Mode Of Heat Transfer Research Articles

Flow field and heat transfer in the transitional type of turbulent round jet impingement

Jet impingement heat transfer in the transitional type involves the occurrence and disappearance of the secondary maximum heat transfer, which is challenging for numerical simulation. In the paper, the effects of the nozzle-plate spacing H/D on heat transfer and flow fields in the range of 5≤H/D≤7 within the transitional type are investigated. In this type, the secondary maximum heat transfer rate gradually vanishes. In addition, the transitional properties of jet impingement are further discussed. It is found that the heat transfer rate at the stagnation point shows an important relationship with the arriving stream Reynolds number and turbulence intensity. Additionally, three heat transfer modes, i.e., the peak (5<H/D≤5.5), swelling (5.5<H/D≤6.6), and linear modes (6.6<H/D≤7), are identified in the transitional type based on the analysis of the heat transfer rate, development of the intermittency, and the wall shear stress. For the latter two aspects, the laminar zone and the turbulence zone are discussed in detail for different H/D. In the peak mode, heat transfer rate is largely influenced by the transition process, resulting in a secondary peak. While in the swelling mode, the second peak evolves to a swelling and the effect of transition becomes weak. As a result, the influences of the laminar region will extend to downstream. However, in the linear mode, the swelling vanishes with a mild change of intermittency in the boundary layer and the sudden mutation of heat transfer mainly takes place in the stagnation region.

Experimental study on the low-temperature preheating performance of positive-temperature-coefficient heating film in the prismatic power battery module

The performance of a power battery directly affects the thermal safety performance of the vehicle. Aiming at the improvement of thermal safety of lithium-ion batteries under low temperature condition, this study focuses on the effect of the positive-temperature-coefficient (PTC) heating film on the heating performance of batteries through experimental testing. First, the side and bottom of the cell were heated, and the heat transfer path and mode of the single cell were analyzed. The effects of different power densities and geometric positions on the heating effect were studied by testing the heating time and temperature consistency. Second, for the battery module, a low-temperature heating thermal management heat transfer model was built to analyze the heating mechanism of the heating film under different heating power densities. Finally, the results of these studies were synthesized to obtain the optimal heating power density. The results show that for the cell, the optimum power density of side heating and bottom heating is 0.5 W /cm2 and 0.4 W /cm2, respectively. The time required for side heating from −20 °C to 10 °C is 730 s lower than that of bottom heating, and the maximum temperature difference is 1.885 °C lower. For battery modules, a power density of 0.5 W/cm2 was appropriate for both bottom and side heating methods. Due to the existence of heat conduction between battery packs, the battery modules will be quickly and evenly preheated. Under the optimal power density, the time length for side heating from –20 °C to 10 °C was 1459 s, and the maximum temperature difference was 6.32 °C; bottom heating time required slightly more time (1783 s), and the maximum temperature difference was 6.221 °C. Side heating can be beneficial for the rapid preheating of the battery module. This study will contribute to improving the performance and safety of batteries in cold environments.

Energy and exergy analysis of a multipass macro-encapsulated phase change material/expanded graphite composite thermal energy storage for domestic hot water applications

This study presents the development and performance evaluation of an innovative thermal energy storage (TES) system utilizing a commercially available bioderived organic phase change material (PCM) for domestic hot water production. The primary objective of this research is to enhance the efficiency and effectiveness of thermal energy storage solutions by macro-encapsulating the PCM-expanded graphite (EG) compressed modules in a multi-pass tube arrangement. A comprehensive experimental setup was employed to investigate the thermal performance of the proposed TES unit, focusing on charging and discharging cycles. Key findings reveal that conduction is the dominant mode of heat transfer, with the system achieving a significant maximum average charging power of 1440 W and a discharging power of 1990 W. The thermal energy storage capacity reached an impressive 12.6 MJ, enabling the discharge of 90 % of stored energy within 90 min. Furthermore, the exergy analysis indicated high exergy efficiencies, with charging efficiencies reaching 98 % and overall exergy efficiency at 18 %.The implications of this research are significant, demonstrating the feasibility of using bioderived organic PCM for sustainable energy applications. It highlights the potential of the modular structure of the system to integrate with heat pump and solar energy systems, thereby enhancing efficiency and sustainability in domestic hot water applications. This work significantly contributes to the advancement of sustainable thermal energy storage technologies and establishes a solid foundation for future studies aimed at optimizing TES systems for domestic hot water production.

