Fin Shape Research Articles

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.

A numerical study of the effect of different geometrical parameters on the cooling processes in electrical transformer

Proper thermal control is one of the most important aspects that should be considered when utilizing electrical transformers. This research work offers a numerical analysis of the effect of changing the shape of transformer fins on the heat exchange process. Based on the results of CFD simulations, several types of fin shapes such as rectangular, triangular and wavy are discussed to describe the improvements of heat transfer. The study examines the shape of an electrical transformer, determining the optimal distance between fins, fin shapes, transformer shape, rib type, and rib number. The results are then applied to a special case, representing the best of all variables on the transformer. The study also considers the effect of increasing the surface area of the ribs on the fins, and the number of ribs used on the fins. The temperature gradient of a coil, oil, and transformer varies depending on the distance between fins, fin shape, rib type, and number of ribs. The coil temperature is 383 K when the fins are 7 cm apart, 381 K when the fins are 5 cm apart, and 381 K when the fins are 3cm apart. The temperature gradient also varies depending on the rib type, with triangular ribs increasing the surface area for heat energy transfer and reducing the temperature value. The oil temperature gradient varies depending on the fins, ribs type, and number of ribs. The heat transfer coefficient gradient of the transformer surface varies depending on the fins, ribs type, and number of ribs. The surface heat transfer coefficient reaches 1.5 W/m2. K when the fins are l shape, 1.6 W/m2. K when the fins are c shape, 1.7 W/m2. K when the fins are z shape, 1.4 W/m2. K when the ribs are rectangular, 1.6 W/m2. K when the ribs are triangular, and 1.4 W/m2. K when the ribs are 9 ribs.

Numerical study of Mg(OH)2/MgO thermochemical heat storage reactor coupled with parabolic dish solar system

Systems coupling Mg(OH)2/MgO thermochemical reactor with parabolic dish solar collector (PDSC) have a potential application prospect in solar seasonal heat storage. However, their working mechanism has not been systematically studied and not well understood either. In this study, Mg(OH)2-based thermochemical reactor, which was coupled with PDSC, was numerically studied for the first time using a three-dimensional model. The various working conditions and influencing factors of PDSC system were investigated, and a comprehensive analysis and optimization for the heat storage performance of the reactor such as the reaction time and energy storage rate were conducted. Effects of the fluid inflow temperature, velocity, and fluid pipe distribution on heat storage performance were also unfolded. For instance, when the heating pipe was arranged at 70 mm from the central axis, the reaction time was 15.9 % less than that of evenly arranged at R/2 from the center. Moreover, fins were added to the reactor and the fin shape was optimized using the density-based topology optimization method. It was found that the reaction time was reduced by 42.4 % and was only 12614 s.

Influence of Coolant Additives and Core Geometry of Fin-Tube Automobile Engine Radiators on the Enhancement of Cooling Process Efficiency

The paper deals with the research on the influence of the shapes of tubes and fins of automobile engine radiators and ethylene glycol coolants of type G12 on the cooling process. This involves cross-flow without mixing of coolant and air. The circular tubes with straight fins are compared with flat tubes with corrugated fins at identical external dimensions of the radiators. The new coolant is compared with the used coolant (10 years of usage) and further with a mixture of the used coolant and the additive (coolant enhancer). The goal is to reduce the heat dissipation time during the cooling process. Forced air convection is generated by three fan variants with diameters ϕ400 mm, ϕ345 mm, and a pair of fans ϕ345 mm and ϕ290 mm. The radiator core with flattened tubes and corrugated fins achieved lower outlet temperatures of 0.35 °C, 1.56 °C, and 2.43 °C compared to circular tubes and straight fins when using the ϕ400 mm diameter fan, the fan pair, and the ϕ345 mm diameter fan, respectively. The addition of the coolant enhancer to the used and new G12 coolant, depending on the fan variant, caused the outlet temperature to decrease in the range of 0.64 °C to 1.47 °C and 0.55 °C to 1.65 °C, respectively. The fan cover is also important for efficient cooling. Refilling of the coolant enhancer in the used coolant ensured that the heat transfer properties were recovered.

