Solid Fin Research Articles

A numerical investigation on the effect of shape-size-number of drills on heat transfer characteristics of a circular pin fin

An increased circuit density with digitalization and miniaturization demands a compact design for the heatsink with enhanced heat dissipation capabilities. The performance of an active air-cooled pin fin heatsink depends on the geometry of the fin, which should offer more surface area for the given volume (Compact). Providing drills in a pin fin offers a more convective surface with conduction loss, and is function of place, size, shape, and number of drills. So, this investigation is focused on studying the heat transfer characteristics of a drilled pin fin of length L and diameter D to elucidate the effect of (1) shapes; circular, elliptical, and triangular, (2) locations; L/4, L/2, and 3 L/4, (3) sizes between 0.3D and 0.5D, and (4) number; 1, 2, 4, and 6 of drills on maximum fin temperature (Tmax ) and convective resistance for differential heat inputs in different convection environments. It throws light on the possible replacement of solid fins with drilled fins for enhanced heat dissipation. It offers either more heat transfer, for the given volume with reduced weight, or decreased volume for the mandated heat load. The results demonstrated that the drill location has a mere or insignificant effect on Tmax. For all the shapes considered in the study, Tmax first decreases with the enlarging drill size reaches it’s minimum at 0.5D, and increases after that. The increased number of drills from 1 to 6, of size 0.5D, brings down the Tmax by 20%, 20%, and 25% with circular, elliptical, and triangular drills, respectively.

Experimental study of an aluminum based three-dimensional thermosyphon heat sink with microscale enhancement structure

One of the most significant limitations to the advancement of electronics is the issue of heat dissipation. Currently, air cooling remains the most widely used method for heat dissipation due to the advantages of low cost and ease of maintenance. However, the traditional air-cooling method based on an all-solid heat sink is unable to keep pace with the rapid advancement in thermal power of electronics due to its limitation in area expansion by only solid fins. This study proposes an aluminum-based three-dimensional thermosyphon (3D-TS) coupling boiling-condensation heat transfer and forced air cooling as a means of overcoming the limitations of conventional air-cooling methods. Additionally, the incorporation of micro pin-fins enhances the boiling heat transfer and the overall performance of the three-dimensional thermosyphon. The performance of the three-dimensional thermosyphon is experimentally studied and analyzed under different volumetric flow rates using the environmentally friendly refrigerant R1233zd(E) as the working fluid. The results indicate that the total thermal resistance exhibits a biphasic response to heating power, with a decrease initially followed by an increase. This response is primarily attributed to the boiling mode on the substrate. Moreover, the micro pin-fins significantly enhance the boiling heat transfer on the substrate of the three-dimensional thermosyphon, enabling the three-dimensional thermosyphon to reach a minimum thermal resistance of 0.075 K/W and a maximum thermal dissipating power of 650 W with the temperature of the heating source below 85 °C. The three-dimensional thermosyphon proposed in this work is capable of meeting the cooling requirements of the majority of high-performance chips. This paper offers a valuable reference and guidance for the design and optimization of the phase-change devices.

Numerical simulation of natural convection in a differentially heated cubical cavity with solid fins

PurposeThe performance of solid fins inside a differentially heated cubical cavity is numerically studied in this paper. The main purpose of the study is to make an optimization to reach the maximum heat transfer in the enclosure having the solid fins with studied parameters.Design/methodology/approachThe considered domain of interest is a differentially heated cube having heat-conducting solid fins placed on the heated wall while an opposite wall is a cooled one. Other walls are adiabatic. Governing equations describing natural convection in the fluid filled cube and heat conduction in solid fins have been written using non-dimensional variables such velocity and vorticity taking into account the Boussinesq approximation for the buoyancy force and ideal solid/fluid interfaces between solid fins and fluid. The formulated equations with appropriate initial and boundary conditions have been solved by the finite difference method of the second of accuracy. The developed in-house computational code has been validated using the mesh sensitivity analysis and numerical data of other authors. Analysis has been performed in a wide range of key parameters such as Rayleigh number (Ra = 104–106), non-dimensional fins length (l = 0.2–0.8), non-dimensional location of fins (d = 0.2–0.6) and number of fins (n = 1–3).FindingsFrom numerical methods point of view the used non-primitive variables allows to perform numerical simulation of convective heat transfer in three-dimensional (3D) regions with two advantages, namely, excluding difficulties that can be found using vector potential functions and reducing the computational time compared to primitive variables and SIMPLE-like algorithms. From a physical point of view, it has been shown that using solid fins can intensify the heat transfer performance compared to cavities without any fins. Fins located close to the bottom wall of the cavity have a better heat transfer rate than those placed close to the upper cavity surface. At high Rayleigh numbers, increasing the fins length beyond 0.6 leads to a reduction of the average Nusselt number, and one solid fin can be used to intensify the heat transfer.Originality/valueThe present numerical study is based on hybrid approach for numerical analysis of convective heat transfer using velocity and vorticity that has some mentioned advantages. Obtained results allow intensifying the heat transfer using solid fins in 3D chambers with appropriate location and length.

