Melting Process Of Phase Change Material Research Articles

Simulation and Experimental Investigation of the Effect of Pore Shape on Heat Transfer Behavior of Phase Change Materials in Porous Metal Structures

With the gradual increase in energy demand in global industrialization, the energy crisis has become an urgent problem. Due to high heat storage density, small volume change, and nearly constant transition temperature, phase change materials (PCMs) provide a promising method to store thermal energy. In this work, we designed and fabricated three kinds of porous metal structures with hexagonal, rectangular, and circular pores and explored the phase change process of PCMs within them. A two-dimensional numerical model was established to investigate the heat transfer process of PCMs within different shapes of porous metal structures and analyze the influence of heat source location on the thermal performance of the thermal storage units. Visualization experiments were also carried out to reveal the melting process of PCMs within different porous metal structures by a digital camera. The results show that paraffin in a porous metal structure with hexagonal pores has the fastest melting rate, while that in a porous metal structure with circular pores has the slowest melting rate. Under the bottom heating mode, the melting time of the paraffin in porous metal structures with hexagonal pores is shortened by 18.6% compared to that in porous metal structures with circular pores. Under the left heating mode, the corresponding melting time is shortened by 16.7%. These findings in this work will offer an effective method to design and optimize the structure of porous metal and improve the thermal properties of PCMs.

Investigation of Thermal Performance of Optimized Tree-Shaped Fins in Latent Heat Storage Units

An innovative tree-shaped fin is proposed to address the problem of low thermal conductivity of phase change materials (PCMs) in latent heat energy storage units. Numerical methods are applied to investigate the thermal properties of the melting process of PCMs. This paper investigates the effects of fin arrangement, fin geometry parameters, and temperature of the heat source on melting characteristics of PCMs in the latent heat energy storage unit. Results show that the melting time of PCMs with the inwardly-tilted fins at the top increases by 21.3% compared to the outwardly-tilted fins at the bottom. The response surface methodology is adopted to obtain the fin parameter combination with lower quality and better performance. The optimal fin dimensions are a thickness of 1.06 mm, a length of 3.38 mm, and a spacing of 12.61 mm. The reduction of the ambient temperature from 35 °C to 30 °C increases the melting time of the latent heat energy storage unit by 85%, and from 35 °C to 40 °C decreases the melting time by 29%.

Experimental assessment of the heat shielding performance by the integration of phase change material and liquid cooling plate

This research focuses on innovative stealth equipment by integrating a liquid cooling plate and phase change material (PCM), and the temperature rise on the cold surface and PCM melting rate is reported to illustrate the PCM thermal behavior in lifting the heat shielding performance. Results show that the integrated PCM system is effective in delaying the temperature rise within a certain time. A slower temperature rise on the cold surface is found at the first 1200 s, and a significant acceleration in the temperature rise is given within 1200 s ∼ 2000 s as the heat flood breaks through the PCM layer. The PCM melting rate increases rapidly and then rises slowly, and the complete melting time is shortened as increasing heat power. The heat shielding performance is significantly reduced with increasing the liquid flow rate, and the influence of the coolant temperature on the temperature rise becomes more and more prominent as the completion of the PCM melting process. A slower temperature rise is observed at the lower PCM phase transition temperature, and a further increase in the PCM covering layer has little influence on the temperature rise at the initial stage.

Enhancement of solar evacuated tube unit filled with nanofluid implementing three lobed storage unit equipped with fins

This study discusses an evacuated tube collector-type solar water heater (ETCSWH) using a phase change material (PCM) chamber with fins, nanofluid, and nano-enhanced phase change material (NEPCM). First, the charging phenomena in a horizontal triplex tube heat exchanger (TTHX) equipped with fins, natural convection, and an ETCSWH system without PCM is simulated to validate the solution. The impact of adding fins and nanoparticles with a volume fraction of 3% of Al2O3 and Cu to paraffin wax and water-based fluid, respectively, on the unit's efficiency has been examined. The proposed system for the PCM melting process, heat storage, fluid flow behavior in the system, and velocity distribution and temperature contour in the storage tank and three parts of the absorber tube have been evaluated using ANSYS FLUENT software in a three-dimensional and transient simulation. The results show that Case 8 has improved by 39.7% compared to Case 1 and Case 4 by 5.2% compared to Case 1 within 4 h of the melting process. Also, Case 8 with a 43% and 6.4% shorter melting time than Cases 1 and 5 has the best performance and the greatest heat transfer rate. The productivity of the ETCSWH system is considerably enhanced by the use of fins, NEPCM, and nanofluid.