Weak integration allows novel fin shapes and spurs locomotor diversity in reef fishes.

In complex functional systems composed of many traits, selection for specialized function can induce trait evolution by acting directly on individual components within the system, or indirectly through networks of trait integration. However, strong integration can also hinder diversification into regions of trait space that are not aligned with axes of covariation among traits. As a result, non-independence among traits may limit capacity for functional expansion. We explore this dynamic in the evolution of fin shapes in 106 species from 38 families of coral reef fishes, a polyphyletic assemblage that shows exceptional diversity in locomotor function. Despite strong shared developmental pathways and expectations of a strong match between form and function, we find that species that share swimming mode show substantial disparity in fin shape, and preferred swimming mode is a poor predictor of fin shape. The evolution of fin shape is weakly integrated across the four functionally dominant fins in swimming (the pectoral, caudal, dorsal, and anal fins) and integration is weakened as derived swimming modes evolve. The weak integration among fins in the ancestral locomotor condition provides a primary axis of diversification while allowing for substantial off-axis diversification via independent trait responses to selection. However, the evolution of novel locomotor modes coincides with a loss of integrated axes of covariation among fins. Our study highlights the need for additional work on the functional consequences of fin shape in fishes and impact of evolutionary integration on functions other than locomotion.

An experimental study to evaluate the performance of variable-width channel cold plates for cooling rectangular Li-ion batteries

The limited cooling capacity of cold plates employing conventional channel designs represents a key obstacle in thermal management systems. The persistent growth of the thermal boundary layer and the uneven distribution of flow across the channels are the principal challenges encountered in this context. To overcome these challenges, this study aims to analyse a modified cold plate of obstructed variable-width channels that can improve the hydrothermal performance and temperature uniformity. Different shapes of pin fins and grooves with variable sizes that match the width of the variable-width channels are proposed. Specifically, four types of pin fins–grooves were used: ellipse, drop, rhombus and trapezoid. The traditional cold plate served as a basis for evaluating the performance of new designs of cold plates. In addition to the traditional cold plate, the four proposed designs of cold plates were manufactured from copper. Experiments were conducted with water as a working fluid under a laminar flow for a flow rate range of 0.004–0.04 kg s-1 and a discharge C-rate range of 1C–2C. Results indicated that the use of variable-width channels with all shapes of fins–grooves effectively contributed to improving the heat dissipation of the cold plate, accompanied with an increase in hydraulic pumping power. At the highest flow rate, the best improvement percentage in the Nusselt number of 82.5 % was achieved when trapezoidal pin fins–grooves were used; by contrast, the lowest pumping power increasing percentage of 33.2 % was obtained when elliptical pin fins–grooves were adopted. The best hydraulic/thermal performance was achieved when trapezoidal pin fins were utilised, with the highest figure of merit of 1.685.

Application of LED Bulb with Perforated Plus Shape Fin Array in Mines

This paper works on design and developments of cooling system of LED. This work particularly studies on the passive cooling system of a 50W street-light lamp made by multiple LEDs. For analysis purposes, different parameters are considered such as: Density, kinematic viscosity, velocity, junction temperature, heat transfer rate, laminar flow and heat transfer modes. The findings suggest that using plus shape fins with a 1 mm diameter drill can enhance convection heat transfer, resulting in a 21.8% increase in surface area. Additionally, the "Plus" shape of the fins facilitates the formation of an air swirl, contributing to a 30.41% decrease in heat sink temperature. Furthermore, material porosity enhances cooling rates by generating swirls and promoting upward airflow. Ultimately, Plus shape fins emerge as an optimal solution for passive cooling systems, mimicking the efficiency of active cooling systems. The cooling model, proposed along with different shapes and weights of materials having specially designed fins porous materials, is unique so far in our knowledge.

A Review on Heat Transfer Enhancement in a Heat Exchanger

Compact heat exchanger is commonly used in car radiators which is normally small with low flowrate. To produce a large surface area, thin plates or corrugated fins are attached closely separating the two fluids. Compact heat exchanger is normally used in applications where weight and volume are the significant factors for the enhancement of heat transfer. This paper reviews the research related to the characteristics, advantages and findings on various type of compact heat exchanger. It is found that the geometric parameters such as fin shape, tube shape, fin pitch, tube pitch, tube arrangement, tube angle and vortex generators affect the heat transfer performance in general. The air inlet angle of 45° and common flow upstream gives the optimum heat enhancement in most studies while the most suitable air flow is between 1.8 – 3.8 m/s.

