Metal Foam Layer Research Articles

A 3D Model of a Photovoltaic Thermal Panel with the Heat Transfer Fluid Tube Embedded in a Layer of Phase Change Material and Metal Foam

A 3D Model of a Photovoltaic Thermal Panel with the Heat Transfer Fluid Tube Embedded in a Layer of Phase Change Material and Metal Foam

A shell-tube latent heat thermal energy storage: Influence of metal foam inserts in both shell and tube sides

Enhancing heat transfer in latent heat thermal energy storage systems is of utmost importance to facilitate the efficient absorption and release of thermal energy. The primary objective of the current study is to investigate the influence of a metal foam layer on heat transfer enhancement in both the heat transfer fluid side and the shell side. The research explores the incorporation of a fixed 30 % foam layer, which can either extend along the tube wall or penetrate deeper into the shell, moving away from the heat transfer fluid tube. A local thermal non-equilibrium two-temperature heat equation model is utilized to mathematically model the interactions within the metal foam embedded in the heat transfer fluid tube and the phase change material domain. The governing equations are solved using the finite element method. The results indicate that adjustments to the inlet pressure and the metal foam shape parameter (FL) can significantly reduce the melting time, with a variation of approximately 40 %. Specifically, at a constant inlet pressure of 750 Pa, the energy storage power at a 90 % charging increases from 32.2 W (FL = 0.75) to 48.7 W (FL = 1.37). A modification of FL shape parameter increased the power output by 34 %.

Improvement of Latent Heat Thermal Energy Storage Rate for Domestic Solar Water Heater Systems Using Anisotropic Layers of Metal Foam

Latent Heat Transfer Thermal Energy Storage (LHTES) units are crucial in managing the variability of solar energy in solar thermal storage systems. This study explores the effectiveness of strategically placing layers of anisotropic and uniform metal foam (MF) within an LHTES to optimize the melting times of phase-change materials (PCMs) in three different setups. Using the enthalpy–porosity approach and finite element method simulations for fluid dynamics in MF, this research evaluates the impact of the metal foam’s anisotropy parameter (Kn) and orientation angle (ω) on thermal performance. The results indicate that the configuration placing the anisotropic MF layer to channel heat towards the lower right corner shortens the phase transition time by 2.72% compared to other setups. Conversely, the middle setup experiences extended melting periods, particularly when ω is at 90°—an increase in Kn from 0.1 to 0.2 cuts the melting time by 4.14%, although it remains the least efficient option. The findings highlight the critical influence of MF anisotropy and the pivotal role of ω = 45°. Angles greater than this significantly increase the liquefaction time, especially at higher Kn values, due to altered thermal conductivity directions. Furthermore, the tactical placement of the anisotropic MF layer significantly boosts thermal efficiency, as evidenced by a 13.12% reduction in the PCM liquefaction time, most notably in configurations with a lower angle orientation.

Three-dimensional simulation of a proton exchange membrane fuel cell with non-integrated metal foam as flow distributor

In proton exchange membrane fuel cells (PEMFCs), the presence of metal foam in the flow channels improves the polarity diagram and increases the cell generated power, but this leads to an increase in pressure drop and, as a result, an increase in parasitic power. In this study, two types of non-integrated arrangements of metal foam are introduced, which, in addition to having high generated power, have lower pressure drop, and subsequently, lower parasitic power, and will also result in a more uniform distribution of temperature and current density. In the first arrangement, which is called IPTG, an abbreviation of Increased Porosity Toward the gas diffusion layer (GDL), the channels are divided into four equal parts with variable porosities from 0.65 to 0.95, in such a way that the metal foam layer with the highest porosity (0.95) is located in the closest area to the GDL. In the second arrangement which is called Reduced Porosity Toward the GDL, the metal foam layer with the least porosity (0.65) is located in the closest area to the GDL. To make a better comparison between the present model and the conventional one, the net power parameter with subtracting parasitic power from generated electrical power of the fuel cell is calculated for all models. The numerical study of this paper is conducted by developing a three-dimensional computational fluid dynamics model by employing user-defined functions. The results show that the net power of the PEMFC with IPTG arrangement is 3.8 % higher than that of the one with integrated metal foam arrangement with a porosity of 0.95. Also, the higher the pores per inch (PPI) of metal foam used in the non-integrated metal foam model, the greater the net power of the fuel cell, so that, the net power of PEMFC with IPTG arrangement with PPI=80 is 3.2 % more than that of PPI=20.