Energy and exergy analysis of a laboratory-scale latent heat thermal energy storage (LTES) using salt-hydrate in a staggered tube arrangement

The energy and exergy analyses were performed for a laboratory-scale latent heat thermal energy storage (LTES) using hexahydrate calcium chloride (CC6) as phase change material (PCM) in a staggered tube array configuration, placed horizontally. The PCM melting and solidification process within the tube array was investigated by performing a numerical analysis using transient two-dimensional Navier-Stokes equations and Realizable k-ɛ turbulence model to predict flow and heat transfer. The enthalpy-porosity technique was applied to model PCM melting and solidification. The accuracy of the numerical model was validated against experimentally obtained data where the numerically predicted and measured air temperature at the tube array outlet and PCM temperatures were compared. Additionally, the pressure drop in the array and the average peripheral heat transfer coefficient calculated from the numerical results were compared to the well-known Zukauskas correlation (Zu). The results show that the melting and solidification process of PCM in the tubes of the array is asymmetric in nature, with the PCM melting taking slightly longer compared to the solidification process. It was also observed that the energy quantity was higher compared to the exergy quantity, as exergy considers entropy generation and accounts for irreversibility within the system.

Temporal numerical analysis of beeswax PCM melting in a cube geometry subjected to a constant wall temperature condition

The ability of phase change materials (PCM) to store thermal energy has gained wide application area, like battery thermal management, solar water desalination and many other. The melting process of beeswax phase change material within the cube geometry with constant wall temperature (65 °C) boundary condition has been investigated using solidification and melting model. The fluid flow and heat transfer governing equations are solved using second order finite volume scheme. A PRESTO algorithm is applied for pressure-velocity coupling. The convergence criteria of 10−10 have been selected for energy equation, while 10−8 is selected for both momentum and continuity equations. The results like percentage variation along length-height and height-width plane for transient liquid fraction and temperature has been plotted, along with velocity streamlines within the cube geometry. From the obtained results it is concluded that the melting fraction and temperature of beeswax PCM is different in different planes and the major factors which affect the complete melting process is wall temperature, and the geometry. A difference of more than 0.1 °C in temperature has been recorded between mid-length-height and height-width plane while a difference of more than 2% in liquid fraction of PCM is observed. Even the uniformity of temperature and liquid fraction is notably influenced and vary along length, height, and width of cube geometry. Thus, it is concluded that melting process of PCM may affect the ability to store and release the heat energy which further affect the performance parameters of applied physical system.

Boosting thermal regulation of phase change materials in photovoltaic-thermal systems through solid and porous fins

This study explores the integration of porous fins with phase-change materials (PCM) to enhance the thermal regulation of photovoltaic-thermal (PVT) systems. Computational simulations are conducted to evaluate the impacts of different porous fin configurations on PCM melting dynamics, PV cell temperatures, and overall PVT system effectiveness. The results demonstrate that incorporating optimized porous fin arrays into the PCM region can significantly improve heat dissipation away from the PV cells, enabling more effective thermal control. Specifically, the optimized staggered porous fin design reduces the total PCM melting time and decreases peak cell temperatures by about 5°C . This is achieved by creating efficient heat transfer pathways that accelerate the onset of natural convection during the PCM melting process. Further comparisons with traditional solid metallic fins indicate that while solid fins enable 12.2% faster initial melting, they provide inferior long-term temperature regulation capabilities compared to the optimized porous fins. Additionally, inclining the PV module from 0° to 90° orientation can further decrease the total PCM melting time by 13 minutes by harnessing buoyancy-driven convection. Overall, the lightweight porous fin structures create highly efficient heat transfer pathways to passively regulate temperatures in PVT systems, leading to quantifiable improvements in thermal efficiency of 16% and electricity output of 2.9% over PVT systems without fins.

Investigating the Impact of Cell Inclination on Phase Change Material Melting in Square Cells: A Numerical Study.