Numerical simulation of thermal performance of heat sink augmented with phase change material PCM integrated with solid and aluminum metal foam fins

AbstractThis study introduced a novel numerical modeling for the evaluation of a hybrid heat sink design by replacing the solid fins with aluminum foam fins (AFF) for the same thickness of 2 mm within a phase change material (PCM). This innovation is designed to enhance thermal performance in electronic cooling applications. Heat fluxes of 2, 3, and 4 kW/m2 were applied to the base. The performance has been verified at set point temperatures (SPT) of 60°C, 70°C, and 80°C, encompassing a range relevant to various applications. Different AFF thicknesses (4 and 6 mm) and foam porosities (0.85, 0.90, and 0.95) were investigated. The study demonstrated that AFFs improve heat transfer by increasing fin surface area and by effectively raising the thermal conductivity of the PCM. Compared to the SF heat sink, the results show that the AFF design extended the operational time by 5%–8% for the range of heat fluxes. Notably, AFFs with a thickness of 6 mm achieved a significant 41% improvement in the operation time at a lower SPT (60°C). The metal foam porosity of ε = 0.85 exhibited superior thermal performance within the investigated temperature range. This research paves the way for optimizing hybrid heat sink designs using metal foam for efficient thermal management and reduction of weight.

Numerical simulation of various PCM container configurations for solar dryer application

In the context of solar dryers, where drying time is constrained by available sunshine hours and excessive heat during these periods can potentially lead to mineral loss in food, the incorporation of phase change material (PCM) for thermal energy storage emerges as a viable solution. However, the response time of PCMs plays a major role in its charging and discharging in solar dryer performance, prompting extensive research into PCM container configurations to reduce this limitation. Investigations have been conducted through numerical simulations and experimental studies to explore various configurations of PCM. In this study, four distinct container configurations were employed, alongside the introduction of fins, with two variations: solid and hollow. In this regard, Paraffin RT58, with its melting point closely aligned with the operating temperature of the solar dryer, is considered a suitable choice in simulation using ANSYS Fluent. The simulation results revealed that the horizontal rectangles demonstrate the quickest rates for melting and solidification, whereas the cylindrical shape exhibits the most extended durations for these processes. The introduction of fins has a notable impact on reducing both melting and solidification times, with a further decrease observed as the number of fins increases. While solid fins provide slightly superior reductions in melting and solidification times, opting for hollow fins presents benefits in terms of material efficiency, weight reduction, and cost savings.

Effect of PCM-filled hallow fin heat sink for cooling of electronic components — a numerical approach for thermal management perspective

This paper aims at the PCM-based heat sink for electronic cooling. In the present analysis, paraffin wax-based phase change material (PCM), in 3-fin and 4-fin hollow heat sinks with the proper volume of PCM in the temperature of the electronic components can be controlled. The PCM-filled heat sinks are placed on top of the high heat-generating integrated circuit (IC) components. The aim is to reduce the maximum temperature of the electronic components and keep them below their critical temperature, hence increasing the life of the IC chips. A correlation is put forward for dimensionless temperature ([Formula: see text]) in terms of heat flux ([Formula: see text]), volume content ([Formula: see text]) and size of the IC chips ([Formula: see text]). It has been found that there will be a 4–[Formula: see text]C drop in temperature when compared to solid fins heat sinks. It is confirmed that the temperature of the IC chip is a strong function of heat flux, size and volume content of PCM.

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.

Exact theoretical solution and numerical study of thermal analysis of a type of nonlinear temperature-dependent material fin

As an essential part of many structures in engineering applications, the influence of fin is necessary. For this reason, studies on temperature fields and thermal properties of fin are essential. In the paper, based on the nonlinear temperature-dependent material, exact solutions for temperature distribution, heat transfer rate, efficiency, and effectiveness of fin are obtained by comprehensively considering different thermal influence parameters. In addition, a three-dimensional solid fin model is established by ABAQUS software, and the secondary development of the HETVAL subroutine is carried out with the help of the FORTRAN language. The numerical simulation results, in some cases, are intuitively shown and compared with the theoretical results. This study provides a comprehensive theoretical basis for future experimental studies, numerical simulation analysis, and engineering practice of fins with different materials.