Improving phase change heat transfer in an enclosure partially filled by uniform and anisotropic metal foam layers

Anisotropic metal foams exhibit exceptional potential for improving the efficiency of latent heat thermal energy storage (LHTES) units by enhancing heat transfer and thermal energy storage rates. This study explores the largely uncharted area of thermal behavior of anisotropic metal foams in varied configurations and enclosure designs. The research focuses on an LHTES unit with a specific channel configuration, constructed using copper and containing three layers of copper metal foam, one of which is anisotropic and infused with paraffin wax. The finite element method was utilized to manage the complexities emerging from phase change, and the anisotropic angle varied from 0 to 90° in three different placements of the AMFL: top, middle, or bottom of the enclosure. The ideal design was achieved with an AMFL in the middle with a 0°angle, resulting in a 3.7 % reduction in melting time and approximately a 2.3 % reduction in solidification time. However, AMFL designs at the middle placement with a 75° anisotropic angle were less effective, hampering the melting and solidification processes, thus potentially extending charging and discharging times. The study concludes that the placement and angle of the AMFL layer are vital for the heat transfer capabilities of phase change materials. AMFL at the middle with a 0° angle optimally leverages temperature gradients, enhancing heat transfer compared to other investigated cases. An AMFL in the middle with a 0° angle exhibits approximately 7.1 % and 6.3 % improvements for melting fractions of 0.9 and 0.95, respectively, underscoring its potential for efficient thermal energy storage.

Optimizing of a metal foam-assisted solar air heater performance: a thermo-hydraulic analysis of porous insert placement.

A numerical assessment of the heat transfer efficacy of a solar air heater (SAH) was carried out. The SAH is supplied with a porous metal foam layer to improve thermal mixing. Both the local thermal non-equilibrium (LTNE) and Darcy-extended Forchheimer (DEF) models were employed to forecast fluid and thermal transport within the partly filled SAH channel. The analysis was performed for various values of dimensionless foam layer lengths ( ), pore densities ( ), and Reynolds numbers ( ) at a fixed value of layer thickness ( ). Based on the position of the porous layer, three distinct arrangements, marked as Case 1, Case 2, and Case 3, were explored. Regarding the parameters examined, the findings indicate a definite improvement in the average Nusselt number ( ), but unfortunately, the friction factor also increases unfavorably. By reducing the length of the porous layer, a reasonable reduction in heat transfer rate and a significant decrease in pressure drop were noticed. The results showed about 26.64%, 48.73%, and 70.74% reductions in pressure drop by reducing the dimensionless foam length from 1 to 0.25, 0.5, and 0.75 respectively for at . On the other side, there are only about 11.05%, 23.11%, and 40.78% reductions in . The exhaustive analysis of the thermal performance of SAH was conducted using the thermal performance factor (TPF), which considers the trade-off between the SAH channel's potential for improved heat transmission and its cost for pressure loss. The TPF may reach a maximum of 2.82 compared to the empty channel when the metal foam layer is inserted with , for , and .

Analysis of Torsional Vibration in a Fractured Poroelastic Half-Space Coated with Metal Foam and Sliding Interfaces

Metal foams are highly useful in industries because of their lightweight, energy and vibration absorption properties. This study investigated the propagation of torsional waves in an elastic layer over a fluid-saturated fractured poroelastic half-space with a metal foam coated layer. It is assumed that the interfaces are in sliding contact with two different sliding parameters. The coated layer is closed-cell aluminium foam. We use the separation variable technique and the Bessel function to solve the equation of motion in different layers. The displacement components are written in terms of the second kind Whittaker functions. Using an asymptotic formulation of the Whittaker function and appropriate boundary conditions, the dispersion equation is derived in terms of the determinant. The control of the vibration due to the metal foam-coated layer is one of the important goals of this study. Also, numerical and graphical analyses have been done with the help of Mathematica software to see the effect of different parameters on torsional wave propagation. It is found that the presence of coated metal foam layer decreases the phase velocity of the torsional wave propagation. The work may be helpful in the seismology, automobile, and aerospace industries.