In order to determine the ideal degree of inclination that should be employed for constructing effective thermal energy storage systems, it is important to examine the impact of inclination angle on the melting behavior of phase change materials (PCMs) such as paraffin wax within a square cell. In consequence, this would guarantee the greatest capacity for energy release and storage. Additionally, analyzing this influence aids engineers in creating systems that enhance heat flow from external sources to the PCM and vice versa. To find out how the cell's inclination angle affects the melting of PCM of paraffin wax (RT42) inside a square cell, a numerical analysis is carried out using the ANSYS/FLUENT 16 software. Specifically, the temperature and velocity distributions, together with the evolution of the melting process, will be shown for various inclination angles, and a thorough comparison will be made to assess the influence of inclination angle on the PCM melting process and its completion. The findings demonstrated that when the cell's inclination angle increased from 0° to 15° and from 0° to 30° and 45°, respectively, the amount of time required to finish the melting process increased by 15%, 42%, and 71%, respectively. Additionally, after 210 min of operation, the PCM's maximum temperature is 351.5 K with a 0° angle of inclination (horizontal) against 332.5 K with an angle of inclination of 45°.

Investigation of phase change heat transfer in a rectangular case as function of fin placement for solar applications

This paper attempts to maximize solar energy utilization by employing a latent heat thermal energy storage (LHTES) unit integrated with a solar receiver of concentrating collectors or thermal management unit for photovoltaic panels. The study investigated an LHTES unit with a rectangular shape and equipped with a T-shaped fin subjected to heat flux. The paper examined the effect of eight T-fin positions under the applied heat flux on the thermal performance of phase change material (PCM). The PCM melting process was modeled using the enthalpy-porosity method using the finite element approach. The obtained numerical results revealed that PCM melting rate strongly depends on fin position, with superiority for fins located at the upper part of the chamber when heat flux is used as the primary heating source. Under applied heat flux, locating the fin at the upper section of the vertical LHTES unit enhanced the melting rate of the PCM, reaching 10 % better than the fin's middle and bottom positions, which is against the cases reported for the fixed temperature heating process that prefer bottom fins. Thus, these results recommend using T-shaped fins in the upper parts of PCM-based units used for solar collector receivers and thermal management of photovoltaic panels.

Empirical Investigation of Thermal Features of Phase Change Material as Thermal Storage System

This paper presents an empirical investigation of the melting processes of phase change material (PCM) in a tube and shell heating exchanger utilizing solar thermal energy. The experiments were conducted outdoors in Al-Mussaib city, Babylon, Iraq (Lat 32.5° North, long 44.3° East), utilizing a north-south (N-S) collector oriented at a tilt angle of 32.5° from the horizontal. This work utilized pure Iraqi black paraffin with 12 kg as PCM. The main empirical rig involves a vacuum tube solar collector (VTSC) utilizing a tube and shell heating exchanger to melt PCM in the shell regime. Different rates of water flow inside the internal heating exchanger's tube, namely (3.5, 5, and 8.5 L/m), were utilized for each season from August 2022 to January 2023. The empirical findings concluded that the internal tube inlet and surrounding temps significantly influence the melting process compared to the rates of water flow. It was found that the melting process of PCM needs about (3 to 4) hours in the summer season. Still, winter needs a longer time, about 14 to 16 hours. Increasing surrounding temp and solar radiation reduces the melting time of phase-change material. The findings of the present work were compared with the earlier investigations and agree with increasing the present work by 23.5 %. The findings from the present study are of practical importance for industries requiring storage materials to improve thermal storage system performance.

NUMERICAL STUDY OF THERMAL MANAGEMENT FOR A CYLINDRICAL HEAT SOURCE BY PCM COMBINED WITH ANNULAR FINS

In the study, annular fins are used to improve the thermal management performance of the phase change material (PCM) towards a cylindrical heat source. A two-dimensional axisymmetric model is established and the influence of fins on the temperature of the heat source is studied in conjunction with the melting process of PCM. The effects of the positions of a single annular fin are investigated. Results show that the lower the individual fin is in the PCM, the faster the melting rate and the lower the temperature, which is because the PCM above the fins can absorb more heat from the upper surface of the fin through natural convection. Maintaining a constant total volume of fins, the effect of multiple annular fins is studied. The results show that multiple annular fins have larger heat transfer areas and more uniform fin distribution, resulting in lower temperature and temperature difference of the heat source surface. Furthermore, the use of multiple fins of unequal height, with bottom fins being higher, is found to be more effective. The best improvement in the thermal management performance of the system is achieved when the height of the fins is 4, 8, and 11 mm from top to bottom, respectively.

