Optimal Heat Transfer Research Articles

Exploring the combined influence of primary and secondary vortex flows on heat transfer enhancement and friction factor in a dimpled configuration twisted tape with double pipe heat exchanger using SiO2 nano fluid

The double-pipe heat exchanger has a wider application in food industries, chemical industries, and a wide variety of fields where heat transmission is necessary. This investigation focuses on optimizing heat transfer rates through active, passive, and combined approaches. Within the realm of passive methods, this study specifically examines the use of twisted tape additions in pipe flow. In this study, different factors like swirl flow, primary and secondary vortex flows caused by tape twist, and the presence of a V-cut on the tape are studied. These factors include heat transfer rate, friction factor, and the standard for judging the performance of a V-cut on the tape insert. Experiments have been conducted on a double-pipe heat exchanger with nanofluid silicon dioxide as the working medium. This study encompasses a Reynolds number range of 6000–14,000. Notably, investigations reveal that the introduction of a v-cut on the tape engenders a secondary vortex flow. The enhancement in the Nusselt number at the higher Reynolds number for the primary vortex was observed ineffective as the depth of cut increases. The friction factor is increased by 6.37 times for the e/c ratio, which equals 0.17 (tooth to the depth of the v cut) in comparison to smooth pipe, while the increase in heat transfer rate for the same is 87.73% for Re = 6000.

Designing & Developing a Porous based Box-Type Heat Exchanger for Enhanced Heat Transfer Rate

Abstract: The shell-and-tube heat exchanger's geometric configuration is optimized during the design development phase by taking into account various aspects like baffle spacing, tube arrangement, and overall system integration. Incorporating a blower into the system results in improved air circulation and effective heat transfer. By placing the band heater in a strategic location, air is heated precisely and locally, which helps to create a more responsive and controlled heating process. One essential tool for assessing the system's thermal and fluid dynamics is CFD analysis. The heat exchanger, blower, and band heater components' fluid flow patterns, temperature distributions, and pressure gradients are investigated through simulations. The CFD analysis provides valuable insights that guide design modifications aimed at optimizing heat transfer rates, minimizing pressure drops, and improving the integrated system's overall performance

Fabricating a Structured Single‐Atom Catalyst via High‐Resolution Photopolymerization 3D Printing

AbstractThis study introduces a novel solution to the design of structured catalysts, integrating single‐piece 3D printing with single‐atom catalysis. Structured catalysts are widely employed in industrial processes, as they provide optimal mass and heat transfer, leading to a more efficient use of catalytic materials. They are conventionally prepared using ceramic or metallic bodies, which are then washcoated and impregnated with catalytically active layers. However, this approach may lead to adhesion issues of the latter. By employing photopolymerization printing, a stable and active single‐atom catalyst is directly shaped into a stand‐alone, single‐piece structured material. The battery of characterization methods employed in the present study confirms the uniform distribution of catalytically active species and the structural integrity of the material. Computational fluid dynamics simulations are applied to demonstrate enhanced momentum transfer and light distribution within the structured body. The materials are finally evaluated in the continuous‐flow photocatalytic oxidation of benzyl alcohol to benzaldehyde, a relevant reaction to prepare biomass‐derived building blocks. The innovative approach reported herein to manufacture a structured single‐atom catalyst circumvents the complexities of traditional synthetic methods, offering scalability and efficiency improvements, and highlights the transformative role of 3D printing in catalysis engineering to revolutionize catalysts’ design.

Multi-Objective Topology Optimization of Conjugate Heat Transfer Using Level Sets and Anisotropic Mesh Adaptation

