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In this research, thermal modeling has been done to investigate the effect of nanofluid on the performance of the linear parabolic collector. Therminol vapor/liquid phase fluid (VP-1) has been used as a base fluid; iron oxide nanoparticles have been used to produce mono-nanofluid; and iron oxide multi-walled carbon nanotubes nanocomposite has been used as nanoparticles to produce hybrid nanofluid. The fluid flow inside the absorber tube of the collector is assumed to be turbulent. The results show that when hybrid nanofluid and mono-nanofluid are used, the energy and exergy efficiencies of the collector are higher than those for the conditions of using the base fluid, but their amount is slightly lower with the use of hybrid nanofluid than when the working fluid is mono-nanofluid. According to the obtained results, the highest energy efficiency of the linear parabolic collector using nanofluid and mono-nanofluid is 70.2% and 70.4%, respectively, and the highest exergy efficiency is 35.7% and 35.9%, respectively. Despite this, the friction coefficient of mono-nanofluid compared to hybrid nanofluid was obtained on average about 9% higher. The results showed that the criterion for evaluating the performance of the collector (hydrodynamic thermal efficiency) when hybrid nanofluid is used is more than when mono-nanofluid is used. [ABSTRACT FROM AUTHOR]

The significance of interfacial thermal resistance in the thermal conductivity of nanofluids is not well understood, in part because of the absence of measurements of this quantity. Here, we study the interfacial thermal resistance for metal–oil nanofluids of interest as heat transfer fluids for concentrating solar power, using density functional theory and molecular dynamics simulations. Insights on the role of chemical interactions in determining the interfacial thermal resistance are revealed. The results presented here showcase a general picture in which the stronger the chemical interactions between species at the interface, the lower the associated interfacial thermal resistance. The implications toward nanofluid design are discussed. We show that, for this important family of metal–oil nanofluids, the interfacial thermal resistance values are low enough so that it is possible to afford a reduction in particle size, minimizing stability and rheological issues while still offering enhancement in the effective thermal conductivity with respect to the base fluid. [ABSTRACT FROM AUTHOR]

Fractional calculus expands the idea of differentiation to fractional/non‐integer orders of the derivatives. It includes the memory‐dependent and non‐local system's behaviors while fractal–fractional derivatives is the generalization of fractional‐order derivatives which refers to a combination of fractional calculus and fractal geometry. In this article, we have considered the magnetohydrodynamic (MHD) flow of Casson hybrid nanofluid through a vertical open channel with the effect of viscous dissipation and Newtonian heating. The problem is modeled in terms of non‐linear and coupled integer‐order PDEs which is further generalized through fractal–fractional derivative of power law kernel. Due to non‐linearity and complexities, we have adopted the numerical procedure as it is used when the analytical solutions of PDEs are frequently difficult or impossible for complicated situations. We have established the numerical algorithms for both the classical and fractal–fractional‐order model and compared the results. The existence and uniqueness of the model's solution has been shown theoretically. The effect of various embedded parameters on the heat transfer and fluid flow has been simulated and presented through various figures while skin friction and Nusselt number are tabulated. The effect of fractional and fractal parameter is also shown. As the present model is taken for the hybrid nanofluid flow and for the heat transfer applications, we have considered mineral transformer oil as a base fluid while titania and cadmium telluride nanoparticles are dispersed in it. From the results, it is observed that hybrid nanofluid have a better heat transfer enhancement up to 19.71% while the unitary nanofluids are only capable to enhance the heat transfer up to 9%. [ABSTRACT FROM AUTHOR]

This work gives an insight into the viscous effects of a viscoelastic fluid on the flow and heat transfer when it is put to flow between two nonparallel plates via some source/sink. Modeling of the problem is presented in detail with focus on the viscous dissipation effect. Afterwards, the problem is solved numerically by Keller Box method and bvp4c routine using MATLAB. The comparative analysis of the two techniques has been drawn on the basis of numerical values of Nusselt number. Alongside this, a comprehensive detail of the impact of pertinent parameters on the flow and temperature profiles have been given. The numerical results give an insight about the fluid characteristics like velocity, temperature, heat transfer and skin friction with variations in pertinent physical parameters. [ABSTRACT FROM AUTHOR]