A method of predicting the two-phase liquid-liquid flow resistance in a horizontal pipe with a layer of metal foam

The study reported here is experimental. Its aim was to determine the method applicable for prediction of pressure losses of an unstable two-phase liquid-liquid system flow through a horizontal pipe with a short section of the pipe containing a metal foam packing. However, the flow disturbance resulting from the presence of foam does not lead to a change in the type of the mixture (as there is no phase inversion) nor a permanent emulsification of the flow system. The calculation procedure developed in the study takes into account both the peculiarities that accompany the flow of a two-phase liquid-liquid system in an empty pipe (i.e. type of continuous phase, phase slip, hold-up), as well as geometric parameters of the foam skeleton (i.e. cell and pore dimensions, surface roughness of fibers). The results of experimental research were applied for the purposes of determining the specific form of the equations, consistent with the mathematical model adopted and described in detail in this paper. They were conducted for two foams: aluminum and nickel, which were characterized by the same degree of pore packing (PPI20). The mean dimensions of the elements forming metal foams skeletons were determined by computed tomography. The horizontal flow tube had a diameter of 10 mm and the foam packing occupied it only over a a section with a certain length. In the liquid-liquid system pumped to the pipe, the hydrophilic phase was tap water, while the hydrophobic phase was typical machine oil. The adopted range of flux changes of both liquids corresponded to the conditions at which unstable two-phase systems of the W/O, O/W and W+O type were formed in the empty pipe. The pressure loss of the flowing substance was measured in the foam layer. The values of constants and exponents of the adopted model equation were determined separately for single-phase flow and two-phase systems of various types. The results of the statistical evaluation of the performance of the developed dependencies justify their application in the design procedures of selected heat or mass transfer devices. The equations are dimensionless, and therefore, under the conditions of validity, they should also be effective for other liquid-liquid systems, other foams and flow in a pipe with a different diameter. The developed method is based on a new approach to the description of the two-phase flow resistance through the porous material filling the pipe. In addition, it concerns the flow of a liquid-liquid system, which still forms the area that has been tackled in few publications.

Latent heat thermal energy storage in a shell-tube design: Impact of metal foam inserts in the heat transfer fluid side

The improvement of heat transfer in latent heat thermal energy storage (LHTES) system is a crucial task. In the current study, the impact of diverse metal foam (MF) layer arrangements on heat transfer fluid (HTF) within a shell-tube LHTES is explored. Six distinct cases (A-F) with varied MF coverage percentages and layer dimensions were assessed. The local thermal non-equilibrium model was utilized to take into account the PCM and MF temperatures. The finite element method was used for solving the partial differential equations. The impact of MF configurations and inlet pressures (250 Pa, 500 Pa, and 750 Pa) on the thermal energy storage/release was addressed. Cases A-C, featuring a 50 % MF concentration, exhibit shorter melting times than Cases DF, with decreasing MF concentrations. A higher MF concentration improves the melting process due to increased thermal conductivity and lower thermal resistance on the HTF side. Cases DF, with a centralized MF layer and decreasing concentrations from 25 % to 6.25 %, display progressively shorter melting times, suggesting that a lower MF concentration leads to more efficient melting. Solidification times also decrease with increasing inlet pressures across all cases. Reynolds numbers, influenced by average HTF tube outlet velocity, vary substantially across cases and inlet pressure differences. Cases A-C demonstrate similar Reynolds numbers for each inlet pressure difference, while Cases DF show a more pronounced increase in Reynolds numbers as the MF layer is reduced and flow resistance drops. Cases A (50 % MF layer) and F (6.5 % MF layer) provide the quickest charging and discharging times due to their unique combination of MF layer properties and inlet pressures. The study highlights the need to consider MF layer composition and inlet pressure when designing optimal LHTES systems for efficient energy storage/release.

An improved latent heat thermal energy storage using two layers of metal foams

Latent Heat Thermal Energy Storage (LHTES) systems are essential due to their remarkable ability to compactly store significant thermal energy. Their pivotal role extends to various energy applications, prominently including solar heaters and waste thermal energy recovery initiatives. Metal foams have the ability to improve heat transmission and thermal charging of energy storage units dramatically. However, the metal foam cannot store latent heat energy, so the goal is to improve heat transfer by using minimal foam mass. Here, the LHTES is made of several parallel channel enclosures with a square cross-section of 120 mm in height/width. There is a 21 °C temperature difference between the heated channel walls and PCM fusion temperature. In the current study, the influence of the configuration of two metal foam layers was addressed on melting time in LHTES. The idea is to use heavy foam (porosity 0.90) in places where there is low convection and light foams (porosity 0.975) in places with good convection heat transfer to enhance thermal charging and keep the storage weight low. Therefore, three configurations of splitting into half, an L shape division, and splitting diagonally for foam layers were examined. The influence of metal foam configurations on melting volume fraction, thermal energy storage, isotherms, and streamlines was examined. The geometrical configuration of foam layers could significantly influence the thermal charging time and energy storage profiles. The best layer configuration was a horizontal splitting of the enclosure with a light foam layer (high porosity metal foam) at the top. The well-configured foam layer could complete the charging process in 837 s, 32% faster than the same splitting but placing the light foam layer at the bottom.