Novel approach to cooling microelectronics with complex fins configuration

This paper presents a numerical simulation and optimisation of a complex microchannel featuring innovative fin designs. The primary objective of the study is to minimise resistance in the heat sink by utilizing intricate fin structures. Three different approaches are explored: firstly, cylindrical solid fins are designed and placed on the heat sink; secondly, the solid fins are drilled halfway (50 %); and in the third scenario, the solid fins are drilled 87.5 % and mounted on the heat sink. In the simulation set-up, the heat sink has a heat load of 250 W imposed on the bottom wall and single-phase water of Reynolds number between 400 and 500 flows in a forced convection laminar condition to remove the heat at the bottom and internally within the fins walls surface area, while an air stream of Reynolds number between 3 and 6 flows convectively across the cylindrical fins to dissipate excess heat externally. The finite volume method and computational fluid dynamic code, are employed to discretise the geometry with heat and fluid fields solved. The optimisation is performed for parallel and counter flows and the outcomes compete favorably. Similarly, the influence of the Reynolds number on minimised temperature and resistance results is discussed. The results show that in parallel flow the integrated heat sink with half hollow fins is best with a minimised resistance of 27.2 %, while in the counter flow the hollow fins are superior with a declined resistance of 19 %. The study is validated with experimental results in open literature.

Effect of Porous Fin Property on Thermohydraulic Performance of Porous‐Fin Microchannels at Different Geometric Configurations

The utilization of porous‐fin microchannel (PFM) heat sinks has become prevalent for the cooling of microelectronic chips. This paper employs three‐dimensional simulation to examine the potential benefits of substituting a solid fin with a porous fin for enhancing the thermohydraulic performance. The influence of porous structure features on the thermal and hydraulic behavior of the PFMs at different geometrical configurations is investigated. Results show that in all configurations, employing a porous fin reduces the pressure drop. The heat transfer in PFMs is influenced by the convection in the main fluid path as well as convection in the porous fin structure. An increase in the permeability of the porous fins results in enhanced overall heat transfer due to the augmented convection within the fins. On the contrary, an increase in fin porosity leads to a heat transfer reduction as the effective thermal conductivity of the fin is diminished. The possibility of enhancing thermal performance via the substitution of the solid fin with a porous fin is diminished as the height of the microchannel increases. This is attributed to the weak vertical thermal diffusion of the porous material. Moreover, the findings indicate that the geometric configuration of microchannels has an essential role in heat transfer performance of the porous fin. For instance, the thermal resistance of the PFM with a height ratio of 1.5, porosity of 0.85, and permeability of K = 5 × 10−8m2 is 10.4% less than that of the solid‐fin microchannel (SFM). However, by decreasing the permeability to K = 5 × 10−10m2, the thermal resistance of PFM was 26% higher than that of the SFM.

Numerical study on the effect of optimizing the Trombe wall structure with built-in fins on improving building energy efficiency in severe cold region

In order to save heating energy and reduce carbon emission intensity, a floor heating room with built-in finned Trombe wall in Xining, Qinghai, a severe cold area, was taken as the research object. And ANSYS 2021 R1 was used to numerically investigate the effects of several major factors, such as fin height, fin transverse distance, fin longitudinal distance, fin inclined angle, fin shape, perforated shape and perforation ratio of perforated fin, on the average heat transfer coefficient (h) between the absorptive surface and the air in the interlayer. The results show that for fins with low heights, the enhancement effect of horizontal fins on the convective heat transfer of the absorptive surface of Trombe wall is greater than that of vertical fins. The enhancement effect of vertical fins on the convective heat transfer of the absorptive surface is more affected by fin transverse distance, while the enhancement effect of horizontal fins on the convective heat transfer of the absorptive surface is more affected by fin longitudinal distance. Besides, h shows a trend of first increasing and then decreasing with the increase of fin inclined angle, and reaches its maximum value of 5.89 W/(m2·K) at 45°. The fins with different shapes are equilateral triangular fins, semicircular fins, isosceles triangular fins and rectangular fins in descending order of their enhancement effect on the heat transfer of wall. Compared with solid fins, fins with circular holes can obtain a better convective heat transfer effect only when the open area ratio is 1:6. While fins with equilateral triangular holes can obtain better convective heat transfer effect as long as the open area ratio is greater than 1:7. Fins with elliptical holes do not significantly improve the heat transfer effect. On the basis of optimizing the fin layout and structure, the thermal performance of the improved Trombe wall during the 8:00∼16:00 period and its impact on indoor thermal comfort of the building were studied, and the energy-saving performance of the plan was discussed. Compared with the Trombe wall room with no fins, the improved Trombe wall can improve the heat teransfer efficiency and the building energy saving rate by 68.50 % and 53.57 %, respectively. The improved Trombe wall can only ensure the indoor thermal comfort in limited several hours, in the rest of time, the residents should add clothing to keep warm. These conclusions have an important effect of engineering guidance and great realistic meanings for promoting the process of solar building integration and achieving the “carbon peak and carbon neutrality” target.

