Circular Pin Research Articles

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.

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 and numerical investigation of flow and heat transfer characteristics of teardrop and circular pin fins in a wedge channel

ABSTRACT Pin fin arrays, which have a high heat transfer capacity and minimal pressure loss, are currently being used as the primary cooling technique for the turbine trailing edge cooling channel used in modern gas turbines. To enhance the heat transmission efficiency of the channel, this study proposes the use of a circular-shaped pin and a teardrop pin, through both experimental and numerical investigations. The numerical simulations conducted in the Reynolds number range of 10,000 to 80,000 are used to investigate and compare the flow and heat transfer parameters of a wedge channel which has three rows of staggered circular-shaped and teardrop-shaped pin fins with a diameter of 12 mm. The experiment showed that teardrop pin fns with staggered arrangement has different effect on flow pattern and heat transfer characteristics. Heat transfer is increased by 10.45% when compared to the circular pin fins and the pressure drop of teardrop pin fins is reduced by 54.6%.Therefore thermal performance factor exhibits a 25.4% increase when compared to circular fins.

A computational search for the optimal microelectronic heat sink using ANSYS Icepak

The efficient thermal management of microelectronic devices is crucial for their reliability and performance. Heat sinks, particularly those with inline and staggered fin arrangements, are vital in achieving this goal. This study leverages the advancements in computational fluid dynamics (CFD) software to explore the optimal heat sink design for microelectronic devices. While prior research has extensively investigated heat sink design, this work offers novelty by employing ANSYS Icepak software for simulations. This approach enables a comprehensive thermal performance and pressure drop analysis for two distinct fin cross-sections. The study investigates heat sink assemblies housed within a confined space, simulating a realistic operating environment for microelectronic devices. The heat sink is designed to cool a single heat source (chip) mounted on a substrate board. In this paper, two types of fin sections, circular and conical, are studied for two types of fin configurations, inline (IA) and staggered (SA), which are analysed with 36 fins in each case. Each fin is constructed from aluminium and has specified dimensions. Air serves as the cooling fluid within the cabinet, dissipating heat generated by the chip. When comparing the performance of circular pin and cone fins at the same power and mass flow rate, the results indicated that the maximum temperature for circular pin fins is 0.46% of the maximum temperature for cone fins, and they have a higher pressure drop, especially for staggered arrangements. Moreover, the maximum temperature for staggered arrangements is lower than that for inline configurations by a factor of up to 1.17% and 2.035% for circular fins and cone pin fins, respectively. This article focuses on a deep understanding of the design of microelectronic cooling systems. It aims to continuously improve pressure and thermal efficiency by maintaining the minimum limits of pressure drop within the confined space and obtaining the optimal configuration for efficient heat dissipation.

Optimization of Pin Fins Using Computational Fluid Dynamics and Machine Learning

This paper presents a two-part study focusing on the optimization of pin-fin arrays for gas turbine blade cooling. The first part of the study examines the thermal performance of various pin-fin shapes and sizes using computational fluid dynamics. The study investigates circular, elliptical, hexagonal, and rectangular cross sections, with emphasis on the hydraulic diameter and Reynolds number. Two-dimensional simulations mimicked a confined, staggered array of uniform-sized pins under different inlet conditions. For a hydraulic diameter of 0.053 m and a Reynolds number of 5500, the rectangular pins showed the highest Nusselt number 8.98, 16.01, and 20.62% larger than circular, elliptical, and hexagonal pins, respectively, but also a pressure increase 68.30% higher on average. For a hydraulic diameter of 0.046 m and a Reynolds number of 1000–15,000, it was shown that all shapes have an exponential increase in pressure and a logarithmic decay in the Nusselt number. Standing out was the rectangular shape, which, at a maximum Reynolds number of 15,000, had a pressure increase of 108% larger than the next in line, the hexagonal pin. In the same range of inlet conditions, the Gee–Webb coefficient was the highest for the circular pin, which was selected as the main shape for the following segment. In the second part of the study, a machine learning framework based on a neural network architecture is presented. The neural network predicts the thermal performance of different pin-fin array configurations. At the end, this framework is used in an optimization process that explores the advantages of nonuniform arrays consisting of differently sized circular pins as opposed to the standard uniform structures of the first part. The model proves to be capable of accurately predicting the characteristic thermal performance coefficients across a wide range of input parameters. The nonuniform array managed a 23% reduction in pressure rise at a 0.2% exit temperature increase compared to a reference standard array of the same hydraulic diameter.

