Pin Fin Heat Sink Research Articles

Thermo-hydraulic investigation of open micro prism pin fin heat sink having varying prism sides

The current trend of miniaturization in many electronic devices, like computer processors, high-speed servers, MEMS devices, etc., has shown augmented performance. Still, thermal management is a significant concern for them. The present work performed a numerical analysis on the microchannel heat sink's open micro prism pin fin configuration (MCHS). The influence of prism pin fin sides (3 to 9) has been studied for copper substrate and working fluid water (single phase fluid flow). Finite volume-based commercial code has been opted to perform the numerical simulations. The present configurations simulated different Reynolds numbers (50–300) under the heat flux of 500 kW/m2. Observation revealed that the four-side arrangements have the best performance due to prominent secondary flow leading to efficient fluid mixing, whereas three-side configurations have the worst performance. Further, an increase in pin fin sides from 5 to 9 has almost negligible variation in thermal and hydraulic characteristics because of similar fluid flow characteristics. The four-side micro prism pin fin configuration has been further analysed by varying the prism radius from 0.175 mm to 0.325 mm. It was observed that a prism radius between 0.250 mm and 0.275 mm led to optimum overall performance due to more stable secondary fluid flow.

The experimental analysis on the influence of Non-closed droplet shape and location on Thermal/Flow performance of pin fin heat sinks

With the rapid development of electronic technology, high-performance chips and integrated circuits have been used more and more widely. Due to the extremely high heat transfer coefficient, the boiling heat transfer of working medium in micro pin fin channel have attracted more and more attention, and how to effectively meet the requirements of efficient heat dissipation in small space is an important issue. This paper focuses on the irregular structure of pin fin array with a non-closed pin shape, who retains the streamline structure as droplet shape and enhances the heat transfer performance. In this paper, a visualized experimental analysis on the influence of non-closed droplet pin shape and location on thermal/flow performance of pin fin heat sinks have been conducted. Through macroscopic performance and microscopic bubble dynamic behavior, the inner influence law of pin shape, stream orientation, location on thermal/flow performance have been studied. Results show that from macroscopic view, the non-closed pin shape of the micro pin fin array has a great influence on the flow and boiling characteristics. With the increase of Reynolds number, the pressure drop undergoes three stages: rapid rise, rapid decline and then rise again. Similarly, the variation tendency of convective heat transfer coefficient also get through such three stages. All of which corresponding to the flow pattern changes, indicating four heat transfer stages: film boiling, transition period, nucleate boiling, and single-phase flow heat transfer. Besides, for the scale as 40 < Re < 200 as well as 400 < Re < 800, the heat transfer appearance of non-closed droplet pin fin is better than that of droplet one. While for different stream orientations, the general performance of stream orientation with the opening part opposite the upstream direction is better. For the different locations of the front, middle and rear region, the bubble growth diameter in the front region is much larger than that in the middle region of the channel, and more growth time is required, with the bubble disappear - appear- reappearance interval as 0.536 s and 6.110 s respectively. While the growth time and waiting time of the front region with stream orientation B is 4.85 s as well as 0.86 s, which is much shorter than that of the front region with stream orientation A. Through the visual observation of the bubble dynamic behavior in the front section of the micro pin fin array, it could be concluded that with the increase of heat flux,the bubble diameter increases with time. Furthermore, the bubble growth/migration diameter increases first and then decreases with the increase of Re. Moreover, the bubble diameter in zone II is larger than that in zone III. Generally, the comprehensive performance of the non-closed droplet with stream orientation B is the best over the droplet as well as stream orientation A pin fin array, when it is at the range as 300 < Re < 800. Under comprehensive consideration, non-closed droplet with stream orientation B design is recommended, under operating conditions with Re > 300.