Numerical analysis of the combined influence of fin shape and location on constrained melting of phase change materials in a spherical capsule with double fins

AbstractThis study presents a novel approach to investigating the combined influence of fin position and shape on the constrained melting behavior of phase change material (PCM) within a spherical capsule (S.C.) through numerical analysis. Unlike previous research, which predominantly focused on single fin shapes or positions, this work uniquely explores the impact of double, simple, and easily manufacturable fin shapes. A two‐dimensional computational model employing the enthalpy–porosity method assesses melting behavior, temperature distribution, and PCM flow. Numerous fin shapes, namely rectangular, trapezoidal converging, trapezoidal diverging stepped, inverse stepped, and triangular, are considered in the analysis. The study reports the influence of the location of two identically shaped fins on the thermal performance. The fins' cross‐sectional area and base thickness are kept equal in all cases. The thermal performance of an S.C.‐integrated fin system is evaluated by analyzing various attributes such as total saving in the duration of melting, enhancement ratio, and Nusselt number. The results indicate that the position of the fins has a more significant impact on melting performance than the fin shape. The best performance is achieved when fins are placed in the lower half of the capsule, followed by the center and upper halves, regardless of fin shape. For rectangular fins, shifting the position of the fin from the bottom half to the center increases the melting time by 24.7% and the top half by 68.3%. The shortest melting time of 93 min is observed for lower‐half rectangular fins, followed by center‐placed triangular fins (94 min). This study offers a theoretical foundation for optimizing the performance of different technologies using latent heat thermal energy storage systems such as packed‐bed, cascaded thermal energy storage systems.

An improved analytical method for rarefied aerothermodynamics on a complex geometry in free-molecular flows

A numerical method for high altitude aerothermodynamic analysis code for Very Low Earth Orbit (VLEO) satellite and spacecraft, named as HACS, is presented in this article. HACS is a computational tool that addresses the challenges by integrating the free-molecular gas kinetic model with novel particle sampling method and robust particle tracing algorithm to predict the shadow region on surfaces. To ensure the reliability and accuracy of the HACS, a rigorous verification and validation process has been systematically conducted by comparing the aerothermodynamic properties of forces, moments, and heat flux with the direct simulation Monte-Carlo (DSMC) results. The HACS is applied to the realistic geometries of VLEO satellite, the Apollo re-entry module, and spacecraft including fin and wing shapes. Results demonstrate that HACS provides the aerothermodynamic properties within the time frame of 60 seconds for the complex geometries and the accuracy of the HACS is guaranteed above 120 km altitude. The maximum relative error of the aerothermodynamic properties is less than 5% compared to the DSMC results at the lowest altitude of about 120 km, and has smaller relative errors as the altitude increases.

Performance analysis of minichannel heat sink with oblong cavities and diverse pin fin configurations

AbstractPassive heat transfer techniques in minichannel heat sinks (MCHS) provide effective thermal management solutions for high heat flux applications. The current study introduces a three‐dimensional numerical analysis conducted to explore the flow and heat transfer characteristics of MCHS utilizing two passive techniques: incorporating pin fins with oblong‐shaped cavities. Four types of pin fin shapes were developed, including tear‐drop (MCOC‐TDPF), pyramidal (MCOC‐PPF), conical (MCOC‐CPF), and oval (MCOC‐OPF), respectively. The study is carried out under a laminar flow regime with Reynolds number ranging from 100 to 1000. The overall performance of these designs is assessed through a comparative analysis of traditional MCHS based on average Nusselt number, friction factor, and overall performance factor. Among these designs, MCOC‐CPF exhibited superior thermal performance compared to the other three configurations, with a maximum performance factor of 2.25 at a Reynolds number of 1000. Furthermore, the influence of conical pin fin taper ratio (β) on the thermal enhancement of MCOC‐CPF is also analyzed. Four values of conical pin fin taper ratio (β) have been considered, namely 1/6, 1/3, 1/2, and 2/3. The results revealed that β = 1/3 achieved an optimal overall performance of 2.39 at Reynolds number Re = 1000.