Heat transfer enhancement using combined microchannel with vertical rectangular micro fins

This paper focuses on the numerical optimisation of a combined hybrid microchannel heat sink with rectangular solid fins. The axial length and volume are fixed, and external structure is allowed to vary. The simulation was performed on an elemental unit cell of the microchannel heat sink . The purpose of the optimisation is to discover an optimal geometric arrangement in internal and external configurations that minimises peak temperature in the microchannel heat sink. A high-density uniform heat flux of 250 W/cm2 is assumed to be dissipated on the bottom wall of the unit cell by microelectronics circuit boards devices. Computational fluid dynamic code was used to discretized the fluid domain and solve a set of governing equations. The influence of hydraulic diameter, external structural shape and fluid velocity on peak temperature and global thermal resistance, is discussed. Coolant or water of Reynolds number range 400 to 500 in a forced convection laminar flow is introduced through the inlet of the computational domain to remove the heat at the bottom of the rectangular block microchannel. The results show that when the fluid velocity is increased from 9.8 to 12.3 m/s across the axial length of the micro heat sink, more heat is removed from the bottom of the combined heat sink. The results revealed that the pump power increased by 37.1% in combined microchannels with fins and from by 27.2% in finless micro heat sink. The result of the study is validated with what is documented in open literature for a traditional micro heat sink with circular flow channel and the trends agree.

A novel integrated flat thermosyphon heat sink for energy-efficient chip-level thermal management in data centers

A novel Integrated Flat Thermosyphon Heat Sink (IFTHS) with enhanced performance is developed in the present study. The IFTHS has a condenser with integrated hollow fins wherein the inner surface of the hollow fins is used for condensation, and the outer surface is used for air-side convective cooling. The thermal performance of the IFTHS is investigated at different filling ratios to find the best-performing filling ratio. The thermal performance of the IFTHS is improved further through an evaporator with minichannels and superhydrophobic condenser. Superhydrophobic condenser improved the performance by 16 % due to quicker condensate return and dropwise condensation. Minichannel evaporator improved the performance by 19 % due to enhanced pool boiling from improved bubble dynamics and increased surface area. The combination of a superhydrophobic condenser and minichannel evaporator improved the performance by 36 %. The overall resistance, maximum temperature, and heat sink weight are reduced by 19–41 %, 8–25 °C, and 44–46 % with IFTHS configurations compared to the baseline conventional flat thermosyphon having a condenser with solid fins. The electronic component lifespan can be increased by 3.73–17.75 times, and the room air cooling load can be reduced by 8.04–25.12 kJ/kg when the IFTHS configurations are used for cooling electronic chips in data center servers instead of the baseline configuration. Thus, the novel IFTHS configurations developed in the present study can contribute to energy-efficient chip-level thermal management in energy-intensive data centers.

Heat transfer enhancement of phase change materials PCMs using innovative fractal H-shaped fin configurations

Despite their limited thermal conductivity, phase change materials (PCMs) have been extensively utilized in numerous engineering applications as a means of energy storage. Using the biomimicry method, an innovative configuration was proposed and investigated numerically. It was inspired by trees' structures aiming to improve the melting performance of triplex concentric tube heat exchangers.Based on the Computational Fluid Dynamics (CFD) code, this study examines the impact of integrating innovative fractal H-shaped solid fins, as well as various geometrical parameters such as the number of patterned fins, arrangement type, and stretched fins, on enhancing the PCM's performance. Compared with previous experimental work, the numerical method was validated.Through two-dimensional 2D simulations, the main objective of this work was to identify the optimal configuration that effectively maximizes the heat transfer performance during the charging process and significantly enhances the overall efficiency of an energy storage system filled with RT82.The obtained results demonstrate the positive impact of applying the bio-inspired fractal H structures to enhance the melting process. The configuration with four fin patterns achieved an improvement of 69.14 % compared with the thermal energy storage TES system equipped with uniform plate fins.