This investigation focuses on the nanoparticle shape effect on the flow of conducting non-Newtonian Maxwell nanoliquid through an absorptive expanding surface. Insertion of inertial drag due to the Darcy–Forchheimer model and the dissipative heat in the flow phenomena supplements the work. The thermal properties of the fluid show its important role because of the use of various thermophysical models such as the Gharesim model of viscosity and the Mintsa model of thermal conductivity. The proposed mathematical model is designed by the implementation of suitable similarity transformations and then a numerical scheme is adopted to solve the transformed phenomena. In particular, shooting-based traditional Runge–Kutta (RK) fourth order is implemented for the solution. The behavior of the parameters that are participating in the flow phenomena is deployed via graphs and the computation of the engineering coefficients is displayed in tables. The impression of innumerable governing flow constraints is interpreted with the validation of these investigations with the earlier investigation. However, the major outcomes are; the particle concentration contributes its significant characteristics in enhancing the fluid velocity as well as temperature for the increasing shape. The dissipative heat formulated by the Eckert number also augments the fluid temperature in association with the thermal radiation whereas the unsteadiness parameter retards it significantly. [ABSTRACT FROM AUTHOR]

This study examines different fluid flow through an elaborated plate. In the modeling of the physical phenomena under investigation, the impacts of viscous dissipation, activation energy and chemical reaction are considered. Also, the heat transport phenomena are explained by the variable thermal conductivity theory. By using the right transformations, the flow-generating PDEs are converted into nonlinear ordinary differential equations. The parameters' impacts on the velocity, temperature and mass fields are analyzed in detail. The modeled problem is graphically handled in MATLAB using the numerical technique (BVP4c). Graphical representations of the important factors affecting temperature and velocity fields are illustrated through graphs. The findings disclose that the effectiveness of the velocity field is determined by the changing values of the magnetic parameter. The Prandtl values are decreased, the temperature profile becomes more pronounced. [ABSTRACT FROM AUTHOR]

Because of accelerated demands of advanced technologies like power station, chemical production and microelectronics, it necessitates the need of novel type of fluids with more heat transfer capability. Due to synergistic effect, ternary composite nanofluids (TCNFs) ensure better thermophysical and Rheology properties thereby acting as better suitable heat transfer fluid in wire coating, metal spinning, aerodynamics, medicine and engineering industries, etc. In view of such relevance, flow and heat transfer aspects of TCNF MWCNT + Al2O3 + TiO2 + water induced by linear and nonlinear slips over arbitrarily inclined moving thin needle are investigated in this study. Thompson and Troian nonlinear slip model is modified by developing it in polar coordinates. Quadratic thermal radiation phenomenon is adopted. Fourth-order Runge–Kutta method is used to obtain requisite numerical solution. Major outcomes indicate that fluid velocity of TCNF whittles down with amplification of magnetic parameter due to the flow induced by either linear or nonlinear slips. Lower value of Reynolds number favoring linear slip leads to effective intensification of nondimensional temperature distributions. Surface viscous drag and heat transfer rate get ameliorated with growth in size of thin needle under the influence of both linear and nonlinear slips. [ABSTRACT FROM AUTHOR]

The effectiveness of jet flow in the energy transfer process has made it very useful in industrial applications. These flows also have higher heat transfer coefficients than traditional cooling through convection. The appliances inclusive of the jet make effective use of fluid and enhance the heat transfer rate. The contemporary article investigates the jet flow of power-law nanofluid past a moving wall. The nanofluid is formed by suspending Cu and Al2O3 nanoparticles in water. Furthermore, the jet flow is analyzed in the presence of radiation, which is further assumed to be linear, and the application of Rosseland approximation is considered to be valid. Considering these aspects, the model is designed using partial differential equations (PDE), which are then converted to a system of non-linear ordinary differential equations (ODE) by implementing certain similarity transformations. Thus, the obtained system is solved using numerical methods, and the results are discussed with the help of graphs. The significant conclusions of the analysis were that the increase in the radiation parameter contributed to the increase in the temperature of the nanofluid. The increase in the Prandtl number reported a decrease in the amount of heat absorbed by the nanofluid. [ABSTRACT FROM AUTHOR]