Enhancement of battery thermal management system using a novel structure of hybrid liquid cold plate

Battery thermal management system (BTMS) is a crucial component of electric vehicles (EVs) as it ensures optimal operating temperature of battery cells, which is critical for battery safety and performance. Among various cooling methods, liquid cooling is the most reliable owing to its high heat transfer coefficient and low power consumption. In this study, a liquid cold plate (LCP) suitable for different ambient conditions was developed, with optimized power consumption and without pre-cooling the coolant. We investigated six different microchannels, including straight, wavy walls, and metal foam-embedded microchannels, in three different ambient conditions (20 °C, 25 °C, and 35 °C) at various coolant mass flow rates (ranging from 2.5 to 17 kg/s). Our results showed that the wavy walls microchannel reduced the maximum temperature by 4–6 °C, depending on the wave amplitude. Additionally, using fully embedded metal foam microchannels resulted in a 14 °C decrease in the maximum temperature compared to that of straight microchannels, while the temperature difference of the battery module remained within an acceptable range. We also found that a thick layer of metal foam in the vicinity of the microchannel walls decreased the battery module temperature by up to 4 °C while reducing the pumping power, especially at low coolant flow rates. Deploying the wavy microchannel reduced the pumping power between 50 and 73%, while a thin layer of metal foam caused a 50% decrease in pumping power.

A comprehensive numerical study on the effectiveness of a rotational-based PTC collector integrated porous foam and PV module

Integrating Photovoltaic modules with Parabolic Trough Solar Collector (PTC) (PTC-PV) is a method boosting the operating performance of the noticed collector. The PTC-PV unit is not only able to maintain the needed thermal energy but also can provide a tremendous amount of electricity. In this study, the exergy and energy outputs of a PTC-PV unit are enhanced by integrating it with porous metal foam and moving the absorber tube rotationally. The studied cases include a PTC-PV unit, rotational PTC-PV (RPTC-PV) unit, rotational PTC-PV unit integrated with ten separate porous metal foam layers (RPTC-PV-SPF), and rotational PTC-PV unit integrated with a uniform porous metal foam layer (RPTC-PV-UPF). Because of identifying the best unit, the consequence of key factors, namely, solar radiation, inlet mass flow level, and inlet temperature on the outputs of the units, are studied respecting thermodynamic rules. Additionally, the effect of nanoparticles mass fraction, the rotational speed, and metal foam thickness on the outputs of the best unit (RPTC-PV-UPF) are evaluated. According to the results, the highest energy and exergy outputs among the simulated cases belong to the RPTC-PV-UPF unit. At the base case condition, the net energy effectiveness of the PTC-PV, RPTC-PV, RPTC-PV-SPF, and RPTC-PV-UPF units is 58.95%, 90.35%, 89.46%, and 91.42%, respectively. Also, the overall exergy efficiency of these units is 8.43%, 3.37%, 9.48%, and 11.89%, respectively. It is found that the VP-1/MWCNT is the best working fluid for the RPTC-PV-UPF unit. By declining the void fraction of MWCNT nanofluid, the overall exergy and energy performance of the system, respectively, elevates by 9.74% and 0.25%. The nanofluid-based RPTC-PV-UPF unit foam thickness of 8 mm, and rotational speed of 0.5 rad/s, has the highest performance among the studied cases from the exergy viewpoint. The energy and exergy outputs of the RPTC-PV-UPF unit at the optimum operating condition are 67.41% and 77.47% higher than that of the PTC-PV unit.