Hybrid [formula omitted]-[formula omitted] nanoparticles-based eutectic phase change materials for enhancement of thermal efficiency of pin-fin heat sink arrangement

This work reports the synthesis and characterization of hybrid nanoparticles-based phase change material (HNbPCM) along with a practical approach in the pin-fin heat sink system. In particular, the hybrids of Nickel cobaltite (NiCO4O4) - Nickel ferrite (NiFe2O4) nanoparticles (NiCo−NiFe) were synthesized by traditional sol–gel method. The (HNbPCM) composites were then prepared by suspending the nanoparticles in paraffin wax (PW) and polyethylene glycol-6000 (PEG−6000) eutectic organic PCMs with various weight fractions (ϕ=1%–5%). The surface texture, physical and chemical interaction of hybrid nanoparticles and its dispersion in the HNbPCM composites were comprehensively analyzed. The cyclic thermal stability, thermal conductivity, and charging and discharging of characteristics of the developed nano-composites were also confirmed by transient hot-wire apparatus, thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC). A nanoparticles concentration of 3wt% in the HNbPCM shows a promising enhancement in the thermophysical properties. The thermal conductivity of HNbPCM was improved by 304.4% by adding hybrid NiCo-NiFe nanoparticles with ϕ=5%. In addition to thermal conductivity augmentation, nanoparticles enriched HNbPCM altered the phase transition process and eliminated super-cooling by maintaining the high latent heat capacity of 188.95J/g in the melting phase and 189.70J/g in crystallization phase. A systematic experimental framework of thermal performance characteristics for HNbPCM composite in rectangular pin-fin heat sink subjected to steady state heat transfer for effective and reliable cooling was also studied. The cooling of heat sinks was under testimony at different power inputs, volume fractions and modes of heat transfer in two distinct case studies with and without PCM. A volume fraction of 3wt% shown the best thermal performance with a heat transfer enhancement up to 3.2kW/m2 with 18°C temperature reduction in operational time, specific heat capacity, and thermal conducting ability. An improved thermal performance shows considerable thermal and chemical stability, which can expedite the transition process and makes it a desirable prospect for superior thermal energy storage (TES) applications.

A Variable-Fidelity Multi-Objective Evolutionary Method for Polygonal Pin Fin Heat Sink Design

For the multi-objective design of heat sinks, several evolutionary algorithms usually require many iterations to converge, which is computationally expensive. Variable-fidelity multi-objective (VFO) methods were suggested to improve the efficiency of evolutionary algorithms. However, multi-objective problems are seldom optimized using VFO. Therefore, a variable-fidelity evolutionary method (VFMEM) was suggested. Similar to other variable-fidelity algorithms, VFMEM solves a high-fidelity model using a low-fidelity model. Compared with other algorithms, the distinctive characteristic of VFMEM is its application in multi-objective optimization. First, the suggested method uses a low-fidelity model to locate the region where the global optimal solution might be found. Sequentially, both high- and low-fidelity models can be integrated to find the real global optimal solution. Circulation distance elimination (CDE) was suggested to uniformly obtain the PF. To evaluate the feasibility of VFMEM, two classical benchmark functions were tested. Compared with the widely used multi-objective particle swarm optimization (MOPSO), the efficiency of VFMEM was significantly improved and the Pareto frontier (PFs) could also be obtained. To evaluate the algorithm’s feasibility, a polygonal pin fin heat sink (PFHS) design was carried out using VFMEM. Compared with the initial design, the results showed that the mass, base temperature, and temperature difference of the designed optimum heat sink were decreased 5.5%, 18.5%, and 62.0%, respectively. More importantly, if the design was completed directly by MOPSO, the computational cost of the entire optimization procedure would be significantly increased.