Heat management in sonochemical reactor using fins-PCM integrated system: Unveiling the influence of the sonicated volume

With the purpose of enhancing the heat management in the ultrasonic reactor, the present innovative research aims at the exploration of the thermal behavior of sonochemical reactor integrated with fins and phase change material (PCM), focusing on the influence of different liquid heights (LH). The performance of this combination (i.e., sonicated water, fins, and PCM) is investigated for the first time with consideration of the water volume variation. The interplay between fins, liquid height and heat transfer efficiency is explored through detailed numerical analysis of temperature profiles, PCM melt fractions, and enthalpy distributions. The numerical investigation has been conducted using a validated CFD model implemented in ANSYS Fluent® software. The results highlight the significant role of fins in accelerating the PCM melting process and improving heat transfer within the reactor. Notably, fins facilitates efficient conductive heat transfer during the early stages of melting. At t = 1000 s, PCM melt percentages of 22.2 %, 32.6 % and 30 % were attained with fins, compared to 15 %, 18 % and 22 % (without fins), for LH = 5.1, 10.2 and 15.3 cm, respectively. Therefore, LH = 10.2 cm showcased a 43.5 % improvement at this specific time point (1000 s). Moving forward to t = 2000 s, the most favorable melting performance is achieved with LH = 15.3 cm, resulting in a melting percentage increase to 66 % (with fins) compared to 44 % (without fins). Besides, the inclusion of fins results in significant increases of 32.56 % (5.1 cm), 57.6 % (10.2 cm) and 14.4 % (15.3 cm) in PCM enthalpy, while water temperature declined by approximately 4 K for LH = 5.1, 10.2 and 15.3 cm. These outcomes indicate clearly the importance of fins in improving the heat transfer from the irradiated water to the surrounding PCM in the annular space of the reactor.

Three-dimensional numerical simulation of solid-liquid phase change in the cavity of composite structures based on TPMS

Solid skeletons will play an important role in improving the thermal properties of phase change materials. For this reason, the efforts should be dedicated to studying the heat transfer characteristics of solid-liquid phase change with different structural skeletons. In this paper, the composite structures spliced with Gyroid and Diamond skeletons in the horizontal or vertical directions were established by using the Triply Periodic Minimal Surface method. A three-dimensional dimensionless lattice Boltzmann model of the phase change material (PCM) cavity with the spliced skeleton was developed by using the two-region model for solid-liquid phase change in the mushy zone. Based on the pore scale, the phase change heat transfer characteristics under the thermal conductivity ratio of the skeleton to PCM of 100 were analyzed in depth with constant temperature heating at the left wall surface. The results showed that the skeleton spliced in different directions has different effects on the temperature field and heat transfer characteristics of the phase change process. The (G + D)H spliced skeleton which was arranged by Gyroid and Diamond skeletons in the horizontal direction led to a faster melting rate of the PCM than the (D + G)H spliced skeleton which was arranged by Diamond and Gyroid skeletons. The promotion effect of a large porosity skeleton on the melting process of PCM was less than that of a small porosity skeleton. The dimensionless complete melting time for the cavity containing skeleton with porosity ε = 0.915 was increased by 35.7 % and 19.4 % compared to the cavities containing skeletons with porosity ε = 0.826 and 0.871, respectively. This study lays the foundation for the development and application of TPMS spliced skeletons in phase change heat storage and enhanced heat transfer technologies.

Investigation of the thermal exchange mechanism of PCM melting process in an LHTES with elliptic tube configurations inside a cylindrical shell

This study presents a comprehensive 2D numerical investigation into the heat transfer mechanisms and melting time estimation for a phase change material melting process in latent heat thermal energy storage systems. The energy storage system of interest employs an elliptic tube configuration within a cylindrical shell. This study primarily aims to decipher the impact of spatial arrangement and its geometrical intricacies on melting time and the associated heat transfer mechanisms. First, this study examines the transition in the dominant heat transfer mechanisms, from conduction to natural convection, throughout the progression of the melting process. The examination is facilitated using the enthalpy porosity method, which can articulate an additional momentum term by leveraging the porosity at the melting interface and the local liquid fraction. Conduction dominance characterizes the early stages of the melting process; however, a transition toward a complex interplay of natural convection and conduction is observed as the process evolves. When the distance between the heat source and the outer covering is changed from a measure of 0.95 to 0.7, the time it takes for phase change material to melt increases by 73.2%. Additionally, when the shape of a certain heat transfer fluid carrier cylinder and the space between them in angles (from 1/8 to 8 and from 30° to 150°) are adjusted, the melting time changes by 31.1% and 38.9% respectively. In addition to the numerical analysis, this study introduces an innovative predictive model based on artificial neural networks to forecast the melting time of the phase change material in the energy storage system. This predictive model is trained and validated using the data derived from the numerical study and shows good accuracy in predicting the melting time, which is a critical factor for the efficiency and performance of systems.