Hydrogen charging in AX21 activated carbon-PCM-metal foam-based industrial-scale reactor: Numerical analysis

A computational fluid dynamics (CFD) model based on the mass, momentum, and energy conservation equations is used to simulate the industrial-scale hydrogen storage in activated carbon (AC: AX-21) bottle surrounded by a layer of metal foam (MF)-phase change material (PCM: RT 22 HC) latent thermal unit. The aim is to boost the recuperation (storage) of the heat liberated from the H₂‘s exothermic (adsorption). Following the model's validation, several numerical simulations were performed to evaluate the impact of various physical features of the MF (copper), at variable porosity (ε = 0.80–1.0), on heat transfer in the hole reactor. Independently of the MF porosity, the AC-bed temperature suddenly increased (from 295 K), reaching a maximum (at about 500 s) and decreased afterward. The temperature's intensity was dependent on the probe's position in the AC-bed (i.e. several positions were studied). The H2 concentration in the AC-bed may reach 25 mmol/g. The PCM-based unit received the discharged heat from the AC-bed slowly, but with PCM incorporation in MF, the heat was quickly recovered (stored). Thanks to the MF-induced PCM's increased thermal conductivity, the heat flux, the heat transfer coefficient, and the melting rate of the PCM were all accelerated (during the charging phase) several times by decreasing the MF porosity (increasing MF mass) from 1 (pure PCM) to 0.8. The temperature and the melting contours throughout the absorption process (up 10,000 s) supported all these findings. It is obvious from the results of the current study that improving the reactor geometry and the solid bed's thermal conductivity (thermal performance) is necessary for an effective hydrogen storage system.

Boiling Heat Transfer in Copper Foam Bilayers in Positive and Inverse Gradients of Pore Density

Gradient metal foam is an advanced heat transfer material that decreases resistance to bubble escape and enhances the transfer of boiling heat. In this study, boiling heat transfer and bubble behavior were studied in an experimental set-up with copper foam bilayers configurated either in positive or inverse gradients, utilizing deionized water as working fluid. Positive gradient refers to arranging metal foam layers with high pore density at the bottom, above the heat source, and low pore density on the top. Results show that the heat transfer is higher for gradient metal foam surfaces, of 6.14×105 W/m2, versus a uniform metal foam surface, of 3.94×105 W/m2. For the positive gradient configuration, boiling heat transfer performance first increased with the pore density, then decreased when the pore density was higher than 60 pores per inch (PPI). By contrast, for the inverse gradient, the heat transfer performance was nearly constant with increasing pore density. At the low pore density, the inverse gradient performed better than the positive gradient during the whole boiling process. At high pore density, the positive gradient structure performed better in heat transfer at the early boiling stage. Three main types of bubble escape were observed: For the positive gradient bilayer, the bubbles moved up or down without lateral interference. In contrast, for inverse gradient, the bubbles mostly escape from the sides, which is easy to induce bubble merging. The inverse gradient surface generates larger bubbles, while the positive gradient surface produces a higher frequency of bubble detachment. Accordingly, two liquid replenishment models are proposed: for the positive gradient, external liquid replenishes from the side into the copper foam, while for inverse gradient, the liquid is mainly replenished from the top.

Latent heat thermal energy storage in a shell-tube: A wavy partial layer of metal foam over tubes

The melting thermal energy storage and heat transfer of paraffin wax in a storage unit was modeled in the presence of a wavy copper foam. The phase-change energy and natural convection effects were modeled using the enthalpy porosity approach. The control equations were solved using the finite element method over a structured mesh. The energy storage was simulated for the wavenumber and amplitude of the foam layer. It was found that the higher wavenumber, the shorter the charging time and better energy storage power. A lower wave magnitude was also better than a longer wave magnitude. The shortest melting time was obtained for a flat foam layer, which was 20 % better than a low wave long amplitude foam layer. The current work intends to reduce the weight of applied metal foams in thermal energy storage applications by enhancing the geometry design. Here, a wavy form layer of metal foam was used to guide the natural convection flows and also boost the heat transfer mechanism. The phase change heat transfer has not been investigated in a wavy form metal foam layer.

Numerical investigation and optimization of melting performance for thermal energy storage system partially filled with metal foam layer: New design configurations

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.

