Foam Heat Sink Research Articles

Thermal Performance Analysis of Gradient Porosity Aluminium Foam Heat Sink for Air-Cooling Battery Thermal Management System

The three dimensional thermal model of a forced air-cooling battery thermal management system (BTMS) using aluminium foam heat sink (AFHS) is established, and the effects of porosity, pore density, and mass flow rate on the thermal and flow performance are discussed numerically from the aspects of pressure drop and temperature control effectiveness. The results reveal that an AFHS can markedly reduce the battery temperature compared with the BTMS without AFHS, but it also causes huge pressure loss and increases the temperature difference between the upstream and downstream of the battery. Reducing the porosity of aluminium foam reduces the battery’s average temperature, but increases the temperature difference. The increase of pore density leads to the increase of pressure drop, but has little effect on the battery temperature. Based on this, a study of the gradient porosity of the AFHS is carried out, and the thermal and flow performance are compared with the homogeneous AFHS. The results show that the AFHS with porosity-increasing gradient pattern (PIGP) in the direction perpendicular to flow reduces the pressure loss and improves flow performance. The AFHS with a porosity-decreasing gradient pattern (PDGP) in the flow direction has no obvious effect on the flow characteristics, but it can reduce the temperature difference of the battery. The direction of gradient porosity can be selected according to need. In addition, due to the energy absorption characteristics of aluminium foam, AFHS can improve the crashworthiness of the battery pack. Therefore, AFHS has great potential in air-cooled BTM.

Wearable Thermoelectric Cooler Based on a Two-Layer Hydrogel/Nickel Foam Heatsink with Two-Axis Flexibility.

A wearable thermoelectric cooler (w-TEC) shows promising prospects in personal thermal management due to its zero emission, high efficiency, lightweight, and long-term stability. The flexible heatsinks are able to promote the cooling effect of coolers, but the cooling capacity of current coolers still has much room for improvement because of the relatively large thermal resistance between the cooler and heatsink. In this work, the two-layer heatsink units composed of hydrogel and nickel foam are fabricated and attached to a thermoelectric cooler via the thermal silica gel. Thanks to the high thermal conductivity of nickel foam and a tight bond between the hydrogel and nickel foam, effective heat conduction from the cooler to the body of the heatsink was achieved. In addition, the discrete heatsink units endow the w-TEC with excellent flexibility. The bending radius of this w-TEC is as small as 7.5 mm, and a long-term temperature reduction of ∼10 °C can be realized at an input current of 0.3 A for a flat or bent w-TEC. In the on-body testing, a stable temperature reduction of 7 °C can be obtained using an AA battery with an input voltage of 1.5 V.

Bi2Te3-based wearable thermoelectric generator with high power density: from structure design to application

For the optimized TEG, heat collection with a copper film at the skin end and a copper foam heat sink at the air end were installed to improve the power generation performance of the TEG. When the wearer is running outdoors, the power density is 138.46 μW cm−2.

Lattice Boltzmann Method simulation of flow and forced convective heat transfer on 3D micro X-ray tomography of metal foam heat sink

Fluid flow and thermal distribution in isothermal forced convection heat transfer through metal foams are studied. The true geometry of the metal foam samples are obtained by Micro-Computed Tomography (micro-CT) scanning. The Lattice Boltzmann Method (LBM) is used to calculate fluid flow and heat transfer in environments with high geometric complexity. The flow field and the temperature field are solved using the Multi-Relaxation Time (MRT) and Bhatnagar-Gross-Krook (BGK) collision schemes, respectively. The three-dimensional forced convection heat transfer in five metal foam samples with different pore densities (5, 10, 20, 60 and 80 PPI) as well as various porosities (73.69–92.37) in the Reynolds number range of 50–1000 considering two different fluids with Prandtl numbers of 0.7 and 7.0 are analyzed. The correlations between the flow and the heat transfer in metal foam samples are discussed based on numerical results. The results showed that the properties of the foam samples are more responsive to the variations of porosity than the pore density. Conversely, velocity profile and local Nusselt number are directly affected by the pore density. The numerical method developed in this work is able to predict the flow characteristics and heat transfer at the pore scale in the reconstructed geometry of porous structures of real samples.