Thermo-hydraulic investigation of two stepped micro pin fin heat sink having variable step size

To achieve enhanced flux dissipation, microchannels heat sink are being effectively implemented in various engineering processes. Here, a numerical analysis is to be carried out on an open stepped micro pin fin heat sink (MPFHS) with different step size. The stepped pin fin heat sink (PFHS) having varied fin height in an array of two fins having inline arrangement. For the simulation purpose, a single-phase water was used as working fluid with variable thermophysical properties. The present configuration has operated for Reynolds number =100-500, heat flux of 500 kW/m2. The step variation of 100 µm, 200 µm and 300 µm has been considered. It was observed that with increase in step size, the heat transfer augmentation also increases. However, at higher Reynold number, the present studies does not provide effective results in terms of sustainability.

Computational and analytical study on CPU heat sink cooling by single and double stack air-foil micro pin fins

The computational and analytical study was carried to study thermal performance of airfoil shaped pin–fin heat sinks. The cooling capacity of heat sink is important for central processing unit (CPU). The heat removal is achieved using air cooling techniques. The computational results of different shapes of pin fins are validated with equation from the available literature. In the present study micro pin fin heat sink with revolved airfoil shape and single, double stack arrangement is used in CFD simulation and results are obtained. The double stack arrangement shows more heat dissipation from heat sink as compare to single stack arrangement.The heat transfer is obtained at different Reynolds number (Re) (using various inlet velocities). The Nusselt number (Nu) increases with increase in air flow velocity which enhance the heat extraction from CPU. The percentage rise in heat transfer using double stack micro pin–fin observed is 12.88% as compare to single stack micro pin–fin when CFD simulation is carried.

A comparative experimental thermal performance analysis of conical pin fin heat sink with staggered and modified staggered layout under forced convection

• An experimental thermal performance study of conical pin fin heat sinks in comparison. • CPFHS mst has the minimum R th and T j in all tests. • CCPFHS perp has the maximum pressure drop in any case. • CCPFHS perp at 33 W and CPFHS mst at 66-99 W has the highest average Nu. • CPFHS mst has a better average THP than other heat sink models for all the powers. In contrast to the common practice of evaluating heat sinks with inline or standard staggered fin placement, this research investigated the thermo-hydraulic performance of conical pin-fin heat sinks with staggered-(CPFHS st ) and modified staggered-(CPFHS mst ) fin placements. The heat sinks with cross-cut pin-fins oriented parallel-(CCPFHS par ) and perpendicular-(CCPFHS perp ) to the airflow and a flat heat sink (FHS) are also used for comparison. The effect of heat sink fin placement on the parameters became remarkable with increasing Re, so the modified staggered fin placement was 2-7 °C lower than the staggered surface and junction temperatures. R th of the modified model compared to the staggered was 5.3%, 5.8%, and 3.5% lower, while the highest ΔP is in CCPFHS perp with 6.7, 6.9, and 7.4 Pa. CCPFHS perp provided a 29.9% advantage of Nu to the modified model, whereas the modified model provided a 6.4% over CCPFHS perp and a 17.4% over the staggered model for the test powers. The modified model provides the highest THP performance, with a 13.3% advantage over CCPFHS perp , 12%, and 10.9% over the staggered model for the test powers. The CPFHS mst is superior regarding thermo-hydraulic performance and is an appropriate option among many heat sink models in the literature.

Investigation of flow and heat transfer behavior of integrated pin fin-aluminum foam heat sink