Dynamic melting in an open enclosure supported by a partial layer of metal foam: A fast thermal charging approach

A new design of fast charging latent heat thermal energy storage (dynamic melting) is proposed to further reduce the charging time. The proposed new design benefits from a stream of pressurized and heated liquid PCM entering and leaving the storage unit. Two layers of metal foam were also added to accelerate the thermal charging process further. The governing equations for the flow and heat transfer with phase change were introduced as partial differential equations and integrated using the finite element method. The impact of the porosity of foam layers, the foam ratio, and the geometrical placement of layers was investigated in the proposed design. The mounting location of a horizontal foam layer was not much important. Interestingly, it was found that a metal foam with high porosity produces a short thermal charging time. It was since the most important parameter in controlling the thermal charging time was forming a liquid PCM film between the inlet and outlet ports of the enclosure. Such as liquid film allows a passage for the pressurized and heated liquid PCM enters the enclosure and accelerates the melting process by a mixed convection mechanism. A full melting could be achieved in about 2.5 h in a 16-inch diameter enclosure.

The influence of the metal foam layer shape on the thermal charging response time of a latent heat thermal energy storage system

In the current study, the impact of various foam shapes and configurations was addressed for the first time on the thermal energy storage rate. A partial layer of metal foam was used to improve the heat transfer rate in a channel-shaped latent heat thermal energy storage unit for solar thermal energy storage. The channel was heated at the right vertical wall while half of the channel was filled with a layer of metal foam. The enthalpy porosity model was utilized for simulating the melting heat transfer in the channel. The finite element method was employed to solve the governing equations. Several design configurations for the placement of the metal foam layer were examined. The findings showed that placing the metal foam layer in an L shape form along the left and bottom walls could yield maximum thermal energy storage power (0.57 kW). Diagonal placement of the porous layer along the right and bottom walls gives the lowest thermal energy storage power (0.23 kW). Therefore, changing the shape of the metal foam layer could alter the storage power by about 60 % for a fixed amount of metal foam. Therefore, the shape of the metal foam layer is an important design parameter that should be selected carefully.

Multi-variable optimization of metal hydride hydrogen storage reactor with gradient porosity metal foam and evaluation of comprehensive performance

Hydrogen storage performance for metal hydride (MH) reactor is restricted by the poor thermal conductivity of MH. In this study, the gradient porosity metal foam was added into MH reactor for enhancing heat transportation (GMF reactor), and its hydrogen absorption performance was investigated numerically in detail. Then, thermal resistance analysis was conducted to analyze the heat transportation in GMF reactor, and Genetic Algorithm was applied for optimizing metal foam distribution under different conditions. It was indicated that the hydrogenation performance for optimized two-layer GMF reactor was increased by 11.5% compared with uniform metal foam reactor (UMF reactor). The optimization results indicated that the optimal volumetric fractions of metal foam (VFMF) are about 0.08 for both optimized GMF reactor and UMF reactor with the trade-off of hydrogen storage capacity and hydrogen absorption rate. Then, a new indicator of comprehensive hydrogen storage performance (CHSP) for MH reactor was proposed, which includes the influence of hydrogen storage rate, hydrogen storage capacity, volumetric storage density and gravimetric storage density. Besides, the hydrogenation performance for optimized GMF reactor was improved with metal foam layer increasing, and the optimal porosity distribution was gradually approaching a specific power exponent trend. It was showed that the hydrogenation performance for power-exponent GMF reactor was increased by 2.8% and 18.2% compared with that of optimized four-layer GMF reactor and UMF reactor, respectively.

Utilization of a phase change material with metal foam for the performance improvement of the photovoltaic cells

This study presents a novel configuration for improving the photovoltaic (PV) panel's thermal management system, which includes a phase change material (PCM) with the metal foam layer. During the energy-absorbing mode, the arrangement allows for quicker heat dissipation from the system, resulting in the cooling of the PV panels. The effects of the foam-layer material, PCM thickness, and foam porosity are numerically simulated and analyzed. The results demonstrated that the higher PCM layer thickness leads to a lower PV surface temperature. The extracted curves indicated that lower porosity causes higher maximum PV temperature. Furthermore, it was found that average electrical efficiency for the model with a porosity of 0.9, 0.8, 0.4, and no-foam state are 13.805%, 13.794%, 13.761%, and 13.714%, respectively. All data are almost similar for both copper and aluminum foams, and there are negligible differences between the results. The results for the four chosen months describe that for June, March, and September, the PCM layer absorbs heat and causes a considerable reduction in the PV maximum temperature, but for December, this process is not valid. Accordingly, superior PCM-based thermal management is achieved through the proposed system.