Heat Sink Design Research Articles

Experimentally and Numerical Optimization of the Heating Transfer Performance of a Heatsink using Various Fins Shapes

Effectively dispersing thermal energy from mechanical and electrical components is essential for heatsinks, especially in the rapidly evolving electronics industry. The need for enhanced power efficiency and reduced dimensions has underscored the importance of creating heatsink designs that are both effective and able to maintain performance without necessitating enlargement. A diverse array of studies about heat transfer through convection in finning applications exist. This study used experimental and numerical methods to examine forced convection heat transfer utilizing various fin geometries at air velocities of 2.5, 3, 3.5, 4, 4.5, and 5 m/s. The three configurations of fins are folded, corrugated, and flat plate fins. These fins are meticulously constructed from aluminium for all three configurations. The wind tunnel utilized in this study is constructed with a rectangular cross-section measuring 150x60 cm and a length of 2 m; it is evaluated throughout a range of Reynolds numbers from 21,000 to 45,000. The heat sink's average temperature and fin efficiency are computed for various fin geometries for three distinct heat flux values (80, 100, and 120 W/m²), along with the heat transfer rates. The fins are positioned centrally inside the stream, and the thermal heater is affixed to them; power suppliers furnish the heater and fan. The experimental findings exhibited the overall heat transfer coefficient and efficacy. According to the results, heatsinks with folded fins are deemed superior in shape compared to flat plates and corrugated designs.

Thermoelectric Energy Harvesting for Exhaust Waste Heat Recovery: A System Design.

Thermal energy harvesting for high-speed moving objects is particularly promising in providing an efficient and sustainable energy source to enhance operational capabilities and endurance. Thermoelectric (TE) technology, by exploiting temperature gradients between a heat source and ambient temperature, can provide a continuous power supply to such systems, reducing the reliance on conventional batteries and extending operation times. However, the integrated thermoelectric generator (TEG) system design research is far behind materials development. In this study, both experimental and numerical studies of TEG systems are designed and conducted to recover thermal energy. An integrated proof-of-concept platform is developed to simulate an exhaust gas emission system and demonstrate the designed TEG system performance. Triangular plate-fin heat exchangers are designed to collect heat from exhaust pipelines such as engine exhaust gas. While longitudinal trapezoidal fin cylindrical heatsink is designed for dissipating heat via forced convection, particularly for high-speed moving objects, the heatsink design is optimized using finite element analysis (FEA) simulations to maximize the temperature gradient and electrical output power. As a result, under a temperature gradient (ΔT) of 190 °C with commercial bismuth telluride-based TE modules, a maximum system output power of 40 W is achieved experimentally. Furthermore, a computational simulation is conducted to showcase the feasibility of the current system design under high-speed moving vehicle conditions. This study provides an advanced TEG system design bridging the TE device and integrated system transition and represents a potential advancement in the pursuit of high-speed moving objects such as autonomous and longer-lasting aerial platforms.

Optimizing Minichannel Heat Sink Design: A Combined Numerical and Experimental Analysis of Inlet/Outlet Configurations and Pin Fin Enhancements

ABSTRACTThe present study investigated the effect of inlet location, counterflow and parallel flow configurations, and rib addition (pin fins) on the performance factor of minichannel heat sinks. Different rib spacings were investigated in Models D, E, and F, which are 5, 7, and 9 mm, respectively, all using counterflow. These models used ribs with a diameter of 1 mm. In addition, Models G and H were presented to explore different rib sizes (1.5 and 2 mm) while maintaining a rib spacing of 5 mm under counterflow conditions. All effects were studied numerically using ANSYS Fluent 19R3 under laminar coolant flow, with Reynolds numbers ranging from 1190 to 1900. The study also included fabricating two models: the conventional model and the optimized model, and comparing their results with the numerical results. The comparison indicated a satisfactory convergence between the experimental and numerical results. The results revealed that all modifications significantly improved the temperature distribution and overall performance factor (OPF). Model B outperformed the conventional model in terms of pressure drop and heat resistance, achieving improvements of 46% and 40%, respectively. Furthermore, Model D outperformed Model B in Nusselt number by 31.375%. Notably, Model D showed the highest OPF and most consistent core temperature among the models, confirming its status as the ideal design, with an OPF of 2 compared with the conventional model.