This study proposes a new computational framework for the multi-objective topology optimization of conjugate heat transfer systems using a continuous adjoint approach. It relies on a monolithic solver for the coupled steady-state Navier–Stokes and heat equations, which combines finite elements stabilized by the variational multi-scale method, level set representations of the fluid–solid interfaces and immersed modeling of heterogeneous materials (fluid–solid) to ensure that the proper amount of heat is exchanged to the ambient fluid by solid objects in arbitrary geometry. At each optimization iteration, anisotropic mesh adaptation is applied in near-wall regions automatically captured by the level set. This considerably cuts the computational effort associated with calling the finite element solver, in comparison to traditional topology optimization algorithms operating on isotropic grids with a comparable refinement level. Given that we operate within the constraint of a specified number of nodes in the mesh, this allows not only to improve the accuracy of interface representation and motion but also to retain the high fidelity of the numerical solutions at the grid points just adjacent to the interface. Finally, the remeshing and resolution steps both run within a highly parallel environment, which makes it possible for the proposed algorithm to tackle large-scale problems in three dimensions with several tens of millions of state degrees of freedom. The developed solver is validated first by minimizing dissipation in a flow splitter device, for which the method delivers relevant optimal designs over a wide range of volume constraints and flow rate distributions over the multiple outlet orifices but yields better accuracy compared to reference data from literature obtained using uniform meshes (in the sense that the layouts are more smooth, and the solutions are better resolved). The scheme is then applied to a two-dimensional heat transfer problem, using bi-objective cost functionals combining flow resistance and thermal recoverable power. A comprehensive parametric study reveals a complex arrangement of optimal solutions on the Pareto front, with multiple branches of symmetric and asymmetric designs, some of them previously unreported. Finally, the algorithmic developments are substantiated with several three-dimensional numerical examples tackled under fixed weights for heat transfer and flow resistance, for which we show that the optimal layouts computed at low Reynolds number, that are intrinsically relevant to a broad range of microfluidic application, can also serve as smooth solutions to high-Reynolds-number engineering problems of practical interest.

Prediction and Optimization of Heat Transfer Performance of Premixed Methane Impinging Flame Jet Using the Kriging Model and Genetic Algorithm

In practical applications, rapid prediction and optimization of heat transfer performance are essential for premixed methane impinging flame jets (PMIFJs). This study uses computational fluid dynamics (CFD) combined with a methane detailed chemical reaction mechanism (GRI–Mech 3.0) to study the equivalence ratio (ϕ), Reynolds number (Re) of the mixture, and the normalized nozzle–to–plate distance (H/d) on the heat transfer performance of PMIFJs. Moreover, the Kriging model (KM) was used to construct a prediction model of PMIFJ heat transfer performance. A genetic algorithm (GA) was used to determine the maximum likelihood function (MLE) of the model parameters for constructing KM and identify the points with the maximum root mean square error (RMSE) as the new infilled points for surrogate–based optimization (SBO). Combining these methods to analyze the simulation results, the results show that the global heat transfer performance of PMIFJs is enhanced with the increase in ϕ, the increase in Re, and the decrease in H/d. Sensitivity analysis points out that Re and ϕ significantly affect enhanced heat transfer, while H/d has a relatively small effect. In addition, GA was also used to search for the optimal heat transfer performance, and the global heat transfer performance at specific conditions was significantly enhanced. This study deepens the understanding of the heat transfer mechanism of impinging flame jets and provides an efficient method framework for practical applications.

Exploring the complex interplay of factors in convective heat transfer: a comprehensive parametric analysis in three-dimensional permeable cavities

ABSTRACT This examination aimed to mathematically investigate the blended convective intensity movement inside a three-layered nook that consolidates a spinning roundabout chamber and an undulating permeable pit. Using the limited component technique (FEM), mathematical reproductions were executed across different boundaries, enveloping the Darcy number going from 10 − 5 to 10 − 2 Hartmann number (going from 0 to 100, the angular velocity between − 4000 and 4000, and the number of undulations in the permeable pit. The results, addressed through stream capability, isotherms, and isentropic forms, clarify the effect of these boundaries on movement, heat transport, and entropy age. The ends suggest that for an ideal upgrade of intensity move rates in a three-layered undulating permeable cavity with a pivoting chamber and exposed to an attractive field, explicit circumstances are suggested, a Darcy number more prominent than or equivalent to 10 − 2 , a Hartmann number of 0, undulation of the permeable pit (N = 3), and angular velocity surpassing 2000 in the stream heading. The study investigates convective heat transfer in a rotating cylindrical chamber, analyzing parameters like Darcy number, Hartmann number, and rotation speed for optimizing heat transfer systems in complex porous cavities. The optimal heat transfer occurs when the aspect ratio is fixed at 0.3 and porous media occupies 90% of the channel. A 150% enhancement in the Nusselt number can be observed when the cylinder’s rotational speed increases. The study also found that increasing angular velocity and Darcy number positively affects the Nusselt number. The research aims to understand the interplay of factors affecting convective heat transfer and fluid dynamics and offer practical implications for optimizing heat transfer systems. The novelty of this study lies in its thorough examination of convective heat transfer in a rotating cylinder-shaped porous cavity, focusing on factors like Darcy number, Hartmann number, rotation speed, and pit geometry. It provides insights for optimizing heat transfer efficiency in complex cavities and explores the impact of external magnetic fields and fluid dynamics. The study investigates the influence of parameters like Hartmann number, angular speed, and Darcy number on thermal and flow characteristics in a porous cavity filled with Fe3O4/MWCNT-water nanofluid, highlighting their importance for optimizing heat transfer efficiency.