• A novel aluminium foam heat sink (AFHS) consisting of pin fin inserts is proposed. • The developed mathematical model is validated with experimental data. • Thermo-hydraulic characteristics of proposed heat sinks are numerically studied. • Pin fin inserts lead to an enhancement on the heat removal capability of AFHS. • Pressure drop along the flow direction increases with pin fin insertion into AFHS. With the rapid development in the electronics industry, the thermal management of high power density electronic products (HPDEPs) has become very important and requires innovative heat removal technologies. In this study, an integrated heat sink (IHS) fabricated by combining aluminum foam and pin-finned heat sink configurations that are frequently used in the cooling of electronic products has been proposed as an effective solution for the thermal management of HPDEPs. The heat removal and pressure drop characteristics of the IHS were numerically investigated for its various design conditions such as the length/height ratio ( L/H ), fin profile, fin/foam height ratio ( H fin /H foam ), and heat sink/fin volume ratio ( V hs /V f ) over the range of Reynolds ( Re Dh ) number from 500 to 3500 by using the COMSOL Multiphysics v5.4. Before the numerical study was performed, to verify the outcomes of the developed simulation models, some of the IHS subjected to the numerical study were fabricated and their pressure drop and heat removal performances were experimentally examined in the range of Re Dh from 596 to 3551. As a result of the study, it was found that the thermal contact resistance ( TCR ) between the IHS and the heated surface has a greater effect on the Nusselt ( Nu ) number compared to the TCR between the solid fins and aluminum foam. The in-line or staggered arrangement of pin fins inside the aluminum foam did not lead to any significant difference in the overall performance of investigated IHS. For all the IHS examined, an increase in Re Dh results in a similar increase in the Nu and ΔP along the flow direction. In general, the most efficient IHS among the investigated ones in terms of the H fin /H foam ratio is the IHS with half-length fins, H fin /H foam =15/30. Average values of thermal performance factor ( ƞ) of the IHS with H fin /H foam ratio of 15/30 in in-line and staggered arrangement over the Re Dh number studied are 1.3 and 1.25 times higher relative to IHS with H fin /H foam ratio of 30/15. For a fixed number of fins, η of the IHS with fins of 4mm diameter is superior up to Re Dh =2000, after which, the situation varies in favor of the 8mm solid finned aluminum foam heat sink. Increasing the fin diameter from 4mm to 12mm in both fin configurations worsens the average value of ƞ by 10%. For a constant fin diameter, IHSs with 9 fins in in-line and 8 fins in staggered configuration have the highest ƞ when the Re Dh is greater than 2500 and 2000, respectively. Among the fin profiles examined, the IHS with elliptical fins is found to have the highest η , with a value of 1.24, at Re Dh =3500.

Hydrodynamics and heat transfer characteristics of bio-synthesized SiC-alkaline water and ZnO-alkaline water nanofluids in an aluminum plate pin-fin heat sink

Hydrodynamics and heat transfer characteristics of bio-synthesized SiC-alkaline water and ZnO-alkaline water nanofluids in an aluminum plate pin-fin heat sink

Thermal and exergy analysis of Pin-finned heatsinks for nanofluid cooled high concentrated photovoltaic thermal (HCPV/T) hybrid systems

• Cooling performance of HCPV/T is systematically investigated. • Different shaped pin-finned heat sinks (inline and staggered) are examined. • Thermal performance is determined for MWCNT nanofluids. • Exergy efficiencies of pin-fin heat sinks in HCPV/T are evaluated. • 2% MWCNT nanoparticle concentration is found to be the optimum. Cooling of High Concentrated Photovoltaic (HCPV) cells is a major concern among researchers due to higher heat generation in the cells from highly concentrated solar radiation. In the present investigation, a numerical study of the High Concentrated Photovoltaic Thermal (HCPV/T) system is conducted for the combined effect of nanofluids and pin-finned heatsinks on the cooling performance. The investigation is carried out for AZUR SPACE solar cell (Model: 3C44C) for 1000 Concentration Ratio (CR) and the Reynolds number ( Re ) varies within the laminar range (600 ≤ R e ≤ 2200). Different shapes of pin-fins and their orientations are systematically investigated for the effect of Multi-walled Carbon Nanotube (MWCNT) nanoparticles in a base fluid. The results show a significant reduction in the temperature (up to 18K) of the solar cells for the MWCNT nanofluid compared to its base fluid counterpart. A higher heat transfer characteristics (Nusselt numbers) and lower average temperature of top surface of HCPV cells are found to occur for the staggered arrangements of pin-fins. It is also noticed that the volume concentration of MWCNT in water affects heat transfer characteristics and reduction in temperature takes place up to the volume concentration of 2%. About 1.3% reduction in temperature is predicted for adding MWCNT nanoparticle concentration from 0.5% to 2%. However, in terms of exergy efficiency, maximum overall exergy (about 67% for water flow rate of 0.00167 kg/s) is found for square pin-fins with inline arrangements. The average increase in Nusselt number from inline to staggered arrangement are around 11%, 74%, and 22% respectively for circular, square and triangular fins. The maximum electrical efficiency reaches to 42.2% for both 2% and 4% MWCNT with staggered circular pin-fins for a mass flow rate of 0.0058kg/s. Finally, it appears that a combination of nanofluids and pin-finned heatsinks gives a better cooling rate in the HCPV/T system and could be a promising alternative along with other cooling techniques.