A hybrid experimental configuration for emissivity measurement at cryogenic temperatures

Abstract In cryogenic and high vacuum systems, radiation mode of heat transfer is the primary source of energy interaction owing to the wide temperature differentials and very low temperatures and pressures. Measurement of radiative properties such as emissivity is crucial in the design of cryogenic systems. Emissivity measurement at cryogenic temperatures requires careful consideration of the sample preparation and measurement conditions to ensure accuracy and reliability. Most experimental techniques developed so far are complex in their design and equipment, and they work only on a single measuring method. To address these challenges, this research has proposed a simpler and hybrid experimental setup that could employ both calorimetric and heat flux methods to directly measure the total hemispherical emissivity in the range 90 K–180 K. Experiments were conducted with five types of materials (black paint, stainless steel, aluminum foil, aluminized mylar foil, and copper sheet) by using both methods, and the results were validated with the literature data. The data obtained by calorimetric and heat flux methods for each sample showed a high level of consistency with each other, with a variation of only ±1.5%. Moreover, the discrepancy between the measured and literature data was within the acceptable range of 0.3%–10%. The total hemispherical emissivity of mechanically treated copper was higher than that of chemically polished copper by 11%. This simplified setup has incorporated all possible means to minimize heat leakages into and from the cryostat while maintaining accuracy. The obtained data can be used to accurately estimate the radiation heat loads in cryopumps and other cryogenic systems that use similar components.

Experimental and numerical investigation of heat transfer modes on pot surfaces in a power range of a cooking porous burner

The investigation of convective and radiative heat transfers to a cooking pot in a porous burner, coupled with an analysis of the pot's bottom and side contributions to total heat transfer, remains an underexplored area of research. In this study, we adopt a comprehensive approach, combining experimental measurements and 3D numerical models, to explore the practical application of a Silicon carbide porous burner fueled with natural gas in cooking pots with power ranging from 12.15 kW to 31.04 kW. Three primary aspects are examined: differentiating between radiative and convective heat transfer contributions, investigating porous mixing characteristics, and analyzing the burner's thermal and combustion efficiencies. To facilitate this investigation, a dedicated test bench is meticulously designed and constructed, equipped with state-of-the-art measuring instruments to effectively monitor the thermal behavior of the heating process. The results reveal that the higher Damköhler number at higher power, driven by the dominance of chemical time over mixing time, accentuates the importance of chemical reactions in heat transfer to the pot. Moreover, increasing the power leads to a reduction in the burner's overall thermal efficiency, from 29.2% to 18.8%, due to a higher energy waste percentage, escalating from 45.12% at P = 12.15 kW to 65.31% at P = 31.04 kW. This increase in power also strengthens the downward movement of the flame and its detachment from the pot surface. The pot's bottom contribution to total heat transfer ranged from 76.7% to 95.5%, with convection alone accounting for over 98% in all cases. Consequently, optimizing the pot bottom geometry for the purpose of enhancing convection presents promising avenues for significantly boosting thermal efficiency. These findings highlight the potential of the investigated porous burner for efficient and clean combustion in cooking appliances.

Characteristics and Efficiency of Heat Transfer for Natural Convection by Ag-CuO/H2O Hybrid Nanofluid Inside a Square Cavity with Corrugated Walls

A parametric numerical study is conducted on laminar natural convection and heat transfer in a cavity with opposing undulated walls saturated with a hybrid Ag-CuO/water nanofluid. The two vertical walls of the sinusoidally undulated cavity are maintained at hot and cold temperatures, while the upper and lower walls are thermally insulated. The investigation examines the effects of relevant parameters such as the sinusoidally undulated geometry of the walls for different volumetric fractions of nanoparticles (0% ≤φ≤6%) and Rayleigh numbers (103 ≤ Ra ≤ 106) Thefinite-volumee discretization method is employed to solve the system of governing equations. The results indicate that an increase in the volumetric fraction of nanoparticles enhances the heat exchange rate in the cavity. Additionally, the Rayleigh number, with a significant increase in surface area, strongly influences the dominant heat transfer mode in the cavity. Furthermore, an increase in the number of wall undulations leads to a reduction in the heat transfer rate.