Lie group analysis on EMHD Jeffrey nanofluid flow with exponential heat source: Heat transfer optimization using RSM

The present research examines the behavior of a Jeffrey nanofluid flow across a stretching sheet under the effect of electric and magnetic fields. It comprises the Buongiorno model as well as an exponential heat source. The impact of chemical reaction has also been taken into consideration. While assuming no mass flux, the study considers boundary conditions for thermal convection and velocity slip. Lie group transformations are employed to transform the set of governing equations into a dimensionless system and later simulated using the finite difference scheme. It is found that the velocity profile rises as the Deborah number is enhanced whereas the ratio of relaxation to retardation time parameter has an inverse effect on the velocity profile. It is noted that per unit change in the Deborah number descends the drag coefficient by 31.29%. In this study, the response surface methodology and sensitivity analysis have been conducted by choosing heat transport as the dependent variable and the electric-field parameter ( 0.01 ≤ E ≤ 0.03 ) , exponential heat source parameter ( 0.02 ≤ Qe ≤ 0.06 ) , and Biot number ( 0.15 ≤ Bi ≤ 0.25 ) as the independent variables. The Nusselt number escalates when the Bi number is increased and drops as the E values are raised. In the instance of the Biot number, the Nusselt number exhibits the maximum sensitivity.

Optimizing heat transfer rate with sensitivity analysis on nonlinear radiative hydromagnetic hybrid nanofluid flow considering catalytic effects and slip condition: Hamilton–Crosser and Yamada–Ota modelling

AbstractIn current investigation the optimization of heat transportation rate in a nonlinear radiative buoyancy‐driven hydromagnetic carbon nanotube (CNT) hybrid nanofluid flow is analysed. The proposed catalytic effects and slip condition is accounted for the real‐world complexities of the system. The Hamilton–Crosser (HC) and Yamada–Ota (YO) models are employed to characterize the behaviour of the nanofluid. The primary objective is to enhance the heat transmission rate, which is crucial for various engineering applications such as thermal management, energy systems and so forth. To achieve this, sensitivity analysis is performed to identify the most influential parameters affecting heat transfer in the system. By understanding the sensitivity of these parameters, the performance of the system can be improvised. The study focuses on the interplay between key factors including radiative heat transfer, buoyancy‐driven flow, magnetic field influence, catalytic effects, and slip condition. The presence of CNTs in the nanofluid adds another dimension to the complexity of the system that explores the effects of varying the concentration and size of CNTs on the heat transfer rate. By utilizing advanced mathematical modelling and numerical simulations, the performance of the system under different scenarios and identify the optimal conditions for maximizing heat transfer rate is evaluated. The findings of this research provide valuable insights into the design and optimization of heat transfer systems involving nanofluids with nonlinear radiative and hydromagnetic effects. The observation shows that, irrespective to single wall and multi wall CNT nanoparticles the fluid velocity attenuates significantly whereas it favours in enhancing the fluid temperature. Further, the comparative analysis reveals that the heat transfer augments in the case of HC model than that of YO model.