Experimental investigation of heat transfer enhancement by using perforated fin array having different perforation ratios, angle of inclination and configuration of fins under forced convection condition

In this research work experimental investigation and comparative study of heat transfer enhancement between solid fins and circular perforated fin array is performed. Current investigation is mainly associated with inline and zigzag configuration of perforations, angle of inclination (0○-90○) and size of perforation (4-12 mm) under forced convection condition. Enhancement of performance is reported at 10 mm diameter size perforation (perforation ratio, β = 21%) and 45○ angle of inclination. Among the fin arrays used in this study two rows of zigzag perforation (ZC) is found to be superior than two rows of inline perforations (IC) configurations. The highest ratio of Nusselt number of perforated fins to that of solid fins up to 1.73 fold is reported. As against solid fin array 57.27% heat transfer enhancement with 21% saving in fin material is reported. Based on optimized experimental results mathematical correlation is suggested for the range of parameters viz. Reynolds number (14,783 ≤ Re ≤ 73,916), angle of inclination (θ = 45○), perforation ratio (0 ≤ β ≤ 0.21) and heat input (Q = 60 W).

Computational thermal analysis of a latent heat storage unit augmented with porous fins

Phase change material (PCM)-based thermal energy storage systems provide a large capacity to store energy; however, PCMs are impaired by relatively low thermal conductivity. Presently, the use of copper foam annular fins was numerically investigated in a PCM-based thermal storage unit. Six copper annular fin cases were studied: three cases with 10 fins and three cases with 20 fins. The 10 and 20 fin cases included configurations with solid fins and two porous fin cases including 40 PPI with porosities of 90.91% and 97.20%. Simulations were completed in ANSYS-Fluent to examine the effects of porous annular fins on the charging and discharging cycles of a vertical shell-tube unit with Rubitherm RT-55 PCM. The cases were compared based on required time to completely melt and solidify the PCM, along with the energy response of the system. Charging times for the solid, 90.91% porous, and 97.20% porous 10 fin cases were 11.89, 19.92, and 23.33 h. The same cases discharged the system in 11.39, 19.50, and 27.28 h. Equal cases with 20 annular fins charged the system in 10.00, 22.78, and 28.08 h, and discharged in 9.08, 18.14, and 26.22 h. Increased convection from porosity cannot overcome reduction of effective thermal conductivity.

Comparative study of performance enhancement of latent thermal energy storage system with copper porous fin

Phase change material (PCM)-based thermal energy storage (TES) has attained significant attraction towards energy savings and ensures a continuous energy supply. However, the lower thermal conductivity of PCM impedes the efficient transfer in the storage systems, thereby causing longer charging time. Therefore, this paper introduces a novel heat transfer augmentation technique by incorporating copper porous fins in the shell-tube latent heat thermal energy storage. Further, to demonstrate the contribution of porous fins in heat transfer improvement, full-foam, solid-fin and without-fin TES systems are also evaluated and compared. A two-dimensional axisymmetric numerical model is developed and validated with in-house experimental results. It is found that conduction strongly affects the solidification process, exhibiting a greater response rate than the melting process of heat transfer enhancement techniques. Full-foam has higher melting and solidification rates, followed by solid-fin, porous-fin and without-fin. Compared to the without-fin configuration, the temperature response rates of the full-foam, solid-fin and porous-fin are improved by 169.9 %, 44.8 % and 41.88 %, respectively, during the melting process. Moreover, it is revealed that the porosity of foam has a marginally higher impact on the liquid fraction than the pore density. Further, the inclusion of porous-fin and full-foam leads to more uniform temperature distribution in PCM during melting and solidification compared to solid fin and without-fin. Therefore, the porous-fin and full-foam may be utilised for electronic cooling and battery thermal management, which requires uniform cooling at faster rates.

