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• Thermal behavior of rectangular fins located within a square cavity were analyzed. • Inverse CFD method and experimental data were adopted for heat transfer prediction. • Suitable turbulence model based on the RMSE of the flow model were selected. • Effect of fin geometry on the flow and heat transfer within a cavity was evaluated. • Effect of PCM heat sink on the flow and heat transfer within a cavity was studied. This study examines the fluid flow and heat transfer characteristics of rectangular fins positioned within a square cavity through the use of the inverse three-dimensional computational fluid dynamics (CFD) method, experimental analysis, and the constant heat transfer rate assumption. This paper proposes a heat sink that uses a phase change material (PCM) made of paraffin within a small cavity. The inverse CFD method, combined with the least squares method, root mean square error, and excessive experimental data, is adopted to predict the unknown heat transfer rate Q and absorption heat Q ab. One of the objectives of this study is to investigate the effect of the PCM heat sink on fluid flow and heat transfer characteristics within a cavity. A sequence of tests on various flow models indicates that employing the RNG k-ε turbulence model with the standard wall function is the most suitable choice for all scenarios in the three-fin model. Conversely, the zero-equation model proved to be a more adequate fit for the PCM heat sink. Another objective of this study is to study the effect of the height of the PCM heat sink on Q and Q ab. The incorporation of a PCM heat sink results in a further improvement in the efficiency of heat dissipation. Part of the heat created is absorbed by the PCM heat sink, which absorbs 22.5 % of the thermal energy. Under the same volume, the PCM heat sink with a lower height (H p = 0.012 m) absorbs 14 % more heat compared to H p = 0.02 m. Thus, a lower-height PCM heat sink has a better heat dissipation effect. [ABSTRACT FROM AUTHOR]

This research aims to present the preparation, characterization and thermophysical properties of water-based microencapsulated n -eicosane PCM suspensions for thermal energy storage. n- eicosane PCMs are coated with urea–formaldehyde polymer shell. The microcapsules have been characterized by Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses. The differential scanning calorimetry (DSC) is also performed for measurement of the latent heat value, melting and freezing temperatures, and specific heat of MEPCMs. Then, the thermophysical characteristics of the MEPCM suspension including the thermal conductivity k m and viscosity µ m have been measured at different particle concentration (2, 5 and 10 wt%) and different temperatures from 25 to 50 °C. New correlations are developed to predict the thermophysical characteristics of MEPCM suspensions. Furthermore, the application performance of artificial neural network for predicting of k m and µ m is evaluated, and it is found that a neural network with the optimum structure of 2-4-4-2 provides a very accurate prediction of the experimental results. [ABSTRACT FROM AUTHOR]

This research study investigated the cooling performance of a minichannel heat sink that employed suspensions of microencapsulated phase change material (MEPCM) particles as the working fluid. The heat sink made from copper consisted of 10 rectangular minichannels, with a length of 50 mm, depth of 1.5 mm and a width of 1 mm. A uniform heat flux was used for heating the mini channel heat sink and the Reynolds numbers were in the range of 133–1515. The concentration of the MEPCM particles scattered in the water varied from 0 to 10 wt%. The experimental data showed that the wall temperature highly relied upon the Reynolds number and the increment of Reynolds number lead to the reduction of wall temperature for the coolant with or without MEPCM suspension in the minichannel heat sink. Moreover, the wall temperature got reduced for a coolant with MEPCM, compared to that without MEPCM especially at lower Reynolds numbers. Interestingly, the measured results revealed that the coolant with MEPCM particles was effective in cost performance than the pure coolant. The best cooling performance compared to that of pure water was observed for 2% MEPCM concentration within the considered range of flow rates. [ABSTRACT FROM AUTHOR]