Optimization of Thermal and Pressure Drop Performance in Circular Pin Fin Heat Sinks Using the TOPSIS Method

This study aims to optimize the thermal performance of pin fin heat sinks by minimizing the maximum temperature of the heat source. Using ANSYS ICEPAK, simulations were conducted for various design parameters, including the number of fins, inlet flow rate, and fin thickness, across circular fins in both inline and staggered arrangements. The circular staggered configuration with 36 fins (3 mm thick) and a flow rate of 6 CFM (Cubic Feet per Minute) achieved the lowest temperature of 34.96 °C, outperforming the inline arrangement. The Taguchi method helped strike a balance between heat transfer and pressure drop, revealing that flow rate has a greater influence when varied compared to the number of fins and fin thickness. An optimal configuration was identified with 36 fins and a flow rate of 4 CFM, which was less sensitive to operational variations. Analysis of Variance (ANOVA) revealed that inlet flow rate significantly impacts heat sink performance, while polynomial regression models demonstrated strong generalization capabilities, with Root mean square error (RMSE) of 8.92%. These findings provide reliable predictive tools and practical insights for optimizing heat sink designs in electronics cooling applications. By utilizing the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method, the coefficient of relative closeness (Cn*) is plotted as a main effect. Referring to the multi-objective optimization-based TOPSIS method, it is found that the attributes are partly from the inlet flow rate (Q) are 63.4% of the number of fins (Nf) (25.05%).

Convective heat transfer improvement for a horizontal grooved surface by the piezo-fan integration

In this study, the thermal and hydraulic performances of horizontal grooved surfaces subjected to the piezo-fan ( PF) is numerically investigated. A total of four grooved surfaces with varying dimensionless edge length of the square groove cross-section ( EL = 0.25, 0.5, 0.75 and 1) and a corresponding baseline flat surface ( EL = 0) are considered. Two kinds of numerical models are utilized to capture the turbulent characteristics and temperature distribution. The dynamic mesh technique and user-defined function are employed to descript the vibration trajectory of the PF. The focus of this study is on assessing the impact of PF in the design of an active heat sink. It is confirmed that, due to the change in surface geometry, the flow cannot follow the surface contour perfectly, leading to a pressure drop and a separation of flow from the grooved surface. The integration of PF into a horizontal grooved surface is a highly efficient means for improving heat transfer performance. Its role in heat transfer enhancement is most significant when the dimensionless edge length is EL = 0.75. With the presence of PF, the effective area-averaged convective heat transfer coefficient ( harea,eff) both on flat and grooved surfaces are generally larger than the corresponding one without the PF. Of particular is that the harea,eff of both types of target surfaces reach their maximum within the specified zone S4 (4 APP × 4 WPF), with the grooved surface being approximately 14% to 28% higher than the flat surface. Moreover, the numerical simulation method has been validated through the comparison with a simple heat transfer experiment.

Design of an Axisymmetric Triangular Heatsink with Radial Arrangement: An Experimental Investigation of Natural Convection Heat Transfer

Radial heat sinks are often employed as heat transfer enhancers because they increase the heat transfer surface area. Novel shapes of fins are used to enhance thermal heat performance under free convection heat transfer. The present experimental study investigates a new-fin shape effect on the thermal behavior of a radial heat sink with a circular base. The objective is to select the best reference model by comparing the three heat sink models, I, II, and III. The study was conducted for the heat-supplied rates of 20.16, 66.03, 105.30, 157.62, and 196.08 W. The present results showed that the fin in case I configurations dissipated heat transfer up to 12.07% and 30% compared to cases II and III, respectively, at high Rayleigh numbers. The thermal resistance in case III reduced to 13.91% and 16.23% compared to case I and case II, respectively, at the maximum Rayleigh number value. Then, based on experimental data, a correlation was suggested to estimate the Nusselt number for free convection from radial heat sink with vertically oriented double triangular fins.

