-law index illustrates a growth of time for the charging level of the storage system, while the addition of a solid fin from one to three allows for reducing the charging time. The extended heat transfer surface can be applied to optimize the thermal energy storage system.