Analysis of heat transfer modes in the cooling of blocks generating different heat quantities

Achieving improved cooling efficiency and control in electronic components with varying heat outputs can be realized through a thorough analysis of different heat transfer modes, focusing on their contributions and interactions within the system. The analysis is conducted within a cavity containing three circular blocks generating varying amounts of heat. The blocks are affixed to an insulated plate, dividing the cavity into two identical sections with different fluids and different cooling mechanisms. In the open portion of the divided cavity, block cooling is achieved through forced convection using a nanofluid, while the closed section dissipates heat through natural convection and surface radiation. The numerical solution of the governing equations is performed using Galerkin's Finite Element Method, with detailed examination of the cooling process considering various parameters, such as block displacement (1.5cm≤y1≤3.25cm) and dimensions (0.25cm≤R≤1.5cm), Reynolds number (10≤Re≤1000), nanoparticles nature and volumetric fraction(0 %–10 %), emissivity (0≤ε≤1), thermal heat ratio(0.125 to 8), and cavity inclination angle(0°–180°). The results show that the combination of natural convection and surface radiation can be highly effective, rivaling forced convection in cooling the blocks. The study shows that an increase in the Reynolds number results in a temperature reduction of up to 6 °C, while increasing the emissivity leads to a more significant drop of around 10 °C. Additionally, miniaturizing the blocks by reducing their radius by a factor of six causes the maximum temperature to rise by over 20 °C.

Modulation of radiative heat transfer by higher-order topological phonon polaritons

Modulation of radiative heat transfer by higher-order topological phonon polaritons

Numerical Investigation on the Influence of Substrate Board Thermal Conductivity on Electronic Component Temperature Regulation

This study presents a detailed numerical analysis of substrate boards made from various materials (FR-4, Si cladding, and Cu cladding) with nine electronic components mounted on them. Each component is subjected to different heat fluxes, and the analysis covers both natural convection (NC) and forced convection (FC) modes of heat transfer at air velocities of 4m/s and 6m/s. The findings reveal that at an air velocity of 6m/s, using a copper cladding board significantly lowers the temperatures of the electronic components by 340C to 540C compared to FR-4 and Si cladding boards. Additionally, the copper cladding reduces the required air-cooling velocity by 2m/s and achieves a temperature reduction for the IC chips ranging from 3.500C to 13.120C. It is recommended to use an air velocity of 4m/s with copper cladding to minimize fan power consumption while maintaining component temperatures below 1250C. These results provide crucial insights for thermal design engineers, aiding in the selection of appropriate substrate boards for effective thermal management of electronic components. The study emphasizes the benefits of copper cladding in distributing heat more uniformly, reducing energy consumption, and maintaining optimal operating temperatures. Furthermore, it suggests that placing high heat-dissipating components at inlet or outlet points can minimize thermal interactions and overall configuration temperatures. The research offers valuable guidance to the heat transfer community, particularly electronic thermal designers, by highlighting the importance of substrate material choice and component placement in enhancing the reliability and lifespan of integrated circuits (ICs). The comprehensive analysis and recommendations serve as a vital resource for optimizing thermal control strategies in electronic devices, ultimately contributing to improved performance and durability.

Thermal Performance Evaluation of a Single-Mouth Improved Cookstove: Theoretical Approach Compared with Experimental Data

This work aims to address the knowledge gap in the thermal efficiency performance of a locally made cookstove in Mali. Despite the fact that the thermal efficiency of cookstoves is a crucial aspect of cooking, the performance of commercially produced cookstoves in Mali has not been thoroughly studied. In this context, the thermal efficiency of a single-mouth biomass stove has been investigated using a theoretical and experimental approach. First, the fundamental principles of physics for the three forms of heat transfer were applied. Then, the theoretical thermal efficiency of the stove was calculated based on the percentage share of energy gains and losses for the respective heat transfer modes. This analysis shows that the highest energy gain is achieved by radiation heat transfer from the flame and the fuel bed, followed by convection heat transfer to the bottom and sides of the pot, respectively. In order to validate the findings, the theoretical results have been compared with the experimental data at a case study site in Katibougou, Mali. Accordingly, the experimental thermal efficiency is slightly lower than the theoretical value, with a measured value of 27% compared to the theoretical value of 31.45%. The theoretical thermal efficiency can be closer to the experimental efficiency if the combustion losses caused by incomplete combustion of the fuel are taken into account.