Numerical simulation of the effect of rib spacing on the heat transfer performance of micro pin-fin heat sink

This paper aims to deeply understand the influence of different columnar rib spacing on the comprehensive thermal hydraulic performance of miniature columnar rib radiator, and further explore the influence of flow and heat flow density Taking 10 miniature columnar rib radiator models as research objects, the single-phase heat transfer process of square miniature columnar rib radiator was studied. The experimental results show that for 10 kinds of miniature columnar rib radiators, the relationship between the maximum temperature difference at the bottom of the ribbed substrate will change with the change of temperature, with linear arrangement and cross arrangement.The maximum and minimum values are, respectively, when the longitudinal spacing is 0.75mm and 0.25 mm, and the maximum and minimum values are, respectively, when the transverse spacing is 0.5 mm and 1.25 mm.

Numerical feasibility study of using ultrasonic surface vibration as a new technique for thermal management of the electronic devices

The suitable thermal management of electrical devices leads to their reliable operation and durability. The present study investigates the application of ultrasonic surface vibration in a pin–fin heatsink to improve hydrothermal performance. To this end, a totally 31 scenarios were examined by altering the location of the vibrating transducers at four lateral walls and the top plate of the heatsink. The numerical calculations were performed within Reynolds number (Re) ranges of 500–2000 and frequency magnitude (F) of 15–30 kHz. Our results showed that the heatsink with three transducers at the top plate and two lateral adjacent walls (near and the opposite side of the inlet), namely case#27, exhibits the highest heat transfer coefficient and performance evaluation criteria (PEC) of 1.38 over the base case without transducers (WOT) at Re = 2000 and F = 30 among the studied cases. In addition, case#27 has its highest heat transfer coefficient and pressure drop (ΔP) at Re = 2000, while its maximum PEC is obtained as 1.78 at Re = 1000 for F = 30 kHz over the base case without vibration. Moreover, the maximum heat transfer coefficient and the lowest ΔP for case#27 at Re = 2000 were obtained at = 25 kHz. In such a case, the PEC was obtained as 1.06 over the base case.

Cause analysis on abnormal failure of copper-substrate pin fin heat sink for new energy vehicle

The new energy vehicles are playing more and more important role in energy conservation and environmental protection. With regard to the new energy vehicles, the power module is a key device which converts the direct current (DC) into the alternating current (AC). Considering a great deal of heat generated by the power module during operating, a kind of pin fin heat sinks with nickel-phosphorus coating is specially designed and manufactured, so as to prevent the power module from thermal damage. In view of this, the reliability of the pin fin heat sinks must be strictly evaluated before putting into use. However, during the corrosion resistance tests, some suspected corrosion defects occurred on the pin fin heat sinks, by which the newly-designed pin fin heat sinks were judged as unqualified. Aimed at this special failure, a series of characterization methods and comprehensive analysis were carefully performed. Through systematic assessment and analysis, the so-called local corrosion was excluded and the explosive release of local hydrogen in nickel-phosphorous coating was determined as the root cause of radial defects. Meanwhile, four kinds of typical manufacturing defects for the pin fin heat sinks were characterized and discussions were also given in detail for the formation causes and affecting factors. Based on the obtained conclusions, the effective countermeasures are put forward for improving plating quality and the achievement of the paper is also helpful for better understanding the operating safety and reliability of new energy vehicles.