A new kinematic model for revolute clearance joints with noncircular bushing and pin in planar multibody systems

Due to manufacturing error and wear, the profiles of bushing and pin in revolute clearance joints are usually non-circular, while traditional kinematic models for revolute clearance joints generally assume a circular profile for the pin or bushing, which may not be able to accurately capture the kinematic behavior of real revolute joints in multibody systems. To this end, a curvature center method was proposed for the kinematic modeling of revolute clearance joints with noncircular bushing and pin. In the proposed method, both the noncircular bushing and pin were discretized, and the curvature center and radius corresponding to each discrete point were then obtained to detect the point of contact between the bushing and pin based on their kinematic constraints. The number of discrete points was determined based on both accuracy and efficiency of the proposed curvature center method, which was then applied to model a revolute clearance joint between the slider and the link of a slider-crank mechanism. Via comparison to the traditional geometric center method and discrete point method, it was validated that the proposed method can achieve a comparable accuracy in modeling revolute joints with a circular pin. The unique advantage of the proposed curvature center method is its ability in modeling revolute joints with noncircular bushing and noncircular pin, which was also demonstrated via a series of simulations. Simulation results show a significant influence of noncircular bushing and noncircular pin on the dynamic response of the multibody system. This implies the promising value of the proposed method in studying the effect of manufacturing error or wear of both bushing and pin on the system’s dynamic performance and/or service life.

Computational analysis of microchannel heat sinks with constant circular pin fins: Performance evaluation and optimization

This research entails a comprehensive computational simulation aimed at comparing the performance of microchannel heat sinks (MCHS) featuring 55-pin fins, characterized by constant circular pins with a diameter of 15µm, uniform spacing of 50µm, and variable heights ranging from 60 to 35µm. The primary objective was to assess the performance of these models with a reference Mini channel. Mesh independence validation was meticulously executed on MCHS with pin fins to ascertain the accuracy of the computational findings. The simulation encompassed seven Reynolds numbers within the range of 500–1500. The performance evaluation incorporated hydraulic and thermal factors, specifically pressure drop, Nusselt number, and the thermal performance factor (TPF). A holistic assessment of overall performance was achieved through the establishment of a heat sink thermal performance factor, accounting for both hydraulic and thermal aspects. The optimal geometry was determined based on this factor, and corresponding visual representations were generated to illustrate these findings.

State-of-the-art silicon carbide diode dosimeters for ultra-high dose-per-pulse radiation at FLASH radiotherapy

Objective. The successful implementation of FLASH radiotherapy in clinical settings, with typical dose rates >40 Gy s−1, requires accurate real-time dosimetry. Approach. Silicon carbide (SiC) p–n diode dosimeters designed for the stringent requirements of FLASH radiotherapy have been fabricated and characterized in an ultra-high pulse dose rate electron beam. The circular SiC PiN diodes were fabricated at IMB-CNM (CSIC) in 3 μm epitaxial 4H-SiC. Their characterization was performed in PTB’s ultra-high pulse dose rate reference electron beam. The SiC diode was operated without external bias voltage. The linearity of the diode response was investigated up to doses per pulse (DPP) of 11 Gy and pulse durations ranging from 3 to 0.5 μs. Percentage depth dose measurements were performed in ultra-high dose per pulse conditions. The effect of the total accumulated dose of 20 MeV electrons in the SiC diode sensitivity was evaluated. The temperature dependence of the response of the SiC diode was measured in the range 19 °C–38 °C. The temporal response of the diode was compared to the time-resolved beam current during each electron beam pulse. A diamond prototype detector (flashDiamond) and Alanine measurements were used for reference dosimetry. Main results. The SiC diode response was independent both of DPP and of pulse dose rate up to at least 11 Gy per pulse and 4 MGy s−1, respectively, with tolerable deviation for relative dosimetry (<3%). When measuring the percentage depth dose under ultra-high dose rate conditions, the SiC diode performed comparably well to the reference flashDiamond. The sensitivity reduction after 100 kGy accumulated dose was <2%. The SiC diode was able to follow the temporal structure of the 20 MeV electron beam even for irregular pulse estructures. The measured temperature coefficient was (–0.079 ± 0.005)%/°C. Significance. The results of this study demonstrate for the first time the suitability of silicon carbide diodes for relative dosimetry in ultra-high dose rate pulsed electron beams up to a DPP of 11 Gy per pulse.