A novel thermal management system for cylindrical lithium-ion batteries using internal-external fin-enhanced phase change material

This study introduced a phase change material (PCM)-based battery thermal management system (BTMS) using an innovative combination of internal and external fins to create PCM silos around the battery surface, addressing the low thermal conductivity of PCM. The lumped-capacitance thermal model and enthalpy-porosity approach were employed for the battery heat generation and PCM melting process, respectively. The BTMS was evaluated under transient and constant heat generation of the battery at various discharge rates. The effects of fin quantity on thermal management performance, energy density, heat storage capacity, and PCM melting time were investigated. The developed BTMS showed superior performance compared to the battery system with natural air convection cooling and the PCM cooling system without fins. At the end of the PCM complete melting process, the BTMS with 4 internal-external fins decreased the battery surface temperature by 9.90 and 17.45 K compared to the PCM cooling system without fins at the discharge rates of 3C and 5C, respectively. The BTMS with 4 internal-external fins kept the battery surface temperature under the optimum temperature of 318.15 K even at a high ambient temperature of 308.15 K while providing up to 10.02% higher energy density, 11.11% higher heat storage capacity, 32.79% higher fin efficiency, and only 1.08% lower overall fin effectiveness compared to greater fin quantities. The proposed BTMS provided an almost uniform cooling effect on the battery surface compared to the system without fins, which has been largely overlooked in previous studies on BTMSs. Various heat transfer regimes were identified during the PCM melting process. Correlations for predicting the PCM liquid fraction and Nusselt number were proposed as a function of a group of dimensionless numbers. These findings provided valuable insights for designing efficient PCM-based BTMSs.

Toroidal tube latent heat exchanger: An experimental study

Concentric shell and tube latent heat exchangers integrated with phase change material (PCM) are widely used in many heat storage/transfer applications specially for building energy management due to their high energy storage density and fair simplicity in design. However, inadequate phase change in such systems reduces the thermal performance. The innovative geometric design is key in addressing this issue and accelerating the phase change process. The present work reports an experimental effort to investigate the progression of the melting process of PCM inside a novel design of toroidal tube embedded in the system as a shell and tube latent heat exchanger. The experimental setup consists of a toroidal enclosure filled with a bio-based PCM (i.e., coconut oil) and a constant temperature bath as a heat exchange environment. Digital images of melting progression and melting front at three different boundary temperatures (high, middle, and low temperature differences) are captured. Moreover, the time dependent temperature at a selected prob. point is also measured during the phase change process. As expected, decreasing temperature difference, decrease the melting rate, as the experiments show that the completed melting times are 20, 32, and 75 min for the high, middle, and low temperature differences. The melting front is sharper and more distinct to track for higher temperature differences as well. To observe the melting pattern and melting front inside the system (cross-sectional area of the tube) better, the melting progression in different selected times in a half-toroidal tube is also investigated. Furthermore, an extensive uncertainty analysis associated with measuring devices is reported.

Experimental study on heat transfer during melting in metal and carbon foam saturated with phase-change materials for temperature control in electronic devices

Porous media embedded in phase-change materials (PCMs) have been widely applied to thermal management of electronic devices, whereas the influence mechanisms of the suppression of the natural convection of liquid PCM by the porous skeleton and anisotropy of the skeleton on the temperature response of the heat source are still unclear. In this study, an isotropic metal foam and several anisotropic carbon foams are embedded in paraffin and higher alcohol, respectively. The influences of copper-foam skeleton on the PCM natural convection, the evolution of PCM melting front, and the variation of heat-source temperature are studied. The effects of carbon-foam skeleton on the directionality of phase-change heat transfer and the variation of heat-source temperature are investigated. The embedding of metal foam can reduce the heat-source temperature, postpone the onset of PCM melting and the appearance of natural convection, and shorten the PCM melting duration mildly. The anisotropy of carbon foams causes the out-of-plane thermal conductivities of carbon-foam/PCM composites to be larger than the in-plane thermal conductivities. The composite with a low porosity possesses a low melting temperature and short duration of PCM melting process. The increase in ambient temperature causes the time required to trigger the melting of the carbon-foam/PCM composite to decrease but does not affect the melting duration. Conversely, an increase in heat flux reduces the melting duration.

