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In this study, experiments are conducted to measure the thermal resistances of heat sinks with cross-cut branched fins on horizontal cylinders. The experiments were conducted for several numbers of fin, heights of fins, and heat inputs. From the experimental data, the Nusselt number correlation for Rayleigh numbers of 190000–1000000, fin heights of 10–30 mm, and fin numbers of 9–36 is proposed. Using the suggested correlation, the fin thickness and fin number for maximizing the thermal performance are obtained. Finally, it is demonstrated that the optimal heat sink with cross-cut branched fins on a horizontal cylinder has 26 % lower thermal resistance than that of a conventional heat sink with plate fins. [ABSTRACT FROM AUTHOR]

Using phase change materials (PCMs) in energy storage systems provides various advantages such as energy storage at a nearly constant temperature and higher energy density. In this study, we aimed to conduct a numerical simulation for augmenting a PCM’s melting performance within multiple tubes, including branched fins. The suspension contained Al2O3/n-octadecane paraffin, and four cases were considered based on a number of heated fins. A numerical algorithm based on the finite element method (FEM) was applied to solve the dimensionless governing system. The average liquid fraction was computed over the considered flow area. The key parameters are the time parameter (100 ≤t≤600 s) and the nanoparticles’ volume fraction (0%≤φ≤8%). The major outcomes revealed that the flow structures, the irreversibility of the system, and the melting process can be controlled by increasing/decreasing number of the heated fins. Additionally, case four, in which eight heated fins were considered, produced the largest average liquid fraction values.

Using phase change materials (PCMs) in energy storage systems provides various advantages such as energy storage at a nearly constant temperature and higher energy density. In this study, we aimed to conduct a numerical simulation for augmenting a PCM's melting performance within multiple tubes, including branched fins. The suspension contained Al2O3/n-octadecane paraffin, and four cases were considered based on a number of heated fins. A numerical algorithm based on the finite element method (FEM) was applied to solve the dimensionless governing system. The average liquid fraction was computed over the considered flow area. The key parameters are the time parameter ( 100   ≤ t ≤ 600   s) and the nanoparticles' volume fraction ( 0 % ≤ φ ≤ 8 %) . The major outcomes revealed that the flow structures, the irreversibility of the system, and the melting process can be controlled by increasing/decreasing number of the heated fins. Additionally, case four, in which eight heated fins were considered, produced the largest average liquid fraction values. [ABSTRACT FROM AUTHOR]