Feature analysis aided design of lightweight heat sink from network structures

Feature analysis aided design of lightweight heat sink from network structures

Optimizing Heat Sink Design: Achieving an Enhanced Heat Dissipation through Oval Perforation

Optimizing Heat Sink Design: Achieving an Enhanced Heat Dissipation through Oval Perforation

Experimental study on flow boiling of fluorocarbon fluid in the pin-ribbed micro-channel with rigid tails

In this work, a novel type of pin-ribbed micro-channel with rigid tails is designed based on the conventional pin-ribbed micro-channel. A comparative experimental study is carried out using fluorocarbon fluid Novec649. The flow boiling heat transfer and pressure drop characteristics are investigated under horizontal/vertical placement at inlet subcooling temperature of 25 °C. The ranges of inlet mass flux and heat flux are 519–1818 kg·m−2·s−1 and 50–500 kW·m−2, respectively. The results show that at a given mass flux, and heat flux of 300–500 kW·m−2, the vertical pin-ribbed micro-channel with rigid tails has the lowest average wall temperature, the largest average heat transfer coefficient, and the smallest total pressure drop, therefore it has the largest j-factor, more than 60% higher than that of the horizontal/vertical channel without rigid-tails. With the aid of a high-speed camera, the localized bubble movement phenomena in horizontal/vertical micro-channel with rigid tails was photographed at a mass flux of 519 kg·m−2·s−1 and a heat flux of 100 kW·m−2. Three types of bubble detachment modes in the wake region at the boiling stable state are observed: natural shedding, one-sided shear and two-sided shear. The bubble detachment diameter under the one-sided shear is more than 23% smaller than that of two-sided shear, and that of the horizontal channel is more than 44% higher than that in the vertical channel, whereas its bubble detachment frequency is only 50% of that in the vertical channel. Therefore, the vertical placement is more helpful for the rigid tails playing a role in the breakup and detachment of bubbles. The experimental results confirm the advantages of adding rigid tails behind the square-rib to enhance the comprehensive heat transfer performance of flow boiling, which can provide a guidance for the structural design of two-phase miniature heat sinks.

Numerical Analysis of the Thermal Performance of a Hybrid Heat Sink Comprised of Perforated Foam Fins Embedded Within a Phase Change Material

ABSTRACTThis study presented a numerical model to evaluate a novel design of a hybrid heat sink incorporating perforated foam fins (PFFs) instead of solid fins (SFs) within a phase change material (PCM). This innovation is designed to enhance thermal performance in electronic cooling applications. The base of the heat sink was subjected to constant heat fluxes of 2, 3, and 4 kW/m2. The effect of the perforation location (top, center, and bottom) within the foam fin and foam porosities (0.85, 0.90, and 0.95) were investigated. The results showed that the hybrid PFF design demonstrably improved thermal efficiency compared to the SF configuration. This innovative approach offered three benefits: a significant reduction in overall heat sink weight, an augmentation of the thermal conductivity of PCM, and the intermixed molten PCM between the fins passages through perforations. The PFF heat sink extended the operational time by 6%–8% for the range of heat fluxes at SPT of 70°C and led to a 24.5% increase in PCM volume, compared to the SF configuration. Complete melting of the PCM in the PFF heat sink is observed at 29 min for the highest heat flux of 4 kW/m2, while the melting rates are 25% and 62% for the applied heat flux of 2 and 3 kW/m2. Perforation location within the foam fin (top, center, and bottom) achieved equivalent heat transfer capabilities, enabling design flexibility for perforation location. The PFF with a porosity of 0.85 demonstrated superior thermal performance.