Numerical investigation of thermal soak within engine bay using lattice Boltzmann method

A large amount of heat accumulates in the engine bay for a short time after the engine runs at high load and shuts down, that will lead to thermal damage and thermal fatigue caused by the temperature rise of some heat sensitive components. This paper uses an aero-thermal coupling approach to study the heat transfer problem in the engine bay of an SUV model under thermal soak conditions. Due to the transient characteristics of the heat transfer process, the natural transient CFD software developed based on the LBM method is used to study the engine bay heat transfer during the 400 s key-off soak process. The analysis reveals that convection and radiation are the main heat transfer modes in the early stage of hot immersion (0–120 s), and conduction only makes a significant contribution in contact with high temperature sources. The radiation and convection are the key contributors to heat transfer processes of engine bay during soak, but the efficiency of radiation heat transfer decreases with the increase of time, whereas the efficiency of convection heat transfer is not always reduced, it will increase and then decrease with the increase of time. The coupling method established can predict the thermal state in the engine bay well, and is in good agreement with the experimental results. The results show that the error in the engine coolant temperature is less than 1 °C, and the error in the temperature of the heat-sensitive components is less than 5 °C. Finally, the potential risks of thermal damage and thermal fatigue states were assessed, providing an important reference for the control design of cooling fan running time after key-off.

Influence of thermal radiation and magnetic field on convective transfer within an inclined square enclosure filled with Cu-water nanofluid

The present work investigates the effects of thermal radiation and magnetic field on the laminar convective transfer process on copper-based nanofluid within an inclined square enclosure. The studied configuration is a rigid-walled cavity subjected to a horizontal temperature gradient where the left wall is maintained at a hot temperature Th and subjected to a magnetic field B0. In contrast, the right wall is kept at a cold temperature Tc. The horizontal walls are adiabatic. The dimensionless governing equations are solved using the finite difference method and the UPWIND scheme to solve the convective terms. Formulated using the stream function, vorticity, and temperature. Effects on mean Nusselt numbers are investigated at different Rayleigh numbers 104,105,106, Hartmann numbers HA=0to100, tilt angles γ=0,π/6,π/4andπ/3, nanofluid volume fractions 0%≤φ≤6% and different radiation parameters ( Rd=0,1,2,3 ). The findings show that the HTR increased 3.6 times by augmenting the Ra from 104 to 106. Also, increasing the Ha number from 0 to 100 causes an 83.16% reduction in the HTR. Considering the radiation mode of heat transfer causes an increase in HTR. The average Nusselt values increase by 59.72% for the concentration of 6% while increasing the radiation parameter from 0 to 3. On the other hand, an increase in volume fraction leads to a deterioration in mean Nusselt numbers (Numean).

Mathematical modeling and characteristics evaluation of coke replacing with commercial biochar in iron ore sintering process

For green production of iron ore sintering, the research on replacing traditional coke with clean energy such as biochar is a new hot topic. Most of the work conducted in biomass fuel utilization in sintering is done on a laboratory or pilot-scale. Little work was reported by using mathematical models to predict the influence of biomass-based fuel replacement on sintering performance quantitatively. In this paper, a more comprehensive numerical model that incorporates most of the significant reaction processes and heat transfer modes was proposed first, especially with considerations of coke/biochardual-fuelphase heat supply and their pyrolysis, volatiles release, and combustion processes. Experimental data of the sintering pot reasonably agreed with the numerical results, which validated the model. Based on the equivalent fixed carbon method, the combustion and sintering behaviors in replacing proportions, particle size, and fuel types of commercial biochar for coke in the sintering bed were compared. With the lower replacement proportions (<20 %), both two biochars (Oak and Pine) can ensure thermal state indicators (PT, RT, MQI, CR) and combustion performance indicators (FFS and combustion efficiency), and keep the yield enough high. When the replacement proportion exceeds 50 %, the sintering index is worsened significantly. The emission of NOx can be decreased by 57.62 % when a 100 % replacement proportion of biochar is used. The results also indicate that coarsening particle size (2.4 mm was recommended for use) can further improve sintering indicators, and make Oak char 50 % replacing proportion reach the level of all coke method. The performance of pine sintering is even better than Oak sintering. The multiphase multicomponent model is used to give a mechanism explanation for the behavior and performance of biochar replacing coke in the sintering process.