Experimental Analysis of Nano-Enhanced Phase-Change Material with Different Configurations of Heat Sinks.

The demand for high-performance and compact electronic devices has been increasing day by day. Due to their compactness, excessive heat is generated, causing a decrease in efficiency and life. Thermal management of electronic components is crucial for maintaining excessive heat within the limit. This experimental research focuses on the combined effect of nano-enhanced phase-change material (NePCM) with different configurations of heat sinks for cooling electronic devices. Multi-walled carbon nanotubes (MWCNTs) are used as nanoparticles with concentrations of 3 wt% and 6 wt%, RT-42 as the phase-change material (PCM), and aluminum as the pin fin heat sink material. Different configurations of the heat sink, such as circular, square, and triangular pin fins, are used against the fixed volume fraction of the fins. It is found that the square configuration has the highest heat transfer with and without PCM. A maximum base temperature reduction of 24.01% was observed in square pin fins with RT-42 as PCM. At 6 wt% of NePCM, the maximum base temperature lessened by 25.83% in the case of a circular pin fin. It is concluded from the results that a circular pin fin with NePCM is effective for base temperature reduction, and all fin configurations with NePCM collectively reduce the heat sink base temperature.

Performance Analysis of Central Processing Unit Heat Sinks Fitted With Perforation Technique and Splitter Inserts

Abstract The increase in the heat dissipation rate in heat sinks (HSs), the reduction of the occupied volume and mass, and the elimination of the lower heat transfer areas (LHTAs) behind the pins are the main parameters to be controlled in HSs design. For this purpose, this study is devoted to numerically investigating the effect of the combination between perforation technique and splitters inserts on the heat dissipation and turbulent fluid flow characteristics of pin fins heat sinks (PFHSs). The splitter is located in the back of the pin, and the cylindrical pin fins heat sinks (CPFHSs) are perforated with different pairs of hole numbers. These configurations are named PFHS-0 (without perforation) to PFHS-5. The results obtained for the PFHS-5 show an increase in Nusselt number by 34.91% and a reduction in the thermal resistance by 24.22%, compared with CPFHSs. For the same conditions, the occupied volume and mass of this case are also reduced by 70% and 47.5%, respectively. In addition, the PFHS-5 case ensures the highest hydrothermal performance factor (HTPF) of 1.42 at Re = 8,740.

Numerical study of the influence of the micro pin fin arrangement on the thermal and hydraulic performance of a micro heat sink

In this project, a numerical study of the thermal and hydraulic performance in a micro pin fin heat sink is carried out. The micro heat sinks pin fins are used for cooling of electronic, due that every day a more powerful and smaller chips and electronic components are required. The geometric parameters to the build of the heat sink with micro pin fins are chosen in base of the geometric needs of the electronic chip, a circular geometry is used for the micro pin fin and inline and staggered arrangement for the micro pin fins distribution is used, different velocities in the inlet of the heat sink are used for development of the study. In the result section, the temperature contours and the thermal resistance of the different cases analyzed are reported, as well as the pressures distributions and the total pressure drop along the heat sink micro pin fin are reported too. Taken account the results, the optimal geometry for thermal and hydraulic performance of the heat sink micro pin fin is obtained.