Semi-analytical study of impingement cooling of metal foam heat sinks of CPUs with air and hydrogen jets under LTNE condition

In this paper, a mathematical model for heat transfer in a heat sink covered by an open-cell metal foam under impinging jet flow is presented. Hydrogen and air were considered as the cooling fluids. The Darcy–Brinkman–Forchheimer relationship for the momentum equation was employed, while the two-equation energy model under the local thermal non-equilibrium (LTNE) condition for the energy equation was used. The mathematical model of similarity solution was first validated with analytical and experimental data from literature, and numerical data from Ansys-Fluent®. Then, the differences between numerical predictions under the local thermal equilibrium (LTE) and LTNE on flow and temperature distributions were presented and analyzed. It was shown that when the effective thermal conductivity of solid is very low, the difference of temperature of solid and gas cannot be neglected and LTNE should be considered. In other words, when effective thermal conductivity ratio, β, declines, the deviation between the LTNE and LTE models increases considerably. Finally, the effects of critical dimensionless parameters on the flow and heat transfer characteristics were investigated. The results indicate that cooling performance of the metal foam can be improved by increasing the Reynolds and Darcy numbers while decreasing the aspect ratio of the heat sink. Besides, the properties of metal foam and gas were studied. Hydrogen, as a cooling gas, has better thermal performance than air.

Cooling of high-performance electronic equipment using graphite foam heat sinks

In the present research, highly-conductive graphite foams have been employed to effectively dissipate the heat generated in electronic components. The heat sinks suggested have been configured from staggered foamed-baffles arranged either in parallel or perpendicular to the air paths through the slots in between to reduce the pressure drop resulted while improving the heat dissipation. The performance of the currently proposed heat sinks has been examined numerically based on the volume averaging concept of porous media, with employing the local thermal non-equilibrium model to account for the interstitial heat exchange between the foam solid matrix and the fluid particles flowing across. The Simcenter STAR-CCM+ CFD commercial code has been utilised to implement the iterative solution based on the SIMPLE algorithm. A wide range of design parameters have been tested including the heat sink configuration along with geometrical characteristics of the graphite foam used. The impact of operating conditions, including the inlet airflow strength and the heat flux applied, has been inspected as well. The currently proposed heat sinks have been found efficient to meet the extremely thermal demands of high-performance electronic equipment and sweep away the heat generated there with a reasonable cost of pressure drop, where hot spots can be eliminated entirely with proper manipulation of design conditions.

A Review of Thermo-Hydraulic Performance of Metal Foam and Its Application as Heat Sinks for Electronics Cooling

AbstractHigh porosity metal foams offer large surface area per unit volume and have been considered as effective candidates for convection heat transfer enhancement, with applications as heat sinks in electronics cooling. In this paper, the research progress in thermohydraulic performance characterization of metal foams and their application as heat sinks for electronics cooling are reviewed. We focus on buoyancy-induced convection, forced convection, flow boiling, and solid/liquid phase change using phase change materials (PCMs). Under these heat transfer conditions, the effects of various parameters influencing the performance of metal foam heat sink are discussed. It is concluded that metal foams demonstrate promising capability for heat transfer augmentation, but some key issues still need to be investigated regarding the fundamental mechanisms of heat transfer to enable the development of more efficient and compact heat sinks.

Thermal management of power electronics with liquid cooled metal foam heat sink

In this paper, a combined experimental and numerical study of liquid cooled aluminum foam (AF) heat sink applicable for high power electronics cooling was conducted. AF heat sinks with porosity (0.88) and pore densities (10 PPI and 20 PPI) are fabricated and the empty channel is employed for comparison. Experimental measurements were conducted subjected to non-Darcy flow regime. Numerical analysis was based on the Brinkman-Forchheimer extended Darcy momentum model, together with the energy equations of local thermal non-equilibrium (LTNE) and local thermal equilibrium (LTE) models. The permeability and inertia coefficient of the AF samples were correlated based on the measured pressure drop. New correlations of interfacial heat transfer coefficient between water and AF solid matrix were also determined. Numerically predicted local surface temperature and temperature field distributions were presented and validated with the experimental measurements. The results reveal that the permeability decreases and the inertial coefficient increases with increasing pore density. The thermal performance of AF heat sinks is appreciably superior to the empty channel, under a given flow rate, the Num of the AF heat sink can be 1.40–1.76 times of the empty channel. Heat transfer enhancement by 20 PPI foam is inappreciable, approximately 5%, compared to that of 10 PPI. The LTNE model demonstrates more accurate for predicting the spatial temperature distributions than the LTE model. The results also indicate that the non-equilibrium heat transfer phenomenon in water-cooled AF heat sink is not pronounced, and the non-equilibrium effect is declined with increasing velocity.