Enhancement and modulation of near-field radiative heat transfer in Bi2Se3/graphene-based three-body configurations

The manipulation of near-field radiative heat transfer (NFRHT) through complex photon tunneling in many-body systems has garnered significant attention, particularly for advancing thermal management in micro- and nanodevices. In this work, we theoretically investigate the enhancement and modulation of NFRHT within a graphene/Bi2Se3-based three-body configuration. Compared to a two-body configuration, the three-body modulator enhances the near-field radiative heat flux (NFRHF) by 2.77, primarily due to the enhancement of surface plasmon polaritons facilitated by graphene. Moreover, we analyze how NFRHF is modulated by varying the vacuum gap between the emitter and the intermediate, adjusting the thickness of Bi2Se3 films in emitter and intermediate, as well as manipulating the chemical potentials of graphene. Results indicate that by tuning the chemical potentials of graphene, thermal regulation can be enhanced up to a ratio of 2.55. This enhancement is attributed to the excitation of SPPs, which are concentrated in a narrower wave vector space and higher angular frequency range as the chemical potential of graphene increases. These findings have implications for controlling thermal radiation applications utilizing graphene and Bi2Se3 heterostructures. This work demonstrates the superiority of the three-body system in enhancing NFRHT and contributes new insights into the potential applications of Bi2Se3 in NFRHT.

Analysis of vapor bubble diameter, departure frequency and dynamics in a single cavity

The ongoing quest for methods that enhance the efficiency of heat transfer processes, particularly those involving phase change, underscores the importance of comprehending the dynamics of vapor bubbles during boiling. This study investigates heat transfer mechanisms and the dynamics of vapor bubbles within the nucleate boiling regime. Experimental tests were conducted on a flat copper surface featuring a single cavity, focusing on analyzing vapor bubble growth and departure stages. The working fluid examined was HFE-7100 under saturated conditions. The formation and growth aspects of vapor bubbles, including their diameter (Dd) and departure frequency (f), were investigated through experimental data obtained by two different techniques: by an optical sensor of variable resistance capable of generating an analog signal from a voltage change and by a high-speed camera that captures images immediately after the instant that the bubble detached from the surface. Both techniques provide visual insights into the boiling phenomenon. An escalation in heat flux and, consequently, wall superheat resulted in an increased bubble departure frequency. Furthermore, the optical flow analysis successfully identified velocity and vorticity fields induced by micro convection, the prevailing heat transfer mode in nucleated boiling. A slight horizontal displacement trend over time was observed, which may be caused by the asymmetry in the velocity profile, confirmed by velocity peaks tending toward one direction. Vortex analysis reveals rotational motion concentrated in specific regions, with noticeable deformation near the bottom of the bubble and asymmetric movement contributing to vorticity. These findings provide insights into the vapor bubble dynamics, which is important for understanding the cavity rewetting phenomena.

Development of novel thermal diode inspired by the structure of venous valve

To increase the unidirectional heat transfer capability of a thermal diode, a novel thermal diode with unidirectional movable valves as vapor channel is proposed based on the structure of venous valves. The thermal performance of this bionic thermal diode was experimentally investigated under different working conditions. The results demonstrate that the bionic thermal diode exhibits a high thermal rectification ratio and strong stability. The best thermal rectification ratio is 10.79, with a forward thermal resistance of 0.26 °C/W and a reverse thermal resistance of 2.86 °C/W, at a heating power of 15 W and a filling ratio of 15 %. The temperature distribution indicated that, under the reverse heat transfer mode, the vapor was obstructed at the first valve, leading to the high thermal resistance of thermal diode. Additionally, the effect of inclined angle on the thermal performance of thermal diode was also investigated. This study provides a novel approach for the design of thermal diodes.

Natural convection heat transfer in an eccentric annulus filled with hybrid nanofluid under the influence of thermal radiation and heat generation/absorption

This investigation aims to scrutinize the flow and heat transfer characteristics of a hybrid nanofluid composed of Ag-MgO within an eccentric annular space, where the inner circular wall is held at a constant elevated temperature and the outer circular wall is uniformly cooled. Natural convection in such eccentric annular enclosures, with thermal radiation and the effects of heat generation/absorption taken into consideration, plays a vital role in various engineering applications, including solar collectors, nuclear reactors, thermal storage systems, and heat exchangers. The resolution of the fundamental governing equations was executed employing the Gauss-Seidel approach, with the inclusion of a sub-relaxation process, all within the framework of the finite volume method. The impact of the Rayleigh number, radiation number, volume fraction as well as heat generation/absorption coefficient on thermal transfer, flow, and temperature distributions were investigated. It was observed that for low Rayleigh numbers, radiation influences enhance flow stability and improve the conductive heat transfer mode. Conversely, at high Rayleigh numbers, radiation intensifies convective heat exchange. The growth of the Rayleigh number diminishes the impact of heat generation and reinforces the radiation heat transfer process, while heat absorption exhibits the opposite effect. From Nr = 1 onwards, the average Nusselt number values are no longer influenced by an increase in nanoparticle volumetric fraction, and they are solely linked to the radiation number.