Purpose: The steady laminar wall jet flow over a stretching/shrinking surface in the presence of lateral suction or injection with a convective boundary condition is considered. Design/methodology/approach: The partial differential equations for mass, momentum and energy conservation are changed to the system of ordinary differential equations through similarity solution transformations. Solutions, both numerical and asymptotic, to these similarity equations are found in some new ranges of parameters in the governing equations. Findings: The equations are solved both asymptotically and numerically for a range of the transpiration parameter S and the flow parameter λ given in Mahros et al. (2023), thus greatly extending the range of these previous solutions. Asymptotic solutions for both large and small values of the Prandtl number σ are derived, showing good agreement with additional numerical integrations. It should be noted that in Mahros et al. (2023), only the case when σ=1 was treated. A solution for large λ when S=1 is obtained, showing a different asymptotic form to the case when S>0 in Mahros et al. (2023). Multiple solutions were seen by them for S<0 and the nature of the lower solution branch as S→0 from below is discussed. The question as to whether the lower branch solutions join as λ>0 when S<0 is resolved through obtaining an asymptotic solution λ small. Originality/value: The accuracy of the solutions has been checked through a detailed comparison between the solutions obtained numerically and analytically, where excellent agreement has been found. This study is important for scientists working in the area of jet flows to become familiar with the flow properties and behaviour of jets. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this article is to present a mathematical model for the fully developed flow of Bi-viscous Bingham nanofluid through a uniform-width anisotropic porous channel. The model incorporates a generalized Brinkman-Darcy formulation for the porous layers while considering the motion of nanoparticles influenced by both Brownian diffusion and thermophoresis effects. Design/methodology/approach: The similarity transformations derived through Lie group analysis are used to reduce the system from nonlinear partial differential equations to nonlinear ordinary differential equations. The finite difference method-based numerical routine bvp4c is employed to collect and graphically present the outcomes for velocity, temperature, and nanoparticle concentration profiles. The flow pattern is analyzed through streamlined plots. Furthermore, skin friction, heat, and mass transmission rates are investigated and presented via line plots. Findings: It is observed that in anisotropic porous media, the temperature profile is stronger than in isotropic porous media. The thermal anisotropic parameter enhances the concentration profile while reducing the temperature. Practical implications: Anisotropy arises in various industrial and natural systems due to factors such as preferred orientation or asymmetric geometry of fibers or grains. Hence, this study has applications in oil extraction processes, certain fibrous and biological materials, geological formations, and dendritic zones formed during the solidification of binary alloys. Originality/value: 1. The permeability and thermal conductivity are not constant; instead, they have different values in the x and y directions. 2. This study considers the dependency of thermophoresis on nanoparticle volume fraction and Brownian diffusion on the temperature in both the fluid flow equations and boundary conditions. 3. A novel similarity transformation is derived using Lie group analysis instead of using an existing transformation already available in the literature. [ABSTRACT FROM AUTHOR]

The study examines the magnetohydrodynamic flow of engineered fluid past an extending cylinder, analyzing the effects of non-linear radiation and an inclined magnetic field. The physical problem generates a system of non-linear coupled partial differential equations, and the system is transformed into ordinary differential equations using similarity transformation and solved using the Runge-Kutta method and shooting technique. Also, sensitivity analysis is taken into account to observe the input variables effects on skin friction and heat transfer rate. The study reveals that magnetic field orientation, nonlinear radiation effects, and injecting more core fluid significantly impact heat transfer characteristics. The effects of angle of orientation, magnetic field, suction parameter, and volume concentration on skin friction are significant. Reynolds number significantly affects heat transfer rate by 62.15% for suction. The findings can be applied in physics and engineering to control heat transfer between stretching surfaces and engineered fluids. [ABSTRACT FROM AUTHOR]

This study aims to compare the dual solutions of the problem describing the magnetized motion of a Newtonian and second‐grade fluid induced by a curved stretching/shrinking surface using the associations of homogeneous–heterogeneous reaction and Cattaneo–Christov model. The model is further developed using the properties of convective heat transfer, suction velocity, Joule heating, heat source/sink, and viscous dissipation with the porous medium. The relevant transformations are applied to the governing partial differential equations (PDEs) resulting in the system of nonlinear ordinary differential equations (ODEs). The solution technique makes use of the computational scheme in MATLAB known as the bvp4c technique. All relevant findings are obtained using a wide range of dimensionless parameters. The Cattaneo–Christov model and the second‐grade fluid transmits heat faster than the classical Fourier law and Newtonian fluid as well as the heat transfer rate of both fluids was found to drop as the values of Eckert number and curvature parameter enhances. Moreover, the Newtonian fluid has lower friction drag than the second‐grade fluid and the concentration of the bulk fluid is declined by the rising values of hetrogeneous and homogeneous reaction parameter. With potential applications in a variety of engineering fields, including thermal management systems and nanofluid‐based technologies, this work is significant for understanding MHD flow of second‐grade nanofluids over curved surfaces, incorporating heterogeneous reactions and the Cattaneo–Christov model. The results also aid in improving heat transfer efficiency and understanding of fluid behavior under various parameter situations, providing information for improving industrial processes and advanced materials engineering design considerations. [ABSTRACT FROM AUTHOR]