Thermal performance of lithium-ion batteries applying forced air cooling with an improved aluminium foam heat sink design

A lithium-ion battery thermal management system using forced air cooling with open-cell aluminium foam was proposed in this paper. The battery module consists of eight pieces of pouch cell and nine pieces of aluminium foam heat sink. The battery module thermal model was developed to analysis its thermal characteristics. Thermal interaction between battery cells in this model was explored. The effects of porosity and pore density of aluminium foam on the heat dissipation performance at different mass flow rates were investigated. The results show that the thermal interaction between battery cells becomes more obvious after using aluminium foam. Metal foam can significantly reduce battery temperature rise compared with the pure air-cooled system, but it will cause huge flow resistance and pressure loss, which will easily lead to uneven temperature distribution on the battery surface. Additionally, decreasing the porosity of aluminium foam decreases the average surface temperature of batteries, but increases temperature difference. To improve temperature uniformity, the cooling air flow direction, the layout of battery module and the shape of aluminium foam were also studied. Our results showed that the case with quarter inlet width and "T" shape aluminium foam exhibited the most excellent performance among all cases. Despite the mentioned defects, applying aluminium foam is still a promising method in battery thermal management system. And this paper provided a theoretical reference for designing aluminium foam thermal management system in batteries.

Numerical evaluation of additively manufactured lattice architectures for heat sink applications

Tailoring the architectural characteristics of lattice materials at different length scales, from nano to macro, has become tenable with emerging advances in additive manufacturing. Cumulative needs of high heat dissipation rates and structural requirements along with lightweight constraints have led to the development of several heat sink fins with lattice architectures in heat exchange-applications. Here, we numerically investigate the potential of polymer-based 3D printed lattice architectures as extended heat transfer surfaces and examine the forced-convection characteristics of simple-cubic, body-centered-cubic and face-centered-cubic trusses as well as simple-cubic plate, and Kelvin and Octet periodic lattices with mesostructured architecture. All these lattices have a porosity of 77% (relative density ~23%) and surface area density in the range of 1500−2400m2/m3. Thermal and hydraulic finite element studies were conducted for fluid flow over the lattice architectures for low Reynolds number in the range of 50−360 and constant wall temperature conditions. The performance of different cell-topologies is characterized in terms of exit fluid temperature, heat transfer coefficient with respect to different reference surface areas, pressure drop per unit length, Colburn factor j, Fanning friction factor f and area goodness factor j/f. The study of the influence of thermal conductivity on heat transfer rate reveals that the polymer-based architected heat sinks perform close to their metallic counterparts when evaluated on per unit mass basis. Furthermore, body-centered-cubic truss, simple-cubic plate, and Kelvin and Octet lattice-cells were found to exhibit better thermal performance than some microchannel and open-cell foam heat sinks.

Multi-objective optimization of finned metal foam heat sinks: Tradeoff between heat transfer and pressure drop

In several research fields, e.g., the miniaturization of electronic components, new solutions for heat management are required and metal foam heat sinks can be a worthy solution. These latter provide the crucial challenge of heat transfer augmentation by limiting pressure drops, which presents a typical multi-objective optimization problem. In this background, the paper deals with both non-finned and finned metal foam heat sinks by numerically investigating thermo-fluid-dynamics to maximize heat rate and minimize pumping power. The governing equations of the problem are written by using the porous media theory under the assumptions of local thermal non-equilibrium. They are solved under appropriate boundary conditions with a finite element commercial code, i.e., COMSOL®. The closing coefficients for porous media equations are calibrated with reference to previous experimental studies, with discrepancies lower than 10% for both heat rate and pumping power. The numerical model is coupled with a MATLAB® multi-objective genetic algorithm by applying a Pareto approach that provides optimal tradeoff solutions for the two objective functions, i.e., heat rate to be maximized and pumping power to be minimized. Different morphological, geometrical and fluid-dynamic parameters are considered as design variables. It is shown that the finned metal foam heat sink can enhance dissipated heat rates of about 3.3–3.5 times the metal foam heat sink, at equal pumping power. By performing comparisons with experimental data, optimization process is shown to enhance heat rates at fixed pumping power of about 2.5–3 times and 5–6 times for metal foam and finned metal foam heat sinks, respectively. Finally, dimensionless correlations of the Pareto fronts are presented to drive the design of such optimized devices.