Experimental studies on the effect of Al2O3 + water nanofluid concentrations on dimensionless heat transfer parameters in a cleanroom air handling unit

Nanofluid, a colloidal suspension of nonmetallic or metallic nanoparticles into conventional base fluid and used for heat transfer characteristics enhancement for many industrial applications. Cleanrooms are essential at various industries for controlling airborne contamination and environmental parameters. In this article, heat transfer properties of nanofluid (Al2O3 + water) at various nanoparticle concentrations (1%, 2%, and 3%) on a prototype cleanroom air handling chiller unit was investigated experimentally in laminar flow zone. Thermal conductivity ratio, Nusselt number, Peclet number, and pressure drop were obtained for above nanoparticle concentrations. Experimental investigations indicate the heat transfer properties improvement in a prototype cleanroom air handling chiller unit by using nanoparticle at base fluid. Experimental investigation on varying Al2O3 + water nanofluid concentrations in a cleanroom air handling chiller unit heat exchanger revealed a notable increase in heat transfer by reducing nanoparticle size from 50 to 10 nm and increasing concentration from 1% to 3% volume, resulting in a 17.70% rise in thermal conductivity ratio and a significant 9.23% increase in Nusselt number at higher Peclet numbers. However, this improvement in heat transfer was accompanied by a substantial 72.5% increase in pressure drops, particularly with increased Reynolds number and particle concentration. Manipulating nanoparticle characteristics resulted in substantial improvements in Nusselt number across a wide range of Reynolds numbers, with smaller particle sizes and higher volume concentrations yielding more significant heat transfer improvements. The novelty of this research lies in its investigation of the influence of variable Al2O3 + water nanofluid concentrations, encompassing different nanoparticle sizes, and volume concentrations, on dimensionless heat transfer parameters within a cleanroom air handling unit, offering valuable insights into optimizing heat transfer efficiency in a controlled and critical environment, addressing a significant research gap in the field.

Hybrid nanofluids flow over a Riga plate surrounded by a variable porous medium for heat transfer optimization

Enhancing the heat transfer rate in hybrid nanofluids is significantly aided by a porous medium. The nanofluid’s heat transfer to the surrounding medium is more efficient due to the presence of a porous medium. The porous space also provides additional surface contact points for heat exchange and an intricate network of interconnected pores. This article elaborates on the incorporation of single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) into water to perform hybrid nanofluids. The flow is considered over a Riga plate surrounded by a variable porous space. Various applications, including thermal management systems, microelectronics cooling, and energy conversion devices, benefit greatly from the study of hybrid nanofluid flow on a Riga plate. The similarity equations of the flow problem are easily tackled with the homotopy analysis method (HAM) built on fundamental homotopy mapping. Furthermore, with the increments in paramount parameters, the skin friction coefficient and heat transfer rate are remarkably meliorated under a higher modified Hartmann number. All reverberations are illustrated in graphs and Tables. From the obtained results it is observed that flow control capabilities are enabled by the variations in permeability in the case of hybrid nanofluids. It is also observed that hybrid nanofluids are more capable to enhance the thermal capabilities of the traditional fluids as compared to the mano nanofluids.

Study on the criterion of the onset of heat transfer deterioration for supercritical CO2 in upward flow

Supercritical fluid heat transfer deterioration (HTD) tends to lower the heat transfer capacity and should be avoided in designing and optimizing heat transfer equipment. It is essential to establish accurate criteria for predicting the onset of HTD. In this study, an experimental investigation of supercritical CO2 in a heated tube with diameters of 8 and 14.5 mm was conducted. By integrating the data obtained from this experiment with experimental data from the published literature, a large dataset covering a wide range of parameters was constructed. Eleven HTD criteria that are only applicable to other fluids and ten HTD criteria that can be applied to supercritical CO2 were compared and evaluated with the experimental dataset. Results show that most of the correlations established for other fluids cannot be directly adapted to CO2. The criteria that only consider mass flux are not accurate for predicting the onset of HTD. With a detailed analysis of the influence pattern of each system parameter on HTD, a new criterion incorporating multiple influencing factors was established. Excellent prediction accuracy of the new criterion was observed from the validation with the experimental dataset.