In industrial and engineering fields including lamination, melt-spinning, continuous casting, and fiber spinning, the flow caused by a continually moving surface is significant. Therefore, the problem of ternary hybrid nanofluid flow over a moving surface is studied. This study explores the stability and statistical analyses of the magnetohydrodynamics (MHD) forced flow of the ternary hybrid nanofluid with melting heat transfer phenomena. The impacts of viscous dissipation, Joule heating, and thermal radiation are also included in the flow. Different fluids including ternary hybrid nanofluid, hybrid nanofluids, and nanofluids with base fluid ethylene glycol (EG) are examined and compared, where magnetite (Fe3O4) and silica (SiO2) are taken as the magnetic nanomaterials while silver (Ag) is chosen as the nonmagnetic nanomaterial. The skin friction coefficient and the local Nusselt number are estimated through regression analysis. By employing similarity transformations, the governing partial differential equations are converted into non-linear ordinary differential equations. Then, the least square method is applied to solve the equations analytically. Dual solutions are established in a particular range of moving parameter λ. Due to this, a stability test is implemented to find the stable solution by using the bvp4c function in MATLAB software. It is found that the first solution is the stable one while the second is unstable. The use of ternary hybrid nanomaterials improves the heat transport rate. The increasing values of the Eckert number enlarge the heat passage. The fluid velocity and temperature profiles for nonmagnetic nanomaterials are higher than that of magnetic nanomaterials. The uniqueness and originality of this study stems from the fact that, to the best of the authors' knowledge, it is the first to use this combination technique. [ABSTRACT FROM AUTHOR]

The motivation of this paper is to explore an oscillatory flow of a magnetohydrodynamics (MHD) couple stress fluid with heat and mass transfer analyses through a porous medium. The modified Darcy–Brinkman couple stress fluid model is employed. There could be many potential applications of this study, such as thermal system, solidification of liquid crystals, cooling of metallic plates in a bath, exotic lubricants and colloidal solutions. In the wake of these potential applications, the study of MHD couple stress fluid flow with additional diffusing components has been found to be innovative and very interesting in the analysis of the influence of combined magnetic effects, couple stress fluid and two solutes. A governing coupled nonlinear partial differential equation with boundary constraints represents the modeled flow problem. In addition, these equations are converted into nondimensional form by employing the suitable nondimensionalizing quantities. It is possible to attain analytic solutions to the dimensionless equations that control the liquid flow, and the consequences of the flow's confines on velocity, temperature, concentration and skin friction profile are examined and also the results are discussed through graphs. It is noteworthy that when the injection level on the heated plate is increased, the skin friction on each channel plate also increases. [ABSTRACT FROM AUTHOR]