Analysis of Fluid Flow and Heat Transfer in Corrugated Porous Fin Heat Sinks

This study reports on a mathematical model for predicting the fluid and heat flow characteristics of a Z-shaped corrugated foam heat sink. Experiments were carried out to validate local as well as overall pressure drop predictions. The mathematical model was further validated against corrugated carbon foam experimental measurements from the literature. A general flow parameter emerges from the formulation that is descriptive of flow uniformity. Based on a scaling analysis, it was found that a relatively low permeability foam, compared to the square of the conduit hydraulic diameter, is more effective than high permeability foam because of its ability to achieve uniform flow distribution. An illustrative study is carried that estimates the optimum number of porous fins that can be packaged within a given volume under fixed pressure drop constraint. Further, this study elaborates on the importance of achieving uniform flow distribution across the porous fins. The ideal condition of uniform flow was found to be useful in increasing the rate of heat transfer when compared with the actual condition of non-uniform flow for the range of parameters explored in this work. Finally, the impact of the flow non-uniformity parameter on the overall Nusselt number is illustrated.

High porosity and light weight graphene foam heat sink and phase change material container for thermal management

During the last decade, graphene foam emerged as a promising high porosity 3-dimensional (3D) structure for various applications. More specifically, it has attracted significant interest as a solution for thermal management in electronics. In this study, we investigate the possibility to use such porous materials as a heat sink and a container for a phase change material (PCM). Graphene foam (GF) was produced using chemical vapor deposition (CVD) process and attached to a thermal test chip using sintered silver nanoparticles (Ag NPs). The thermal conductivity of the graphene foam reached 1.3 W m−1 K−1, while the addition of Ag as a graphene foam silver composite (GF/Ag) enhanced further its effective thermal conductivity by 54%. Comparatively to nickel foam, GF and GF/Ag showed lower junction temperatures thanks to higher effective thermal conductivity and a better contact. A finite element model was developed to simulate the fluid flow through the foam structure model and showed a positive and a non-negligible contributions of the secondary microchannel within the graphene foam. A ratio of 15 times was found between the convective heat flux within the primary and secondary microchannel. Our paper successfully demonstrates the possibility of using such 3D porous material as a PCM container and heat sink and highlight the advantage of using the carbon-based high porosity material to take advantage of its additional secondary porosity.

A phase change/metal foam heatsink for thermal management of battery packs

Heat transfer and phase change flow inside a Li-ion battery enclosure filled with a copper metal foam embedded in paraffin wax phase change material (PCM) are studied numerically. For simplicity and due to the axisymmetric of the enclosure geometry, half of the battery cell is considered as the heat source on the right wall. The vertical walls are considered symmetric, while the bottom wall is insulated, and the top wall is subjected to the convective heat transfer. The governing equations of the flow and heat transfer are presented as partial differential equations and then transformed into non-dimensional forms and solved by employing the finite element method. The local thermal equilibrium model was used, which limits the model to metal foams with high pore densities. For validation, results are compared with some of the well-known studies in the literature. The isotherms and streamlines are presented for three levels of heat pulse intensity. Both melting and solidification occur as a result of the unsteady heat pulses induced by the thermal source. The vertical location of the battery inside the enclosure can affect the streamlines and isotherm contours. Results show that for higher heat pulse powers, the melt volume fraction (MVF) increases, and heatsink will have higher efficiency. For a comparatively strong heat pulse, the efficiency was increased about seven times.

Thermal Performance of Metal Foam Heat Sink With Pin Fins for Nonuniform Heat Flux Electronics Cooling

Abstract In this paper, a concept of metal foam heat sink with pin fins (MFPF heat sink) is proposed to improve the cooling performance of high-powered electronics with nonuniform heat flux. Numerical simulations are carried out to investigate the thermohydraulic performance of MFPF heat sink, and the metal foam (MF) heat sink and traditional pin fin (PF) heat sink are employed for comparison. The capability of MFPF heat sink in handling nonuniform heat flux is examined under different power levels. It indicates that the MFPF heat sink greatly enhances the heat transfer performance, due to the common effects of the improved flow distribution and enhanced overall effective thermal conductivity (ETC). Results also show that the MFPF heat sink promotes the improvement of the bottom wall temperature uniformity. Porosity has more pronounced effects on heat transfer performance of MFPF heat sink than pore density. A nonuniform distribution heat flux (15–80–15 W/cm2) can be successfully dissipated using the proposed MFPF heat sink with the junction temperature below 95 °C at Re of 500.