Improving thermal performance of turbine blade with combination of circular and oblong fins in a wedge channel: a numerical investigation

Abstract Because of its narrow and aerodynamic design, cooling the trailing edge of a turbine blade offers an essential problem. For the trailing edge internal cooling of gas turbine blades, wedge-shaped channels are used. Pin-fin arrays play a critical role in enhancing heat transmission at the trailing edge of turbine blades. The flow and heat transfer properties of a number of wedge channels with staggered pin-fins of varied shapes are used to develop a design with a more effective heat transfer effect and reduced flow resistance. The present study compares the combination of circular pin fins and oblong pin fins in a wedge duct with a Reynolds number range of 12,000–85,000 and a constant heat flux (surface) of 3280 W/m2 applied to the bottom wall, top wall, and surfaces of the fins. The results indicate that the pressure loss is less in circular fins at the centre and oblong fins side by side, and it is 23.67 % less than circular and oblong fins in opposite positions. The Heat transfer coefficient for circular and oblong fins in opposite positions is 16.72 % higher than circular fins at centre and oblong fin side by side. The thermal performance factor is almost the same for both cases.

Numerical study and optimization of thermal efficiency for a pin fin heatsink with nanofluid flow by modifying heatsink geometry

This paper presents a numerical study on the thermal efficiency of a pin fin heatsink (HEK). The working fluid used is an alumina/water nanofluid, which enters the HEK in a laminar flow regime and exits from its surroundings. This study involves varying the distance between circular pin fins, their height, and their diameter. By altering these parameters, we determine the values of thermal resistance (THR) and temperature uniformity (Teta) on the HEK, along with the heat transfer coefficient (HTC). We further optimize the obtained results using artificial intelligence techniques to minimize the THR of the HEK, maximize the HTC, and achieve the best Teta on the HEK. This numerical investigation employs a two-phase approach to model nanofluid flow within the HEK. The optimization process yields predictions with an accuracy of less than 4%. The findings reveal that increasing the height of the pin fins reduces the HTC and the heat capacity of the HEK, while simultaneously improving the Teta on the HEK. Expanding the distance between pin fins enhances the HTC, decreases the THR of the HEK, and further improves the Teta on the HEK. Similarly, augmenting the diameter of the pin fins amplifies the HTC, reduces the THR, and enhances the Teta on the HEK.

Influence of pin-perforation shape on thermohydraulic performance of circular pin-fin heat sinks under turbulent flow