The horizontal ground heat exchanger has been extensively employed to collect geothermal energy from mine backfill bodies. A novel method for avoiding thermal interference using the thermal influencing radius coupling pipe spacing was investigated. Thermal interference between adjacent heat-transfer pipes can be neglected when D40°C=2R40°C is used as the pipe spacing. The comprehensive impacts of heat-transfer fluid and backfill body on the heat-transfer efficiency and thermal influencing radius of the horizontal single pipe were investigated. The growth ratio of heat-transfer capacity can be as high as 227.3% when thermal conductivity increases from 0.5 kJ/(kg·°C) to 2 kJ/(kg·°C). The heat-transfer capacity increases by 4% for every 1°C reduction in inlet temperature. The thermal influencing radius is significantly influenced by specific heat capacity and thermal conductivity. This study can provide theoretical recommendations for the design and improvement of heat-transfer pipes in the backfill body. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to focus on the transient flow and heat transfer of a non-newtonian fluid (Casson fluid) between parallel disks in the presence of an external magnetic field. The bottom disk is considered to be porous and fixed, whereas the upper disk moves down. Also, the influence of the heat source/sink and viscous dissipation is taken into account. The conservative partial differential equations have been transformed into dimensionless ones and are solved semi-analytically using Least Square Method. Besides, applying a numerical solution, the accuracy of analytical results is verified using the fourth-order Runge–Kutta method. The effects of various physical parameters such as suction/injection, heat source/sink, Prandtl number, magnetic field, slip condition, and Casson fluid parameter on velocity and temperature distribution as well as skin-friction coefficient and Nusselt number are examined and discussed. The results have shown that higher values of the Casson fluid parameter decrease the Nusselt number and shear stress. Also, it is observed that the Hartmann number augmentation decreases the heat transfer rate. What is more, it is shown that the intensity of injection/suction affects how streamlines behave against the central vertical axis. [ABSTRACT FROM AUTHOR]

In this paper, we aim at the simulation of setup for vortex generation and measurement. This project will lead to designing the experimental setup to create vortices and development of heat flow sensors. The working fluid for the vortex generator is hybrid nanofluid such as Iron (III) Oxide-MWCNT and propanol. The usage of these hybrid fluids was considered due to their better physical and chemical properties compared to water and other conventional fluids. Ansys Fluent was used to simulate the experiment. Viscosity of the fluid increases for both hybrid nanofluids, from inlet to outlet by a magnitude of 10 times (for Fe3O4 + MWCNT: 5.3 × 10−5 Pa.s to 6.3 × 10−4 Pa.s; for Al2O3 + MWCNT: 7.5 × 10−5 Pa.s to 6.5 × 10−4 Pa.s), for laminar flow (Reynolds number = 400). Vortex generation increases the viscosity of the hybrid mixture but not water (for water, it stays constant across the channel at 4.9 × 10−4 Pa.s). Vortex induced viscosity is seen in hybrid mixtures. Strain thinning due to vortex formation is not observed, therefore the behavior of the mixtures is along the lines of Newtonian fluids. [ABSTRACT FROM AUTHOR]

The comprehensive characterization of AgNO3/graphene nanoparticles, preparation of their hybrid nanofluids and important thermophysical properties investigations have not been done so far to identify their potential application in heat transfer. Hence, current study attempts to characterize AgNO3 and graphene nanoparticles by employing SEM, X-ray diffraction and FT-IR spectrum. Various concentrations of AgNO3–graphene/water hybrid nanofluids (HNFs) are prepared. Two-step preparation process for HNFs involve magnetic stirring followed by probe sonication. Further, HNFs are characterized by particle size analysis and UV-spectroscopy. Additionally, thermal conductivity, specific heat, viscosity and density of HNFs are investigated experimentally with varying temperature ranges 25 °C to 75 °C and concentration ranges 0.01 vol % to 0.03 vol %. AgNO3 and graphene structures peak are obtained at position 2θ = 35.58° and 2θ = 26.42° respectively and both the NPs features slight narrowing peaks. Experimental results reveal that, thermal conductivity improves with increasing temperature and found enhanced by 8.21 % for 0.01 vol %, 15.37 % for 0.02 vol % and 23.59 % for 0.03 vol % concentration at 75 °C compared to water. Specific heat of the HNFs rises with rising temperature whereas at a particular temperature it decreases with increasing NPs concentration. Dynamics viscosity decreases with increasing temperature for all prepared HNFs. The density exhibits no significant variation with the increase in concentration and temperature. Prepared HNFs are recommended as heat transfer fluid in various applications. [ABSTRACT FROM AUTHOR]

Synthetic heat transfer fluids are of immense importance for solar thermal application due to its low vapour pressure, low melting point and high heat capacity. Commonly used synthetic heat transfer fluids are biphenyl and diphenyloxide mixture, imidazolium ionic liquid and terphenyl based chemistry. However these fluids are not found effective above 400 °C operating temperatures as they tend to degrade. As per literature inputs polyaromatic based molecules like 1-phenylnaphthalene (1-PNP) and 2-methy-l-phenylnaphthalene have thermal stability above 400 °C. In the present research work a simple, efficient and environmentally benign procedure of Suzuki coupling is employed for the synthesis of these molecules in the presence of ligand free refinery Pd-spent catalyst in water. The catalyst was found to be recyclable up to 3 times without any loss of efficiency. The synthesized polyaromatic based heat transfer fluid molecules in the presence of radical quencher which indicates their potential for high temperature application. Thermal stability of synthesized polyaromatic based heat transferred fluid was enhanced by free radical quencher. So as to apply the fluid for high temperature usage. [ABSTRACT FROM AUTHOR]