Novel design of centralized square array of pin-fins in microchannels heat sink for thermal management of high concentrator photovoltaic systems

High concentrations of direct normal irradiation on photovoltaic cells can cause a substantial rise in the cell’s temperature, leading to a decline in performance and potential damage to the cell. Therefore, maintaining low and uniform temperatures in solar cells is crucial for enhancing reliability and optimizing the performance of high concentrator photovoltaic systems. By placing the solar cell layer centrally and integrating a centralized square array of pin-fins within rectangular microchannels, cooling performance can be greatly improved. This study proposes a novel heat sink design incorporating a centralized square array of pin-fins in rectangular microchannels, specifically aimed at efficient active cooling of high concentrator photovoltaic systems. The investigation was conducted under a concentration ratio of 1000 suns and mass flow rates of water coolant ranging from 15 to 1000 g/min with the inlet temperature of 25 °C. The number of centralized square array of pin-fins were varied with the aim of obtaining the best design of square array of pin-fins that provides efficient cooling of solar cell with minimum temperature non-uniformity distribution. The results revealed that the number of square arrays of pin-fins have significant effect on the cell temperature, temperature uniformity, cell efficiency, net electrical power, thermal and exergy efficiency. For all design cases, the non-uniformity temperature of the cell declines with increase in mass flow rates, and the minimum value of 9.50 K for a design case 4 with 7-square array of pin-fins was achieved at the mass flow rate of 1000 g/min. The net electrical power peaks at 35.825 W for the design case 8 as the mass flow rate increases from 15 to 200 g/min. However, as the mass flow rate further increases from 200 to 1000 g/min, the net power decreases due to increased pumping power with design case 1 and 8 experiencing the minimum and maximum percentage reduction of 0.231 % and 6.606 % respectively. CFD code was utilized for the computations and validated with the available data in an open literature.

Vapor separation in minichannel heat sink flow boiling application using gradient porous copper ribs

The accumulation of a significant amount of vapor in minichannels severely limits their flow boiling heat transfer performance, posing a challenge for efficient thermal management in high-power electronic devices. To address this issue, we propose an innovative gradient porous copper rib minichannel with a vapor separation function. This design incorporates micro-pore porous copper and open-cell porous copper, where the unique structure of the micro-pore porous copper is crucial for achieving effective vapor separation. This innovative design not only expands the vapor discharge pathways within the minichannel but also significantly enhances the overall efficiency of vapor removal. Using water as the working fluid, flow boiling experiments were conducted across a range of mass fluxes (G = 26.1 kg/(m2s) ∼ 156.9 kg/(m2s)) and heat fluxes (qeff = 38.2 kW/m2 ∼ 267.5 kW/m2). The experimental results demonstrate that vapor separation significantly alleviates backflow and enhances heat transfer performance. Specifically, our findings indicate that the average temperature of the heat transfer surface decreases by 0 to 10 °C, while the maximum heat transfer coefficient increases by 2.3 times compared to conventional designs. This work presents a practical and innovative approach to mitigating vapor accumulation in minichannels, providing valuable insights for the design of high-performance minichannel heat sinks.

Thermal characterization methodologies for experimental minichannel heat sink designs in printed circuit board assemblies

There has been a growing demand for novel, highly efficient, power-saving cooling solutions in recent years. In many cases, standard cooling techniques offer only limited opportunities to prevent the overheating of circuits. Such issues concern high-speed Printed Circuit Board Assemblies (PCBA) in data centers and telecommunication racks, where the flow of the cooling medium is obstructed due to the lack of space. Size limitations can also be a serious problem when cooling high-power devices because the devices consume a large space. Since the heat sink-based cooling solutions and the sophisticated IC packages only deal with one possible heat flow path, we were given the idea of enhancing the secondary heat flow path towards the Printed Circuit Board (PCB). Led by this intention, the idea of creating an embedded minichannel system inside the circuit board and circulating the cooling agent was realized. Through this method, we could decrease the board-to-ambient thermal resistance significantly. This paper presents the demonstration and feasibility study of this method. One of the main aims of this study is to demonstrate the applicability of the proposed concept in PCBAs, where the primary concerns are the low-cost manufacturability and available space. The other goal is to create an adaptation of the standard thermal characterization methodologies to deal with the specific dissipating components in the PCBA demonstrators. In the first part, the manufacturing technology is elaborated on, and its efficiency is characterized by thermal transient testing and Computational Fluid Dynamics (CFD) simulations. For these use cases, it was noted that the cumulative thermal resistance decreased by approximately 60 % when a volumetric flow rate of 100 ccm was applied in the minichannels. In the second part, a more sophisticated technology demonstration is realized and characterized by adding the proposed embedded minichannel heat sink to an existing high-speed PCBA. A specific thermal transient testing was implemented specifically for this use case, and it was carried out on programmable logic devices by utilizing general-purpose programmable logic to construct the necessary measurement methods. In the future, this feature can be used in different logic circuit designs where it is not possible to determine the junction temperature directly.