The impact of pin-perforation shape on the thermohydraulic performance of circular pin–fin heat sinks (CPFHS) under turbulent flow conditions is numerically assessed using a computational fluid dynamics software. The convective heat transfer efficiency, hydraulic resistance, and thermohydraulic performance of four pin-perforation shapes: square diamond, triangle, hexagon, and circle, are evaluated under various turbulent flow conditions (Reynolds number between 24,484 to 55,088). The sizes of all pin-perforation shapes are under a constraint that the ratio of the air–solid interfacial surface area to the total volume of pin-perforated CPFHS must be the same. The results show that all pin-perforated CPFHS demonstrate a higher Nusselt number compared to unperforated CPFHS. Those with circular perforations exhibit the highest Nusselt number with up to 39% improvement compared to unperforated CPFHS, followed by those with hexagonal, triangular, and diamond perforations, respectively. The Nusselt numbers correlate with the ease of fluid flow within perforations which is expressed using the average air velocities through perforations. In terms of hydraulic resistance, all pin-perforated CPFHS exhibit a reduction in friction factor compared to unperforated CPFHS. Among these, the largest decrease in friction factor, up to 15.8%, is observed in CPFHS featuring circular perforations, followed by those with hexagonal, diamond, and triangular perforations, respectively. The friction factors are influenced by the ratio of perforation perimeter to cross-sectional area. All pin-perforated CPFHS have a thermal performance factor greater than 1, indicating an improvement in thermohydraulic performance compared to unperforated CPFHS. CPFHS with circular perforations yield the highest thermal performance factor, reaching up to 1.44, followed by hexagonal, triangular, and diamond pin configurations, in descending order. With increasing Reynolds numbers, thermal performance factors of pin-perforated CPFHS initially rise, then gradually decline, suggesting that thermohydraulic advantages due to pin–fin perforations are diminishing as the flow become more turbulent.

Study of orientation effects to pool boiling heat transfer performance from the circular pin fins structure

Increasingly sophisticated technological advances generate heat that needs to be managed properly to ensure the optimality of the operation of these components. One solution offered is the pool boiling cooling method, which has a high heat transfer coefficient. This research aims to study how the orientation angle of the boiling pool affects the heat transfer coefficient. This approach aims to improve cooling effectiveness, especially in the context of moving systems, where the influence of orientation angle is an important factor. In the research related to pool boiling, various orientation angles from 0° to 20° were used on aluminum-based fins in the form of inline pin fins. These fins have a circular shape with a size of 30 mm × 30 mm. The working fluid used in this study is HFE-7100, which has dielectric properties. This study was conducted with heat levels ranging from 10 to 50 W before reaching the Critical Heat Flux (CHF) value. The results show that the orientation angle has a significant impact on the heat transfer coefficient as well as the dynamics of bubble formation. The results also indicate that the greater the orientation angle, the smaller the area of spread and bubble growth that occurs. This decrease in bubble growth area results in an increase in surface temperature. With the circular pin fins test specimen, an increase in surface temperature was found in this study, when the angle θ = 10° amounted to 1.08℃, for the angle θ = 20° amounted to 2.37℃ under the condition of q'' = 55.56 kW/m2. While the highest average value of heat transfer coefficient occurs at angle θ = 0°, the value reaches 3.91 kW/m2∙K and decreases at angle θ = 10° by 3.79%, for angle θ = 20° by 6.56%

Thermal Analysis of Pins and Plate Fin Profiles by using Ansys

The engine compartment is one of the essential components of the engine exposed to excessive temperature differences and thermal stress. Fins are positioned on the surface of the cylinder to improve heat exchange by convection. The present study concerns the study of heat exchange between plate fins and pin fins. Pin fins assembled in two shapes (circular, rectangular) with tubular section to allow better improvement of the heat exchange rate. We have optimized the heat exchange rate and optimized all perspectives to achieve a higher heat exchange rate. In the present work, experiments were conducted to determine the temperature fluctuations inside the fins fabricated in three types of geometries (plate fins, circular pin fins, and rectangular pin fins) and study the coherent-state heat transfer was used using ANSYS finite element software to test and approve the results. Temperature fluctuations in different areas of the pin fins are evaluated using FEM, and the plate fin results are compared with the experimentally determined pin fin results in Ansys. The principle implemented in this design is to increase the heat dissipation rate by using wind flow. The main objective of the study is to improve the thermal properties by modifying the geometry, material and design of the fins

Experimental investigation of forced convection heat transfer for different models of PPFHS heatsinks with different fin-pin spacing