Natural convection of rectangular cavity enhanced by obstacle and fin to simulate phase change material melting process using Lattice Boltzmann method

In recent years, the lattice Boltzmann method has become a powerful method for computational modeling of various complex fluid flow concerns, including the simulation of the melting process in phase change materials. In the present paper, the natural convection of phase change materials in a cavity is simulated, and the effect of adiabatic obstacle and fin is investigated by the lattice Boltzmann method. The obtained results are presented in different Rayleigh numbers (Ra = 103-105), and cavity angles (θ=-90to90) in three scenarios (without adiabatic fin and obstacle, with an adiabatic obstacle, and with adiabatic fin). The investigation across various cavity angles, with adiabatic obstacles and fins, demonstrates a consistent trend of effective melting process delay by up to 50%, underscoring the significant impact of these adiabatic features on PCM behavior. Adiabatic obstacles induce localized melting delays due to unmelted zones around them. Streamlines highlight vortices formed by obstacles, and elevated Nusselt numbers correlate with accelerated melting facilitated by adiabatic fins. Modifying the adiabatic fin height from Yf = 0.1 to Yf = 0.7 leads to a doubling of melting time at around 80% PCM melting. Conversely, decreasing fin height from 0.5 to 0.7 extends the complete melting time by approximately 10%, showcasing the influential role of fin height in shaping PCM melting behaviour.

A novel method to improve the performance of PCM thermal energy storage units using a small oscillator plate-numerical analysis

Employing a small oscillator plate is proposed as a novel idea to improve the performance of phase change material (PCM) based thermal energy storage unit. This idea could make mixing heat flow toward the PCM solid-liquid interface to hasten the melting and heat transfer rates. Opposite to the vibration of the whole PCM heat sink suggested in the literature, it needs very slight mechanical energy for oscillation. The oscillator plate was installed at three positions for the horizontal and vertical PCM heat sink: i) the middle of the hot plate, ii) the bottom of the hot plate, and iii) the corner of the heat sink. A computational fluid dynamics model has been employed to model the PCM melting process and evaluate the induced mixing heat flow and its effect on natural convection. A new mechanical method using vibration energy accelerates heat flow to improve heat transfer and thermal energy absorption. The results reveal that in the best case with transversal oscillation at the corner of the heat sink, the melting rate and heat transfer rate (Nusselt number) increase by 39 % and 64.2 % compared to no vibration case, respectively. Also, the absorbed heat energy rate (AHR) within the PCM heat sink is elevated from 0.51 to 0.79 (54.9 %), while the oscillator just consumed as small as 438 mJ of mechanical energy, reflecting this mechanical approach's uniqueness.

Effects of fin positioning on the thermal performance of a phase change material–filled heat sink with horizontal fins

We conducted numerical simulations to investigate the influence of the horizontal fin arrangement on the thermal performance of a phase change material (PCM)-filled heat sink. Six horizontal fin positions were considered to compare and analyze heat transfer features and variations in the base temperature of the heat sink. The enthalpy–porosity method was used to investigate the phase change process of the PCM and the interface between the PCM and air. The working fluid inside the heat sink was tracked using a volume of fluid model. Heat transfer phenomena during the solid PCM–melting process were examined. The time required to reach the set point temperature (SPT) and storage ratio have been reported for all fin configurations. When the horizontal fins were aligned at the center of the heat sink, the time taken to attain the lowest SPT was the longest and the storage ratio was the highest. In the presence of horizontal fins, the energy storage rate was improved by 3.8 % compared to the case without horizontal fins. In addition, a difference of 2.7 % energy storage ratio appeared depending on the arrangement of horizontal fins, revealing that there exists an arrangement of horizontal fins to effectively store the thermal energy input to the heat sink. The results herein can benefit the thermal management of heat sinks encountered when cooling electronics.