Optimization of heat transfer in PCM based triple tube heat exchanger using multitudinous fins and eccentric tube

This study aims to analyze the effect of incorporating a hybrid concept of heat transfer enhancement using extended surfaces and eccentricity of the inner tube in an RT-82 phase change material-based horizontal triple tube heat exchanger. Three types of fins were used, namely longitudinal, arc and triangular shape fins, as per suitability for better heat transfer. Moreover, the concept of eccentricity was also implemented to make PCM melt faster. The novelty of the present study lies in optimizing the heat transfer enhancement by proper placement of the fins and eccentric inner tube arrangement. A conduction-convection model was used to examine the thermal performance of a triple tube heat exchanger. The natural convection of PCM was employed using the Boussinesq approximation. The governing equations were solved using finite volume-based Ansys Fluent 2021 R2 software. The performance study of phase change material was based on transient variation of liquid fraction and average temperature. The optimum model showed a 63.87 % reduction in melting time and a 175.16 % improvement in heat transfer rate compared to a simple triple tube heat exchanger to achieve the unit liquid fraction. It is also observed from the calculation of the Rayleigh number that the conduction became more dominant than the convection phenomenon in the fin based model. The main finding of the present study is the use of triangular fins on the base along with the curved fins at the lower middle section because this arrangement shows high heat penetration capability. The results indicate that fins selection and placement significantly enhance the heat transfer rate.

Double pass solar air heater with aerofoil and bio-inspired fins: A numerical analysis of thermohydraulic performance

In the present study, a numerical flow analysis is performed on a double pass solar air heater (DPSAH) with a bottom plate surface roughened using aerofoil fins to study its thermohydraulic performance. The experimentally validated DPSAH model was studied considering factors like different fin shapes, diurnal variation of solar radiation, absorber plate material, and the flow conditions at different relative height ratios (h/H) between 0.17 and 0.50 and fin length ratio (l/H) of 0.29. Using the RNG k-ε turbulence model, the relative Nusselt number (Nu/Nus), relative friction factor (f/fs), and thermohydraulic performance factor (THPF) were found for Reynolds number between 3000 and 21000 with an increment of 3000. The maximum enhancements of 4.23 and 2.51 times were achieved in the Nu/Nus and THPF values, respectively, for a Re value of 3000 in a 2-row setup with h/H of 0.50. The DPSAH with bio-inspired fins performed better than optimized aerofoil fins for majority of the tested range even with similar increase in effective heat transfer area. The values predicted using correlations developed in this study and numerically obtained values of the Nusselt number and friction factor matched closely with an extreme deviation of 5 % in f values.

Development of a Vertical Submerging and Emerging Bat-Ray-Inspired Underwater Vehicle.

In this article, the development of a bat-ray-inspired underwater vehicle is presented; although the propulsion of the vehicle is based on traditional thrusters, the shape of the ray's fins was used as a model to design the body of the vehicle; this architecture allows the independent control of the forward velocity and the full attitude of the vehicle using only two thrusters and two articulated fins. The compact design of the robot, along with the high dexterity of the architecture, allows the vehicle to submerge and emerge vertically as well as navigate horizontally. The mathematical model of the proposed vehicle, including dynamics and propulsion system, is presented and validated using numerical simulations. Finally, experimental tests are presented to demonstrate the capabilities of the proposed design.