Cooling of electronic components is one of the most important concerns of manufacturers. Using heatsinks with different models is one of the recommended methods for cooling. To compare 12 types of heatsinks, including 3 types of fin-pin heatsinks with rectangular pins, 3 types of fin-pin heatsinks with circular pins, 3 types of fin-pin heatsinks with conical pins, and 3 types of simple fin heatsinks in 5, 7, and 9 fin types regarding forced displacement heat transfer, an experiment was conducted. A special setup designed and built for these types of heatsinks was used to conduct the test. The setup had dimensions of 100 cm × 12 cm x 3 cm with an opening of 120 cm × 120 cm for placing a fan to create airflow with variable speeds and a place for placing the heatsink at the end of the wind tunnel under variable temperatures. The test results showed that the maximum error in the two experimental tests was 6 %. Also, the results showed that in all 4 types of heatsinks, 7-fin pin types had 4 to 20% lower thermal resistance and 20 to 100% higher convection heat transfer coefficient compared to the 5- and 9-fin pin types respectively. When comparing the heatsinks with the same number of fins, it was observed that the 7 and 9-fin types of heatsinks with conical fins have lower thermal resistance and higher convection heat transfer coefficient than other types of heatsinks with the same number of fins, The conical fins having more than 81 % convection heat transfer coefficient compared to the plate fin heatsink. It was also observed that in the 5-pin fin heatsink design, the plate-fin heat sink had the lowest amount of heat resistance due to its higher surface area with the flowing air current.

Taguchi optimization and thermoelectrical analysis of a pin fin annular thermoelectric generator for automotive waste heat recovery

Enhancing thermoelectric performance while minimizing exhaust back pressure is a crucial step in advancing the commercial viability of automotive thermoelectric generators. To achieve high overall performance in a thermoelectric generator, an annular thermoelectric generator equipped with circular pin fins is proposed. A comprehensive three-dimensional numerical model is established to accurately predict thermoelectric performance and thermomechanical behavior. Detailed multi-physics field distribution characteristics are analyzed. Using an L25 orthogonal array, we examine five influencing factors and their five levels: exhaust temperature, exhaust mass flow rate, fin height, fin diameter, and the number of fins. The Taguchi analysis suggests that exhaust temperature is the most influential factor in determining thermoelectric performance, followed by mass flow rate, fin height, fin diameter, and fin number. The optimal values for these parameters are 673 K, 30 g/s, 20 mm, 3 mm, and 420, respectively. Under the optimal design parameters, the net power reaches 34.11 W, representing an 18.7% increase compared to the original design. Moreover, a comparative study is conducted between plate fins and pin fins, showing that the pin fin-based thermoelectric generator exhibits a 5.83% increase in output power and a 4.82% increase in maximum thermal stress compared to the plate fin-based thermoelectric generator.

Artificial intelligent modeling and optimization of pin-fin configuration on the thermal performance of two tubes inside phase change material for cooling of a solar panel using Ag-water nanofluid

This paper performs a two phase numerical analysis on a solar thermal panel of dimensions 80 × 100 cm in the presence of Ag-water nanofluid flow. The nanofluid flows in two individual tubes beneath the panel, and there are some circular pin fins on the tubes. Tubes and pin fins under the panel are surrounded with a phase change material (PCM), paraffin wax. By increasing the length of pin fins from 1 to 7 cm, the volume fraction (VOF) of molten PCM, outlet nanofluid temperature (T-NF), and heat transfer coefficient (HTC) are examined from the transient state up to reaching the steady state. Utilizing a FEM based on a weak form, namely Galerkin, to find a numerical solution for mathematical modeling. Results of this study indicated that increasing the length of pin fins from 3 to 7 cm maximally increases the outlet nanofluid flow up to 2.11 °C. In the transient conditions, increasing the length of pin fins decreases the VOF of molten PCM. When the problem is evaluated in the transient conditions, increasing the length of pin fins decreases the mean temperature of the panel (T-PL), but in the steady-state conditions, the T-PL is the same for different lengths of pin fins. The lowest value of the HTC occurs for pin fins of length 3 cm, and in most cases, the average HTC is maximum for pin fins of length 1 cm.