Influence of Changing Porosity and Height of Fins on Thermal Performance of The Metal Foam Heat Sink: Numerical Investigation

Abstract— With the major advances in technology, the extreme need for more powerful and efficient electronic devices and equipment has increased, that is requiring more heat generation as a result. So, it is necessary to find a cooling method commensurate with heat generated. This leads to the use of the foam heat sink which is considered as one of more powerful cooling methods for this purpose. The target of this work is to numerically investigate the impact of changing the porosity and the ratio between height of the fin respect to its length on base temperature and heat transfer coefficient in the case of natural convection conditions. The dimensions of the foam fins were 100 * 10 in mm (length * width) and the spacing between fins was 8 mm, while the height of fins was variable with ratio ranging from 0.2 to 2.4. The porosity of model was changing from 0.95 to 0.71 with fixed pore density of 10 PPI. The investigations have been performed by using ANSYS Fluent software (R16.1) and the model of a local thermal non-equilibrium (LINE) has been used in the analysis where, the temperature of the solid part in foam matrix and the fluid are solved individually in energy equation. The heat fluxes were various from 4 to 30 W, and air has been used as a working fluid. The results showed that the average improvement in base temperature of the heat sink is 16.7 %, and the maximum enhancement of heat transfer coefficient reaches about 21.3%, when the porosity reduced from 0.95 to 0.79. The highest enhancement in base temperature and heat transfer coefficient obtains when the height to length ratio is (2.2) and estimated by 30 % and 83.8% respectively, compared with the ratio of (0.2).

Analysis of hydro-thermal and entropy generation characteristics of nanofluid in an aluminium foam heat sink by employing Darcy-Forchheimer-Brinkman model coupled with multiphase Eulerian model

The efficiency and the operational life of the modern high-tech electronics are essentially dependent on their effective thermal management. The metal foam heat sinks cooled by nanofluid are the potential candidate for electronic cooling applications. Therefore, this study investigates the hydrothermal and entropy generation aspects of nanofluid in an aluminum foam heat sink. The multiphase Eulerian model couple with the Darcy-Forchheimer-Brinkman model was introduced to model nanofluid in the metal foam. The performance of nanofluid dependent on substrate porosity and nanoparticles is analyzed for porosity and Reynolds number ranges of 0.5–0.8 and 600–1800, respectively. The probed nanofluid sample consisted of a 0.5% volume fraction of aqueous-based alumina nanoparticles with 40 nm diameter. The hydrothermal results are evaluated in terms of average Nusselt number, local heat transfer coefficient, pumping power and performance evaluation criteria of the heat sink. Additionally, the fluid dynamics and surface temperature distribution across the heat sink are illustrated with velocity streamlines, velocity, and thermal contours. The entropy generation aspects are discussed in the form of thermal, viscous and total entropy parameters. The results demonstrate that the heat transfer enhancement of the nanofluid is optimized by increasing the substrate porosity at the expense of the least pressure drop. The effect of media permeability on the performance of the nanofluid is more evident at a larger Reynolds number. At the Reynolds number of 1800, utilization of the nanofluid resulted in the maximum Nusselt number enhancement of 5%, 15% and 33% for the foam porosities of 0.5, 0.7 and 0.8, respectively.

MHD forced convection of nanofluid flow in an open-cell metal foam heatsink under LTNE conditions