Numerical Simulation of Conjugate Mixed Convection in 3D Channel with Heat-Generating Flat Element and Symmetrical Solid Two-Fin System

This paper presents the numerical simulation results of conjugate mixed convection in a three-dimensional channel with a heat-generating element and solid fins. It should be noted that the symmetrical location of fins has been studied. The system of partial differential equations, presented in dimensionless form using velocity and vorticity vectors, has been solved by the finite difference method on a uniform grid. The central difference schemes have been used to approximate diffusive terms. In contrast, for an approximation of convective terms, the monotonic Samarskii difference schemes have been applied to improve the stable properties of central differences of the second order of accuracy. Analysis has been performed on a wide range of governing parameters, including the Reynolds number (200 ≤ Re ≤ 1000), the material of the fins (aluminum, copper, and iron), and the location of the fins on the heater surface, taking into account the identical distances between the fins and the nearest walls. Water has been considered a working cooling medium. The obtained outcomes characterize the most efficient heat removal from the surface of the energy source using the considered fin system. For example, by using copper fins, the cooling efficiency of the heating element can be increased. The average heater temperature decreases significantly with an increase in the Reynolds number. The distance between the fins also makes a significant contribution to the cooling phenomenon. It is noted that with the most successful choice of location, it is possible to decrease the temperature of the heater by more than 12%.

Heat Transfer and Performance Enhancement of Porous Split Elliptical Fins

To augment the heat transfer phenomenon, the infusion of various fin geometry over the heated plate is being investigated by various researchers. Solid fins of the porous medium can enhance the convective heat transfer, providing a higher surface area-to-volume ratio for heat transfer. In this work, the fluid flow pattern and thermodynamic analysis of porous-based split elliptical fins mounted staggered over a heated base plate is numerically studied with the Reynolds numbers in the range of 783 to 1839, which is dependent on the fin dimension. The variable parameters were dimensionless transverse offset ( TO ∗ = transverse offset / diameter ), which varied from 0 to 0.5; dimensionless longitudinal offset ( L O ∗ = longitudinal offset / diameter ), which varied from 0 to 0.25; porosity (ɸ), which varies from 0.8 to 0.92; pores per inch (PPI), which was 10; permeability ( P n ); and inertial parameter ( F ). To count the viscous and inertial effect inside the porous zone, the Forchheimer–Brinkman extended Darcy model was adopted. The associated parameters, the Nusselt number (Nu), frictional coefficient ( C f ), and performance evaluation criteria (PEC), are thoroughly analyzed over the TO ∗ and LO ∗ combination. The results of the investigation revealed that the highest value of Nu and PEC was obtained by TO ∗ = 0.5 and L O ∗ = 0 at ɸ = 0.92 , which were approximately 54% and 79% higher than the solid circular fin at Re = 1839 . Additionally, a response function based on Nu was obtained using the response surface method, and cuckoo optimization was assessed to identify the optimal Nu. The optimal Nu is established at TO ∗ = 0.4141 and L O ∗ = 0 ( ɸ = 0.92 and Re = 1839 ) and was validated with the present investigation with an accuracy of 1.20%.

Transient thermal management characteristics of a porous fin with radially outwards fluid flow

Thermal management and energy storage problems often utilize extended surfaces, also known as fins for enhanced heat transfer. While thermal conduction is usually the dominant mode of heat transfer in a solid fin, the use of porous fins that include advective thermal transport due to porous fluid flow has also been investigated. In particular, the steady state thermal performance of a porous fin with pressure-driven radially outwards flow has been studied. While such results are helpful for studying problems that are inherently steady state in nature, such results do not readily apply to problems where heat removal or energy storage occurs only over a short period of time. This work presents transient thermal analysis of a porous fin with radial porous fluid flow driven by a pressure gradient. It is shown that the transient temperature field in the fin is governed by a transient convection-diffusion-reaction (CDR) equation, the solution for which is derived in the form of Bessel functions. Based on this solution, the evolution of fin performance with time is examined. Comparison of heat removed by the porous fin with a baseline case without any fin is carried out. The time taken to reach steady state is calculated. Key non-dimensional parameters appearing in this problem are identified and their impact on fin performance over time is investigated. Since fin porosity improves advective thermal transport but suppresses diffusive transport at different rates at different times, therefore, it is shown that for a given operating time, there may exist an optimal porosity that maximizes the rate of heat removal. It is shown that the operating time period of the fin plays a key role in determining whether fin porosity strongly impacts heat removal rate or not. Consequently, it is shown that it is important to consider transient effects in determining whether the use of a porous fin is beneficial at all, and, if so, what is the optimal fin porosity to use. This work contributes towards porous fin theory, and offers practical design guidelines for improving and optimizing the transient performance of porous fins.