Endwall heat transfer in wedge channel with teardrop pin fins, circular fins and oblong pin fins

Abstract The turbine inlet air temperatures exhibit a significant degree of elevation, hence leading to potential adverse consequences such as the degradation of blade material integrity. Consequently, the necessity to cool the turbine blades has arisen, leading to the implementation of various cooling systems. This study aims to conduct a comparative analysis of three different types of pin fins, namely oblong, circular, and teardrop, in a wedge duct. The range of Reynolds number considered for the analysis is between 10,000 and 70,000, whereas the pin fins and endwalls are subjected to a uniform heat flux of 3280 W/m2. The findings suggest that the friction factor associated with teardrop pin fins is 28.4 % lesser than circular pin fins and when compared to oblong pin fins; it is reduced by 34.5 %. The findings suggest that the friction factor associated with teardrop pin fins is 14 % lower compared to oblong and circular pin fins. The TPF improves with Re, and it is 24.5 % higher than oblong pin fin geometry and 39.2 % higher than circular shaped pin fins.

Numerical study about thermal performance evaluation of PCM and PCM/fins composite-based thermal control module at microgravity conditions

Satellite subsystems are becoming smaller and have extra power density. There are only two types of heat transport in space: conduction and radiation, making thermal management more difficult. For the thermal regulation of satellite subsystems, thermal energy storage materials are appropriate. In the present study, small satellite subsystems were controlled using a phase change material (PCM)-based heat sink. The design of the aluminium heat sink was according to the outside dimensions of the subsystem in a small satellite. The PCM material used in the work was RT 35. Integrated fins of various shapes were used to overcome PCM's poor thermal conductivity. Three fin geometries were investigated: parallel fins, cross fins, and pin fins. Three shapes of pin fins were evaluated: square pin, circular pin, and triangular pin fins. The heat sink was exposed to a thermal cycle with 80 min cooling and 10 min heating processes. The results reveal that pin fins have better thermal performance than cross and parallel fins. For pin fins, the triangular pin fin provides the best thermal performance among all cases. Maximum temperatures reported for triangular pin fin were 41.5 °C with a 10.8 % reduction. The results indicated a considerable improvement in thermal performance by increasing the number of pin fins.

Artificial intelligence-based entropy generation investigation of two-phase nanofluid flow in a heatsink with pin fins

It is crucial to assess the efficiency of using entropy generation (EYG) in energy-consuming devices. In this article, a study is done on the EYG of laminar water/alumina nanofluid (NFD) in a heatsink (HTK) with circular pin fins. The NFD enters the middle of the HTK and exits around it and passes through the pin fins. The bottom portion of the HTK is subjected to a steady flux, and the temperature of the HTK is lowered by the cold NFD. By changing the diameter and height of pin fins and their distance, the values ​​of thermal EYG (TEYG), frictional EYG (FEYG), and total EYG (TOEYG) are estimated and the contours of temperature and NFD flow are presented. An optimization is performed on the results by using the response surface method (RSM) in the range of the studied variables to obtain minimum amounts of EYG and HTK temperature. The finite element method (FEM) and the two-phase mixture method are utilized to simulate the NFD flow. The findings show that increasing the height of the pin fins decreases thermal and TOEYG while increasing FEYG. Enhancing the distance between the pin fins, leads to a slight decrease in thermal and TOEYG.

Numerical investigations of heat transfer characteristics using oblong fins and circular fins in a wedge channel

Abstract Turbine inlet air temperatures are extremely high, which can result in blade material damage. As a result, cooling the turbine blades is required, and a variety of cooling techniques have been introduced. The majority of the previous research on pin fins has focused on circular fins using a wedge duct to apply a constant temperature and uniform heat flux to the end wall and pin fin surfaces. The present study compares seven oblong pin-fins to seven circular pin fins in a wedge duct with a Reynolds number range of 10,000–50,000 and a constant heat flux (surface) of 3280 W/m2 applied to the endwall and surfaces of the oblong pin fin. The results indicate that the friction factor for oblong fins is 14% lower than for circular pin fins. The thermal performance factor is increased by 11.4%. The thermal performance factor can be improved by using oblong pin fins with higher Reynolds numbers.