Convective heat transport in a porous wavy enclosure: Nonuniform multi-frequency heating with hybrid nanofluid and magnetic field

This work investigates the dynamics of the hybrid nanofluidic convective heat transfer in a permeable thermal system under the influence of multifrequency heating and a magnetic field. The geometry comprises a wavy-walled cavity filled with a water-based hybrid nanoliquid (Al2O3–Cu–H2O) in a saturated porous medium. The finite volume approach is applied to scrutinize the hydro-thermal characteristics resulting from bottom heating and side cooling, considering various flow-controlling parameters. The analysis reveals that nonuniform multi-frequency heating can be a highly effective strategy for enhancing heat transfer in complex geometries involving porous systems, nanofluid flow, and magnetic fields. Significant heat transfer improvement is observed at higher frequencies, with an increase of approximately 261.49 % when offset temperatures are introduced. Additionally, an increase in the undulation height of the wavy sidewalls contributes to a partial heat transfer improvement of 13.41 % compared to the case without undulations. The influence of the Darcy number, Hartmann number, porosity index, and nanoparticle concentration on heat transfer performance is also investigated. Higher Darcy and Hartmann numbers result in reduced thermal convection, while increased porosity enhances thermal convection. Elevated nanoparticle concentrations weaken the flow strength due to higher viscosity. System engineers can optimize heat transfer systems in their respective applications by comprehending the interactions between these flow-controlling parameters. This work contributes to a deeper understanding of the hydro-thermal phenomena in a multiphysics problem and provides a foundation for the development of more efficient heat transfer systems.

Simulation of Natural Convection with Sinusoidal Temperature Distribution of Heat Source at the Bottom of an Enclosed Square Cavity.

The lattice Boltzmann method is employed in the current study to simulate the heat transfer characteristics of sinusoidal-temperature-distributed heat sources at the bottom of a square cavity under various conditions, including different amplitudes, phase angles, initial positions, and angular velocities. Additionally, a machine learning-based model is developed to accurately predict the Nusselt number in such a sinusoidal temperature distribution of heat source at the bottom of a square cavity. The results indicate that (1) in the phase angle range from 0 to π, Nu basically shows a decreasing trend with an increase in phase angle. The decline in Nu at an accelerated rate is consistently observed when the phase angle reaches 4π/16. The corresponding Nu decreases as the amplitude increases at the same phase angle. (2) The initial position of the sinusoidal-temperature-distributed heat source Lc significantly impacts the convective heat transfer in the cavity. Moreover, the decline in Nu was further exacerbated when Lc reached 7/16. (3) The optimal overall heat transfer effect was achieved when the angular velocity of the non-uniform heat source reached π. As the angular velocity increases, the local Nu in the square cavity exhibits a gradual and oscillatory decline. Notably, it is observed that Nu at odd multiples of π surpasses that at even multiples of π. Furthermore, the current work integrates LBM with machine learning, enabling the development of a precise and efficient prediction model for simulating Nu under specific operational conditions. This research provides valuable insights into the application of machine learning in the field of heat transfer.

Optimizing heat transfer efficiency with injection in ventilated cavity in the presence of internal thermal effects

Venturing into unexplored territory, the study explores the dynamics of mixed convection flow within a square cavity, influenced by a ventilated channel and an injection port. By conducting numerical simulations, the impact of internal heat generation/absorption and viscous dissipation on heat transfer efficiency is thoroughly examined. Employing a finite difference method alongside an alternate direction implicit scheme and iterative successive under-relaxation (SUR) technique, the study systematically solves the governing equations. The effect of physical parameters, namely the Reynolds number ( 50 ≤ Re ≤ 500 ), Richardson number ( 0.01 ≤ Ri ≤ 10 ), volumetric internal heat generation ( △ * > 0 )/absorption ( △ * < 0 ), Eckert number ( 0 ≤ Ec ≤ 0.3 ), and especially variation of injection strength, on the streamlines, isotherms, and average Nusselt number are discussed graphically. The findings demonstrate a significant improvement in heat transfer efficiency, ranging from 17% to 73% with injection, underscoring its substantial implications for advancing thermal management across diverse engineering domains.