Microchannel heat sinks for hotspot thermal management: achieving minimal pressure drop and maximal thermal performance

In hotspot regions, where heat flux can reach several orders of magnitude higher than in surrounding area, managing hotspot temperatures becomes a prominent issue. This study introduces three innovative heat sink designs that effectively manage high temperatures in hotspot regions while minimizing power consumption. The hydraulic and thermal performances of these designs were evaluated numerically and compared with those of the conventional straight parallel microchannel (SPMC) heat sink and previous designs from the literature. By integrating pin-fins in hotspot regions and positioning the fluid inlet above the hotspot to leverage jet impingement, these designs significantly improved the heat transfer coefficient in hotspot areas. The MMC structure, featuring a manifold configuration, achieved an 81.4 % reduction in pressure drop compared to the SPMC design. The RMC structure demonstrated superior temperature uniformity. Additionally, the impact of the jet inlet angle on the hydraulic-thermal performance of the RMC heat sink was investigated. The AMC structure, which integrates the benefits of both RMC and MMC, achieved an impressive 87.9 % reduction in pressure drop compared to the SPMC design, underscoring its advanced performance.

Investigation of Heat Transfer Enhancement Techniques in Microchannel Heat Sinks

The present work reviews the extensive literature concerning heat transfer enhancement techniques for microchannel heat sinks for improved thermal performance in high density power electronics applications. This paper will discuss and analyze passive and active techniques with an employment of surface modification, enlarged surface area, oscillating flow, incorporating PCMs and by utilizing the EHD technology. The outcome of the experiment show that enhancement of EHD provides the biggest heat transfer coefficient and substantial increase in heat rejection capability. But they also cause a greater pressure drop, in this case illustrating the common trend of thermal performance and system efficiency. One can also use extended surfaces and phase change material to realize minimal thermal resistance while at the same time controlling for the pressure drop. This paper offers a comparison of these methods, while stressing that the selection of enhancement procedure should he based on the function or application at hand. The results can be considered useful for better understanding of microchannel heat sink performance characteristics and contribute substantially to electronic cooling and heat rejection applications. Areas for future work include the identification of new enhancement types that can be used in microchannel heat sink designs as well as the study of different enhancement techniques to develop the best performing and most efficient design.

Innovative heat sink design for enhanced cooling efficiency in Dual Active Bridge (DAB) topology

Abstract After in-depth research and analysis, aiming at the heat generation mechanism and limitations of the current heat dissipation method, this paper proposes an innovative heat dissipation design scheme. By optimizing the structural design of the heat sink, the heat dissipation surface area is increased, thus achieving more efficient heat emission and maintaining the optimal operating temperature of the equipment. Experimental data show that this new heat dissipation design significantly improves the cooling efficiency, an increase of about 60%, and provides support for the performance improvement of high-power power products, which brings a reliable and efficient cooling solution for related industries.

Fabrication of microchannel heat sink using additive manufacturing technology: A review

Additive manufacturing is a cutting-edge process that enables the creation and development of complex shapes, opening new avenues for advanced heat sink designs that maximize heat transfer while minimizing pressure drop. This review provides an overview of recent results and insights from global researchers on the additive manufacturing of microchannel heat sinks. It discusses various novel microchannel heat sink types fabricated using additive manufacturing and the complexities involved in their fabrication. Additionally, the review explores geometric configurations, the application of computational optimization methods, and the impact of surface roughness on heat transfer and pressure drop. The primary focus is on the fundamental advantages of additive manufacturing in addressing complex heat transfer designs. However, the review also highlights limitations restricting its benefits in specific applications, such as material handling and availability. This review identifies future challenges for creating novel heat sinks with complex geometries and opportunities for advancements in heat transfer technology.

