Investigating the thermal performance of nano-encapsulated phase change materials-water nanofluid in the presence of a heat source as applied in electronic devices

Background: Global warming and the human need for power resources in the last decades have highlighted the concerns related to energy saving for long-term applications. Thermal energy-saving systems are an important technique to overcome this issue.Methods: In the present study, we aim to simulate the performance of a thermal energy-storing system with NanoEncapsulated Phase Change Materials (NEPCMs) by Computational Fluid Dynamics (CFD). Free convection heat transfer through a square enclosure is numerically simulated, and a hot block is located at pisitions of the enclosure. The simulation is done with the FVM method and SIMPLE algorithm. The analyzed parameters are different Ra numbers (5 x 103 - 105), non-dimensional melting temperatures (0.1 < & theta;f < 0.9), and NEPCM melting intensities (0.01 < & chi; < 0.03).Significant Findings: T The results revealed that the & theta;f = 0.3 is corresponding to the optimum heat transfer rate, and it is independent of the Ra number. In the case with the highest heat transfer rate, adding NEPCMs to the based fluid caused the heat transfer to improve by 12.5%. Furthermore, in this & theta;f number, uniform heat transfers through the cold walls of the enclosure. A low number of & chi; also revealed less Nusselt number. Increasing AR in high Ra number improves Nusselt number by 5%.