Dynamics of methanol conveying mono and hybrid nanoparticles to optimization of heat transfer across stretching cylinder

This manuscript investigates the comparative analysis of SiC and SiC − Ag with methanol-base fluid. The nano species are more important in many fields such as medicine, catalysis, energy-based research, imaging, and environmental sciences. The present study includes theoretical and numerical studies of the Prandtl hybrid nanofluid flow model, which takes into account the effects of heat radiation across a stretched cylinder, inclined magnetohydrodynamics (MHD), and Darcy-Forchheimer. The cylinder’s surface is subjected to the convective slip boundary condition as part of the study. The main aim of this study is to enhance heat transformation. The flow problem is formulated in a system of nonlinear partial differential equations. By employing a similarity transformation, a nonlinear system of partial differential equations can be converted into a linear system of ODEs. A feasible numerical technique Bvp4c is used to solve the reduced system of ODEs through MATLAB software. The results of temperature, concentration, and velocity profiles are discussed graphically. In section and injection scenarios, the velocity profile of both fluids decreased with increasing inputs of magnetic and Darcy-Forchheimer parameters. The heat transmission improved for higher inputs of Prandtl and thermal radiation parameters for both section and injection cases. Furthermore, our findings align with the body of current literature. The conclusions are supported by a careful comparison with pertinent research that has been published in earlier publications.

A numerical study on nanoparticles shape effects in modulating heat transfer in silver-water nanofluid over a polished rotating disk

Investigations of mechanical and thermodynamic aspects related to flows induced by rotating disks are of paramount importance, given their widespread application in various industrial processes. Keeping this in mind, the present study examines the influences of nanoparticles shape on heat transfer for silver-water nanofluid flow over a polished rotating disk. The nanofluid's viscosity demonstrates dependence upon temperature and nanoparticles volume fraction, considering both the cylindrical and spherical type nanoparticles. The polished disk surface proposes velocity and thermal slip at the interface. The present mathematical model also accounts for heat generation/absorption along with the aforementioned aspects. Reduction in the governing system through 'similarity transformations is carried out. The resulting system of equations are solved numerically using the built-in numerical solver NDSolve in Mathematica. Outcomes reveal that the variations in viscosity due to temperature not only impact skin friction but also the Nusselt number for given flow. Another noteworthy result is that a polished rotating disk demonstrates reduced wear and tear attributed to higher skin friction, which can be further mitigated by enhancing the velocity slip parameter. Notably, this study uncovers different impacts of cylindrical and spherical nanoparticles, advancing the understanding of heat transfer and the mechanics of rotating disc flows. Cylindrical and spherical nanoparticles exhibit distinct behaviors within the flow. This cautions engineers to carefully select nanoparticles geometries to optimize heat transfer performance based on the specific requirements of their applications. Understanding these geometry-dependent effects is essential for designing efficient heat transfer systems.

Mixed convection heat transfer in a partial porous layered split lid-driven wavy wall cavity with Cu–H2O nanofluid

This numerical study investigates mixed convection heat transfer in a two-dimensional irregularly-shaped enclosure with a nanofluid-saturated porous medium. The enclosure has wavy vertical walls, a centered triangular block, and a lid split into two regions moving in opposite directions. Transport equations are solved using the finite element method under varied Darcy (10−5 to 10−1), Reynolds (50 to 200), Richardson (0.1 to 10), amplitude (0 to 0.2), and nanoparticle volume fraction (0 to 0.1) numbers. Results demonstrate the combined effects of forced convection from lid motion and natural convection from temperature differences significantly enhance heat transfer. The wavy walls induce secondary flows and periodic disruption of thermal boundary layers. Increasing Darcy number enables deeper penetration into the porous block. Copper nanoparticles incrementally improve conductive heat transfer. Richardson number effects are more prominent at higher Reynolds numbers as buoyancy forces influence vertical convection. This study provides novel insights into synergistically utilizing wavy geometries, nanofluids, porous media, and active pumping for optimizing heat transfer in irregular enclosures for electronics cooling and thermal management.