Hybrid artificial neural networks-based approaches predicting the heat transfer and flow characteristics of manifold microchannels

Aiming at meeting the requirement of high heat flux electronics cooling, the geometric complexity of manifold microchannels as an energy-saving technique has been increasing rapidly. It is well worth exploring optimal prediction models for the heat transfer and flow characteristics of manifold microchannels to reduce computing resources and time costs in the optimization process. In this paper, hybrid prediction approaches based on artificial neural networks are proposed for manifold microchannels. Four optimization algorithms, namely, genetic algorithm, particle swarm optimization algorithm, artificial hummingbird algorithm, and zebra optimization algorithm were adopted to enhance the prediction performance. Initially, all prediction models were trained and tested by a numerical database including six input parameters, and the thermal resistance and pumping power were taken as the target outputs. Compared to the original method, hybrid prediction models show higher accuracy and reliability on the numerical data with regression coefficients beyond 0.987. The prediction model optimized by the artificial hummingbird algorithm shows the best performance with the mean average error for thermal resistance and pumping power decreased by 88.7% and 81.4% respectively. Additionally, the runtime of all prediction models is compared and the model optimized by the zebra optimization algorithm takes the longest time, but is still two orders of magnitude shorter than that of the traditional simulation method. Finally, the generalizability of all prediction models is further validated by a database amassed from six experimental studies on manifold microchannels. The results showed that three hybrid models can provide accurate outputs with regression coefficients beyond 0.84 which differs from the poor prediction of the original method. The model optimized by the zebra optimization algorithm shows superior prediction performance for six individual studies, two fluids, three fin shapes, and wide flow rate conditions. The trained hybrid prediction models in this study perform higher accuracy and can be cost-effective and reliable prediction tools for the rapid optimization process of various manifold microchannel applications.

Contrasting macroevolutionary patterns in pelagic tetrapods across the Triassic-Jurassic transition.

The iconic marine raptorial predators Ichthyosauria and Eosauropterygia co-existed in the same ecosystems throughout most of the Mesozoic Era, facing similar evolutionary pressures and environmental perturbations. Both groups seemingly went through a massive macroevolutionary bottleneck across the Triassic-Jurassic (T/J) transition that greatly reduced their morphological diversity, leaving pelagic lineages as the only survivors. However, analyses of marine reptile disparity across the T/J transition have usually employed coarse morphological and temporal data. We comprehensively compare the evolution of ichthyosaurian and eosauropterygian morphology and body size across the Middle Triassic to Early Jurassic interval and find contrasting macroevolutionary patterns. The ecomorphospace of eosauropterygians predominantly reflects a strong phylogenetic signal, resulting in the clustering of three clades with clearly distinct craniodental phenotypes, suggesting 'leaps' towards novel feeding ecologies. Ichthyosaurian diversification lacks a discernible evolutionary trend, as we find evidence for a wide overlap of craniodental morphologies between Triassic and Early Jurassic forms. The temporal evolution of ecomorphological disparity, fin shape and body size of eosauropterygians and ichthyosaurians during the Late Triassic does not support the hypothesis of an abrupt macroevolutionary bottleneck near the T/J transition. Rather, an important turnover event should be sought earlier, during times of rapid sea level falls.

Exploring cavitation dynamics and noise reduction in hydraulic machinery with bionic leading edge impeller

Cavitation and induced noise are common issues in the operation of mixed-flow pumps, affecting their stability. Studying these phenomena is of both academic and engineering interest. Previous research has mainly focused on modifying the impeller blade profile or optimizing the pump structure to reduce cavitation and noise. In this paper, we apply a bionic design to the mixed-flow pump impeller by mimicking the natural shape of a humpback whale's pectoral fin on the leading edge of the blade. We compare the cavitation suppression and noise reduction effects of this design with those of a conventional mixed-flow pump. Unsteady flow calculations for the original pump at different flow rates revealed that at its rated speed, increasing flow rates led to lower pressure in the low-pressure region on the suction surface of the impeller, expanding the cavitation-prone area. By applying the bionic design, we studied the unsteady cavitation flow and its induced noise. Results showed that the impeller and guide vane experienced larger pressure pulsations at the rotation frequency and its multiples. The bionic modification increased the cavitation initiation speed and reduced the cavity volume within the runner. With an NPSH (net positive suction head) of 6.76, the void volume in the bionic pump was only 79% of that in the original pump, and the head increased by 16%. Additionally, the bionic design reduced the maximum far-field sound pressure level by 12.5%, achieving significant noise reduction. This study demonstrates that the bionic design effectively controls dynamic flow separation, reduces flow-induced noise, and enhances the mixed-flow pump's performance. These findings have important theoretical and practical implications for optimizing mixed-flow pump design, improving energy efficiency, and reducing noise.