Experimental investigation on flow boiling characteristics of a radial micro pin–fin heat sink for hotspot heat dissipation

The rapid development of integrated circuit technology has led to an increasing chip-level heat flux, which poses a difficult challenge to cooling techniques. A radial micro pin–fin heat sink that combines the merits of micro pin–fin structure and central inlet jet configuration is proposed in this study for heat dissipation of high-heat-flux hotspot. Flow boiling experiments with ammonia are conducted for mass fluxes of 34–182 kg/m2s, heat fluxes of 752–1397 W/cm2, saturation temperatures of 26 and 30 °C, and inlet conditions of near-saturated and two-phase inlet. The rectangular parallel microchannel structure is also tested for comparison. The effects of heat flux, mass flux, saturation temperature, and inlet condition on the heat transfer and pressure drop characteristics are investigated. The governing heat transfer mechanisms of microchannel flow boiling are identified for different experimental conditions. Experimental results indicate that the radial micro pin–fin heat sink can maintain stable and outstanding heat transfer performance over a wide range of experimental conditions, which verifies its application prospect in the heat dissipation of high-heat-flux hotspot.

Heat transfer performance of air-cooled pin–fin heatsinks: a review

Heat transfer performance of air-cooled pin–fin heatsinks: a review

Enhancement of the cooling performance of a pin fin heat sink based on the chimney effect using aluminum tape

Conventional methods of improving the heat dissipation performance of heat sinks require either modifying existing heat sink geometries or installing additional structures to induce chimney effect. These methods can be problematic to apply if there are limitations of space and cost. In this study, we address the aforementioned problems by developing a novel method of inducing the chimney effect by attaching aluminum tape to a pin fin heat sink. Geometric parameters for optimization were the width and attachment position of the aluminum tape, and changes in the thermal resistance of the pin fin heat sink with a rectangular base were observed according to its orientation angle. First, the widths and attachment positions of the outer and inner aluminum tape strips that minimized the thermal resistance of the heat sink were derived through simulation. The thermal resistance of the heat sink was estimated to be reduced by 10.8% or 7.7%, respectively, only by attaching the outer or the inner aluminum tape strip with optimal width to the top of the pin fin, and it was found to be further reduced by attaching both the outer and inner aluminum tape strips simultaneously. As the next step, the simulation results were verified by experimentally measuring the thermal resistance of actual pin fin heat sinks with and without aluminum tape. It was found that the thermal resistance of the pin fin heat sink was reduced by up to 17.1% by inducing the chimney effect simply through the attachment of both the outer and inner aluminum tape strips with optimal widths to the top of the pin fin. For all heat sink orientation angles tested in the range 0°−180°, the thermal resistance was found to be lower when the aluminum tape was attached than when it was not attached. As a result, the heat dissipation performance could be improved without changing heat sink geometry and by requiring no additional space to install a chimney structure. Our study results show that the safety of heat-generating devices that require heat dissipation can be significantly improved by enhancing the heat dissipation performance of heat sinks if the width and attachment position of the aluminum tape are optimized.

Entropy analysis and parametric optimization on the Nano fluid flow and heat transfer of a pin-fin heatsink with the splitter using the two-phase mixture model

The nanofluid (NF) flow rate and concentration (φ) in a pin-fin heat sink with the splitter (WS) were numerically investigated and the optimum Re and φ values were determined by applying a parametric optimization analysis on the thermal and frictional entropy generation rates (S˙th and S˙fr). To this end, the discretization of the governing equation was done by the second-order upwind scheme, the finite volume method. The results were compared with those obtained for the pin-fin heatsink without the splitter (WOS). Based on the findings, the intensification of Re and φ reduces S˙th by almost 43-45% and 10-13%, respectively, for both WS and WOS heatsinks. An insignificant difference between S˙th of two configurations was obtained (0.37-2.93%). Although S˙fr diminishes by 12% as φ intensifies from 0 to 1%, the escalation of Re from 500 to 2000 intensifies S˙fr by 2312% and 4618% in WS and WOS heatsinks, respectively. In addition, S˙fr of WS heatsink is nearly 43-48% lower than that WOS heatsink due to using splitters. The absence of the splitter in the WOS heatsink leads to a delay in flow separation from the pin-fin bodies and deteriorates the heat dissipation, thereby increasing the CPU temperature and S˙fr intensification.