Comparative study of nonlinear thermal convection on magnetized dissipative flow along a shrinking Riga sheet with entropy generation

The concept of nonlinear thermal convection is taking place for the process of cooling/heating in some thermal industries like solar collectors, combustion, and reactor safety. The significance of linear and nonlinear thermal convection is implemented in the present mathematical modeling to handle nonlinear density-temperature caused by viscous dissipation and flow through a porous medium. Further, the inclined magnetic field is implemented to analyze the flow characteristic at various inclination angles which will be helpful in glass manufacturing, geophysics, crude oil purification, and paper production. Furthermore, entropy generation analysis is made for the stagnation point flow of viscous fluid over a shrinking Riga sheet. Using boundary layer assumptions, the present model made up of fluid motion and energy equations is formed and converted to a system of nonlinear differential equations. Numerical results are collected using the MATLAB bvp4c solver and these results were utilized to study important parameters on the entropy generation and heat transport of fluid flow. The presence of nonlinear thermal convection will intensify the impact of major parameters and the least entropy generated for the inclination angle of the magnetic field. Also, entropy enhanced significantly with the Eckert number and modified Hartmann number. In addition, the surface drag is enhanced by 12%-18 % and the thermal transmission rate is diminished by 4%-7% in the case of nonlinear thermal convection compared to the linear case. The findings of this study are more important to optimize heat transfer and irreversibility in the applications of the automotive industry, ceramics, paints, food packaging, fabrics, pharmaceuticals, and cancer treatment.

Investigation of heat and mass transfer of oldroyd – 8 constant fluid in wire coating process employing response surface methodology

Wire coating is widely used for electrical insulation, shock protection, preventing leakage, and facilitating smooth current flow. This study aims to evaluate the applicability of Oldroyd-8 constant fluid for wire applications in a magnetic field using a pressure-type die. Based on the Buongiorno model with a constant pressure gradient and temperature-dependent thermophysical properties, governing equations are developed. These equations are transformed into dimensionless form and solved numerically. The study thoroughly investigates key features, including momentum, thermal distribution, nanoparticle volume fraction, and shear stress rate. Also, this study employs Response Surface Methodology to optimize heat transfer and shear stress rates in coated wire. Quadratic models, developed through a central-composite design, determine optimal levels for the Oldroyd-8 constant fluid parameter and nanofluid parameters, ensuring optimal heat transfer and shear stress rates for the melt. Nanofluid parameters contribute to an improvement in the thermal distribution profile. Optimal heat transfer and shear stress rate occur when the nanofluid parameters are minimized, and non – Newtonian fluid parameter is maximized.

Optimizing heat transfer rate and sensitivity analysis of hybrid nanofluid flow over a radiating sheet: Applications in solar-powered charging stations

In a solar collector system, absorbing radiation through solar panel and transforming it into heat, the role of nanofluid is vital. However, the combined effect of CuO and Cu water hybrid nanofluid efficiently carries the fascinated heat away from the solar collector. Further, it helps improve in efficiency of the thermal solar thermal system by enhancing heat transfer and thermal losses. Based upon the advanced properties, the study aims at the behavior of a conducting hybrid nanofluid comprised of CuO and Cu nanoparticles through a nonlinear stretching surface filled with a porous matrix. Essentially, the use of thermal radiation with dissipative heat and convective heat transfer boundary conditions are important in enhancing heat transfer properties. The assemble of diversified similarity rules is useful for the transformation of the governing equations into dimensionless form. Further, numerical technique with the help of built-in function bvp4c in MATLAB is employed for the solution of the designed model equipped with different constraints. A robust statistical analysis i.e. response surface methodology (RSM) combined with analysis of variance (ANOVA) is used to optimize the heat transfer rate. Sensitivity analysis for the associated factors united to the response of heat transfer is obtained and presented briefly. Finally, the parametric behavior is important to describe following the pattern of the graph. Further, the important outcomes are; the enhanced volume fraction of the nanoparticles augments the fluid velocity as well as the temperature significantly. Thermal radiation has influential behavior in enhancing the heat transport phenomenon of hybrid nanofluid.