In this paper, nanofluid forced convective heat transfer through an open-cell metal foam heatsink under a uniform heat flux, numerically has been investigated. A uniform magnetic field has been applied to the nanofluid flow. For the momentum equation, Darcy–Brinkman model and, for the energy equation, two-equation model under the condition of fully developed from the thermal and hydrodynamical standpoints have been used. In recent study, by utilizing a numerical method, an attempt was made to avoid a complete and complex CFD approach. To validate the results, the dimensionless parameters such as non-dimensional velocity and temperature, pressure gradient and Nusselt number have been compared with previous researches and a good agreement appeared. Eventually, the effects of different dimensionless parameters such as porosity, Hartman number, nanofluid volume fraction, Reynolds number, thermal conductivity ratio and pore density on the hydrodynamical and thermal characteristics of heatsink have been investigated. The outcomes show that the rise of pore density and Hartman number and the decline of the porosity will enhance the thermal performance; however, it also will reinforce the resistance to the flow through the porous media. Focusing on results illustrates that Nusselt number variation for increasing porosity from 0.85 to 0.95 at the minimum and maximum of the pore density are $$\left( {\Delta {\text{Nu}}_{{\left(\upvarepsilon \right)}} } \right)_{{\upomega = 10}} = - 331.7$$ and $$\left( {\Delta {\text{Nu}}_{{\left(\upvarepsilon \right)}} } \right)_{\omega = 60} = - 367.8$$ , and these values for friction factor are equal to $$\left( {\Delta f_{{\left(\upvarepsilon \right)}} } \right)_{{\upomega = 10}} = - 22.3$$ and $$\left( {\Delta f_{{\left(\upvarepsilon \right)}} } \right)_{{\upomega = 60}} = - 793$$ , respectively. On the other hand, increasing Hartman number from 0 to 100 would change the Nusselt number and friction factor as $$\left( {\Delta {\text{Nu}}_{{\left( {\text{Ha}} \right)}} } \right)_{{\upomega = 10}} = 9.4$$ , $$\left( {\Delta {\text{Nu}}_{{\left( {\text{Ha}} \right)}} } \right)_{{\upomega = 60}} = 0.2$$ , $$\left( {\Delta f_{{\left( {\text{Ha}} \right)}} } \right)_{{\upomega = 10}} = 213$$ , and $$\left( {\Delta f_{{\left( {\text{Ha}} \right)}} } \right)_{{\upomega = 60}} = 211$$ , respectively. The amount of Hartman and Reynolds numbers effects on the heat transfer rate depends on the pore density. In other words, when the pore density becomes saturated, the effects of these parameters decrease. In addition, the use of nanofluid will improve the heatsink thermal performance.

Enhancing the performance of aluminum foam heat sinks through integrated pin fins

In this paper, the fluid flow and heat transfer performances of aluminum foam heat sink with pin fins (AFPF heat sink) are experimentally and numerically investigated. High porosity aluminum foams with the porosity of 0.88 and pore densities of 10 PPI and 20 PPI are incorporated into the pin fin array channel to form the test sections. The channel consists of five rows of 5 mm × 5 mm square cross-section staggered pin fins with height of 13 mm. The AFPF heat sinks are subjected to the steady water flow covering the Darcy-Forchheimer regime, and measurements of the flow and heat transfer are performed and compared with the aluminum foam (AF) heat sinks. The results show that the insertion of pin fins into the AF heat sink has significant effects on both flow and heat transfer characteristics. Heat transfer performance of AFPF and AF heat sinks both increases with increasing pore density. The improvement of average Nusselt number in AFPF heat sink of 20 PPI is approximately 63.5–68.1% compared to the AF heat sink, while the deduced flow resistance is increased by 49.2–88.1%. The thermal performance of the AFPF heat sink is found to be 1.5 times of the AF heat sink under a given pumping power. In addition, a numerical model capable of predicting the temperature distribution and pressure drop is developed and experimentally validated.

Experimental Study on the Thermal Performance of a Finned Metal Foam Heat Sink with Phase Change Material

The present research conducts an experimental study on the thermal performance of the finned metal foam (FMF) heat sinks with phase change material. The dynamic temperature response of an FMF heat sink is analyzed and compared with the corresponding finned heat sink. The effects of porosity and pore density on the thermal performance of FMF heat sinks are analyzed. Furthermore, the enhancement ratio and heat exchange capability are evaluated for the optimization of FMF heat sinks. The results indicate that the thermal conduction enhancement caused by the addition of metal foam exceeds the heat transfer loss arising from the suppression of natural convection. A decrease in porosity leads to an increase in heat exchange capability and contributes to a higher enhancement ratio. Considering the tradeoff between the low operating temperature and longer duration of reliability, the porosity of 0.9 is the best choice for FMF heat sinks. Though the porosity is identical, the thermal performance of an FMF heat sink is better with the increase of pore density. Considering the maximum energy charging capacities are identical, the FMF heat sink with larger pore density is recommended for practical engineering applications.