Characteristics of Morphological Changes in Fins according to Larval Growth of Red Spotted Grouper, Epinephelus akaara.

This study investigated the fin development and morphological characteristics according to larval growth in order to obtain information on behavioral characteristics and optimal stocking density during red seed grouper seed production. To examine the growth and fin development process of the larvae, we randomly sampled at 1, 3, 5, 7, 9, 10, 11, 13, 15, 17, 19, 20, 25, 30, 39, 45, 51, and 72 days after hatching. External morphology was observed and measured using an optical microscope. To observe skeletal development, larvae at 13, 20, 30, and 72 days after hatching were fixed in formalin and stained for cartilage and bone examination. At 9-10 DAH, red spotted grouper larvae (2.74±0.1 to 3.0±0.2 mm TL) exhibited a second dorsal fin spine and pelvic fin spine, which subsequently elongated. At 19-20 DAH, the larvae (5.7±0.1 to 6.1±0.1 mm TL) have the lengths of the second dorsal fin spine and pelvic fin spine average 34% and 31% to total length, respectively. From 30 to 72 DAH (12.6±0.4 to 56.0±0.2 mm TL), the length of the second dorsal fin spine and pelvic fin spine to total length decreased from 27% to 8% for the dorsal fin and 21% to 14% for the pelvic fin, respectively. At 30 DAH (12.6±0.4 mm TL), the larvae reached the complete count of fin rays in each fin. At 39 DAH (20.28±3.07 mm TL), the larvae had fin shapes similar to those of adults. At 13-30 DAH (4.2±0.1 to 12.6±0.9 mm TL), barbs and spinules were distributed along the ridges of the second dorsal and pelvic fin spines. However, at 72 DAH, these barbs and spinules were no longer observed on the fins. During the seed production process, red spotted grouper larvae tend to cluster in the morning, and during this time, entanglement of barbs and spinules on the second dorsal and pelvic fin spines can lead to mortality. Therefore, it is considered essential to focus on managing the behavioral patterns and appropriate rearing density of red spotted grouper larvae from the emergence of barbs and spinules on the second dorsal and pelvic fin spines until they regress and metamorphosis is completed.

Multi-objective optimization of L-shaped fins in rectangular phase change energy storage units based on genetic algorithm

Phase change energy storage technology holds immense potential in the field of energy storage, and enhancing the efficiency of energy storage systems has long been a focal point of industry attention. This study aims to optimize the design of an L-shaped fin structure to improve the melting rate of the phase change material (PCM) within a rectangular phase change energy storage unit and enhance the overall system performance. Through the utilization of numerical simulations and the response surface method (RSM), the influence of fin design parameters - specifically, the length and thickness of the main segment and the length and thickness of the branch segment - on the energy storage per unit mass (Em) and energy storage efficiency (Pt) of the energy storage unit is evaluated. The results reveal that the length of both the main and branch segments of the L-shaped fin significantly impacts the melting rate of the PCM, whereas the thickness of these segments has a comparatively lesser effect. Additionally, when the length of the main segment reaches a sufficient value, increasing the length of the branch segment effectively addresses the challenge of PCM melting difficulties at the bottom of the rectangular phase change cavity caused by natural convection. The Non-Dominated Sorting Genetic Algorithm-II (NSGA-II) is employed for the multi-objective optimization of the L-shaped fin shape, and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) with entropy weighting is applied for decision-making to determine the optimal solution. Notably, when the weights of Em and Pt are set at 44.9 % and 55.1 % respectively, the overall performance of the energy storage unit is optimized. The Pareto-optimal decision solution exhibits a significant improvement of nearly threefold in Pt compared to the case without fins, while the reduction in Em is only 5.24 %. This design approach presents a novel perspective for determining fin parameters in phase change energy storage devices and is expected to drive advancements in phase change energy storage technology.

Effect of Shape and Placement of Twisted Pin Fins in a Rectangular Channel on Thermo-Hydraulic Performance

Effect of Shape and Placement of Twisted Pin Fins in a Rectangular Channel on Thermo-Hydraulic Performance