Computational assessment of cold thermal energy storage improvement using hybrid nanofluid cooling and metal foam media.

This article conducts an in-depth numerical investigation of an advanced cold thermal energy storage system based on an annular enclosure incorporating dual cold boundaries and radial fin elements to promote faster solidification. The system performance is improved through the combined application of several heat transfer enhancement techniques, namely porous metallic foam, hybrid nanoparticle-based working fluids, and the inclusion of radiative heat transfer effects. The porous foam matrix enhances overall thermal conduction by facilitating efficient heat transport across the storage region, whereas the hybrid nanomaterials intensify heat transfer at the microscale. The formulated mathematical model captures transient phase-change behavior while simultaneously accounting for conductive and radiative heat transfer mechanisms. A Galerkin finite element approach with an implicit time-stepping scheme and adaptive mesh refinement is adopted to precisely track the moving solid-liquid interface. Validation against established results from the literature demonstrates strong agreement. The results indicate that incorporating thermal radiation reduces the freezing time by approximately 22.95%, underscoring its importance in low-temperature energy storage applications. The most pronounced enhancement is achieved through porous foam implementation, which decreases the solidification duration by nearly 79.19%, while replacing water with a hybrid nanofluid provides an additional reduction of about 5.81%.