Heat transfer and entropy generation in oscillating lid-driven heat sinks with variable fin configurations

This study investigates the hydrothermal characteristics and entropy generation within a heat sink subjected to oscillating lid-driven motion and featuring various fin configurations. The analysis focuses on the effects of the Strouhal number (St) and Richardson number (Ri) on heat transfer and entropy production. The current study was conducted over 14 frequencies (0 ≤ St ≤ 0.042), 3 Richardson numbers (0.1, 1, 10), and 6 distinct fin configurations. Using numerical simulations, the study reveals that the oscillating motion of the top plate significantly enhances the heat transfer rate, particularly at lower Ri values where forced convection predominates. Increasing the oscillation frequency improves Nusselt number (Nu) up to a certain point, beyond which further increases deteriorate Nu value. The oscillatory motion of the top plate enhances fluid mixing, boosting heat transfer by disrupting boundary layers and generating vortices that facilitate the exchange of mass, momentum, and thermal energy. The arrangement of fins plays a crucial role, with configurations 6 and 3, which have increased free space between fins, exhibiting higher rotational velocities and improved flow penetration, thus demonstrating superior performance. In contrast, configurations 5 and 2 performed the worst due to the height of the middle fin, obstructing fluid motion across the cavity. Entropy generation analysis shows that thermal entropy is the dominant contributor, increasing with lower Ri values due to enhanced heat transfer rates and temperature gradients. The findings provide valuable insights for optimizing heat sink designs and operating conditions to maximize heat transfer efficiency and minimize entropy generation, informing the development of more effective thermal management systems.

Influence of pin fins and channel geometry on the hydrothermal performance of hexagonal mini-channel heat sink for cooling cylindrical batteries

This study numerically and experimentally examined the effects of pin fin configuration and channel geometry on the performance of a hexagonal mini-channel heat sink (HMCHS) to cool cylindrical lithium-ion battery cells. Various configurations of HMCHS with circular pin fins are studied, including circular fins centrally positioned within flat channels, circular fins positioned within grooved channels, circular fins situated within hybrid channels transitioning between wavy and straight channels and circular fins placed within hybrid channels that incorporate secondary flow channels between the primary flow channels. This numerical study utilized the finite volume method to investigate the laminar water flow at Reynolds numbers below 800. Findings showed that the HMCHS exhibited superior thermal performance compared with the conventional cylindrical mini-channel heat sink design. Moreover, the incorporation of pin fins into the HMCHS design was more effective in enhancing the Nusselt number than simply increasing the Reynolds number across various configurations. Meanwhile, the hybrid channel design with secondary channels, combined with the addition of pin fins, achieved the optimal overall performance of the HMCHS, resulting in the highest performance index of 1.88.

Investigating the impacts of heat sink design parameters on heat dissipation performance of semiconductor packages

This study investigates the impacts of various heat sink design parameters on the thermal dissipation performance of semiconductor packages using a heat sink as the thermal solution. A multiphase finite volume model was developed for heat transfer simulations to determine the heat sink and junction temperatures of the semiconductor assembly. Additionally, a heat transfer experiment was conducted to measure these temperatures over time. The numerical predictions closely matched the experimental results, with a maximum disparity of 0.26 % for junction temperature and 0.42 % for heat sink temperature, confirming the reliability of the numerical model. The results revealed that pin fin heat sinks demonstrated marginally superior thermal performance, reducing the junction temperature by 0.05 % compared to parallel heat sinks. Increasing the base area from 20x20 mm² to 50x50 mm² resulted in a significant 31.64 % reduction in junction temperature and a corresponding reduction in heat sink temperature from 60.41 °C to 36.42 °C. Extending fin height from 10 mm to 50 mm led to an 18.73 % decrease in junction temperature and a reduction in heat sink temperature from 46.07 °C to 34.56 °C. Enhancing the base thickness from 2 mm to 15 mm achieved a 24.35 % reduction in junction temperature and a decrease in heat sink temperature from 63.2 °C to 44.05 °C. The study concludes that optimizing these design parameters can substantially enhance heat dissipation, improving the reliability and efficiency of semiconductor devices.