Discussing the limitations of unconditional stability indicators in evaluating thermoacoustic quality of burners with flames

Assessing the thermoacoustic performance of designed combustors, with a focus on the stability quality factor, is crucial. Thermoacoustic instability in combustion appliances arises from intricate interactions among unsteady combustion, heat transfer, and (maybe) acoustic modes within the system. Accurate prediction of system stability requires modeling all components, including the burner with flame. Traditionally, the burner in the presence of combustion is represented as an acoustically (active) two-port block with passive upstream and downstream acoustic terminations. The dispersion relation of the thermoacoustic system is commonly used for anticipating eigen-frequencies and assessing stability. However, practical scenarios often lack specific information about upstream and downstream terminations during development. This raises a critical question: How can the thermoacoustic performance of burners and their associated flames be evaluated without specified acoustics? This article addresses this question by exploring the concept of unconditional stability in a generic two-port thermoacoustic system. The unconditional stability criteria have been used as quality indicators in designing electrical devices. This rich toolbox has been introduced in thermoacoustics. We first scrutinize assumptions underlying two most known unconditional stability-based criteria called [Formula: see text] and [Formula: see text] factors, connecting them to the general thermoacoustic problems. Then, the application of these criteria in assessing the thermoacoustic quality of burners with flames are discussed. This investigation revealed that while they are able to accurately predict the histogram of unstable frequencies and critical frequency bands, their use as reliable indicators to assess thermoacoustic quality in burners are not recommended due to their mathematical limitations and high level of conservatism of these factors.

Influencing heat transfer and drag in magneto-hydrodynamic non-Newtonian fluids with polymer additives: A novel theoretical approach

This article examines the impact of polymers on boundary layer flow and heat transfer in non-Newtonian fluids over a magnetized stretching surface. Using the Oldroyd-B model, Reiner-Philippoff fluid stress deformation, and Maxwell’s equations, the study explores polymer behavior in a magnetic field. Similarity transformations are applied to derive the governing equations, which are solved numerically. The effects of polymers and magnetic fields on drag and heat transfer are illustrated graphically. The analysis highlights that introducing polymers increases skin drag and the Nusselt number while reducing the magnetic flux coefficient. Higher polymer concentrations enhance drag and heat transfer. The magnetic field significantly improves heat transfer and reduces skin drag. The research offers valuable insights into the optimal use of polymer additives to modify heat transfer and drag in non-Newtonian fluid flow, contributing to advancements in fluid dynamics and thermal management technologies.

The role of cavity shapes in improving the performance of a heat sink incorporating nano-enhanced phase change material

Improving the cooling performance of heat sink is critical for providing better thermal management to compact electronic devices. Thus, analyzing various cavity shapes for a heat sink containing Nano-enhanced Phase Change Material is of utmost necessity. The present study focuses on a two-dimensional conjugate heat propagation in a Heat sink with Rectangular (HRC), Trapezoidal (HTC), and Wavy (HWC) cavities. Various cavity shapes are examined to identify the ideal shape for a heat sink containing nano-enhanced Phase Change Material (Ne-PCM). The copper oxide (CuO) nanoparticle enhanced paraffin is considered as Ne-PCM. The analysis encompasses identification of the potent cavity shape, its optimum geometric parameters, the dominant mode of heat transfer and ultimately the desirable thermophysical properties of the Ne-PCM. Among HRC, HTC, and HWC, the heat sink with HRC performs the best by maintaining the lowest base temperature. The HTC, has a better initial performance than the HRC, though HTC has low PCM content. Nevertheless, as time progresses, HTC fails to inhibit the base temperature rise. In contrast, due to increased contact surface area, PCM in HWC experiences a stronger opposing viscous force. Consequently, HWC has conduction-dominated heat transfer and the slowest melting of PCM that elevates the base temperature, accumulating heat near cavity walls. Shortening the relative pitch distance and elongating the relative height of the HRC further lowers the base temperature of the heat sink. Notably, the heat transfer mode analysis reveals that in the cavity with maximum height, heat diffusion dominates convective heat transfer. Heat diffusion increases away from the cavity walls towards the middle of the cavity. Ultimately, it is noted that a denser PCM with high thermal conductivity and low viscosity effectively maintains a low heat sink base temperature. A denser PCM imparts more sensible and latent heat absorption capability and maintains a lower base temperature. On complete melting, the convective heat transfer is much higher in a denser PCM. A PCM with higher thermal conductivity marginally lowers the base temperature with a small increase in PCM melting rate.