Browsing by Author "Sheremet, Mikhail A."

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The effect of nano encapsulated phase change materials and nanoparticles on turbulent heat transport : a conical diffuser scenario
(Elsevier, 2022) Iachachene, Farida; Haddad, Zoubida; Arıcı, Müslüm; Abu-Nada, Eiyad; Sheremet, Mikhail A.
The present work investigates turbulent flow of single and hybrid nanofluids filled in a conical diffuser. The heat transfer coefficients and pressure losses are analyzed at various Reynolds numbers and nanoparticle volume fractions. The diffuser is filled with Al2O3, nano encapsulated phase change material NEPCM, and NEPCM_Al2O3 nanofluids. The thermophysical parameters of all nanofluids were determined using a novel methodology based on the thermodynamic equilibrium data for binary liquid mixtures. A notable novelty in the current work is the introduction of an innovative method of hybrid nanofluids composed of nanoparticles with and without phase change material (PCM). When compared to the other nanofluids tested, the NEPCM nanofluid presented the lowest pressure loss and the greatest heat transfer improvement within the diffuser. The Nusselt number of NEPCM nanofluids is enhanced by 15%, while for NEPCM_Al2O3 and Al2O3 nanofluids is increased by 10% and 6%, respectively. Similarly, the pressure drop is greater as compared to the base fluid, where the pressure drop is increased by 1%, 3.5%, and 5% for NEPCM, Al2O3, and NEPCM_Al2O3 nanofluid, respectively
Natural convection melting of phase change material in corrugated porous cavities
(Elsevier, 2022) Iachachene, Farida; Haddad, Zoubida; Abu-Nada, Eiyad; Sheremet, Mikhail A.
In this paper, a numerical study is carried out to examine the melting inside a wavy cavity under partial heating. A wide range of numerical computations have been performed to understand the effect of porosity, pore density, wall waviness, and heater location and intensity on the melting process. The results revealed that lower metal foam porosity resulted in higher melting rate and lower thermal storage capacity. However, pore density indicated no effect on melting performance for porosity in the range 80–96 %. When considering heater location at various porosities, its impact on melting performance is small at low porosity but becomes significant at higher porosity. Top–bottom partial heating can save almost 10 % of the melting time at ɛ = 0.96. Moreover, the PCM can store more energy, i. e. 11.36 %, when the heater location was changed from center or top–bottom position to top or bottom position at ɛ = 0.96. The results further showed that increasing the number of undulations can save 27.4 % of the melting time at ε = 0.96. Therefore, it can be concluded that higher energy storage and melting rate can be achieved by increasing the number of undulations
Numerical investigation and optimization of melting performance for thermal energy storage system partially filled with metal foam layer: New design configurations
(Elsevier, 2023) Haddad, Zoubida; Iachachene, Farida; Sheremet, Mikhail A.; ;Abu-Nada, Eiyad
Low thermal performance of storage systems represents a barrier to their industrial/engineering application and commercialization. Among all the proposed methods, combination of phase change material with metal foams appears more promising due to the high thermal conductivity of metal foams. However, the insertion of metal foams reduces the PCM volume; hence, a lower amount of stored energy. The present numerical study thoroughly addresses this issue with a focus on the optimization of melting performance for thermal energy storage system partially filled with metal foam layer. A finite volume method based on the enthalpy–porosity technique has been adopted for the numerical simulations. The metal foam location, porosity, and nanoparticle volume fraction were optimized to explore their effects on the melting performance. The results showed that inserting the foam layer diagonally from the top left to the right bottom leads to the lowest melting time. Compared to pure PCM, the melting time increases by 77.7%, while the stored energy decreases by 6.7%. The optimum porosity was found to be 0.88 as it gives approximately the same amount of stored energy as that of pure PCM with a deviation of 4%. Adding nanoparticles to pure PCM increases the melting rate by approximately 8%, while it decreases the stored energy by almost 3%. It is concluded that hybrid systems, i.e., metal foam at an optimum porosity and nanoparticles is more efficient than using each technique separately