Boiling is a phase change heat transfer process that transfers latent heat quickly, making it suitable for use in various heat transfer systems. An important worry for the boiling performance degradation is the durability of the artificial nano-/microporous interfaces concerning the bottom surface. This study therefore proposes a novel three-step surface creation process (chemical etching, electroplating, and sintering process). Wet/chemical etching is first used to form three distinct micro/nanostructured substrates (ES#1, 2, 3). The most effective etched substrate (ES#3) is again employed as a cathode for the electrochemical depositing process or next-of-surface manufacturing. To strengthen the link between the etched layer (ES#3) and the surface of the coating (copper-alumina), the electroplating produced substrate (ES#4) is sintered in a predetermined environment. The enhanced boiling efficiency obtained on ES#4 is attributable to the appropriate bonding among ES#3 and electroplated nanoparticles (Cu-Al2O3). By maintaining a consistent temperature across the heater's topmost layer and the fin tip, the reduction in resistance at the intermediate level brought on by appropriate binding increases the rate of heat transfer. The critical heat flux (CHF) and heat transfer coefficient (HTC) improvements for ES#4 over bare copper are 184% and 216%, respectively. Additionally, the impact of certain macro- and micro-scale restrictions on the occurrence of flow boiling heat transfer is examined. The ES#4 surface showed better stability during repeated thirty testing cycles, as seen by the much smaller decline in superheat temperatures (1.2 °C) and wettability (32° to 33.7°). [ABSTRACT FROM AUTHOR]

The objective of this article is to study the importance of velocity and thermal slip in the exponentially stretching or shrinking sheet with the megnetohydrodynamic (MHD) hybrid nanofluid flow along with magnetic field, radiative, heat generation effects. This study has practical importance in enhancing heat transfer efficiency, improving energy conversion and optimizing thermal management systems. The findings can also contribute to the development of sustainable energy systems and aid in assessing the stability and safety of nanofluid applications. The governing partial differential equations are transformed into nonlinear ordinary differential equations using similarity transformation. The ODEs are solved using bvp4c solver in MATLAB. The dual solutions are achieved for specific range of the stretching or shrinking parameter and mass suction parameter. The first solution is physically significant after considering stability analysis. The hybrid nanofluid has numerous real‐life and industrial applications, such as microelectronics, manufacturing, naval structures, nuclear system cooling, biomedical, and drug reduction. The skin‐friction increases but Nusselt number decreases over the stretching sheet whereas the opposite effect shows over shrinking sheet for the both solution with the increasing velocity slip parameter. On the other hand, The Nusselt number decreases over the shrinking or stretching sheet for both solutions with the increasing in the thermal slip parameter. The skin friction increases over shrinking sheet but decreases over stretching sheet for the first solution with increasing silver volume fraction parameter and porosity parameter (K$K$). Enhancing magnetic field parameter leads to the skin friction increases over the shrinking sheet but decreases over stretching sheet but Nusselt number shows opposite trend. The Nusselt number decreases over shrinking sheet but increases over stretching sheet for the first solution with increasing porosity parameter (K$K$). The Nusselt number decreases over shrinking or stretching sheet as the increases heat generation (β$\beta$) and variable thermal conductivity parameter (w$w$) but Nusselt number shows opposite trend as the increases radiative parameter (Rd$Rd$). [ABSTRACT FROM AUTHOR]

Concentrated solar power (CSP) has gained traction for generating electricity at high capacity and meeting base-load energy demands in the energy mix market in a cost-effective manner. The linear Fresnel reflector (LFR) is valued for its cost-effectiveness, reduced capital and operational expenses, and limited land impact compared to alternatives such as the parabolic trough collector (PTC). To this end, the aim of this study is to optimize the operational parameters, such as the solar multiple (SM), thermal energy storage (TES), and fossil fuel (FF) backup system, in LFR power plants using molten salt as a heat transfer fluid (HTF). A 50 MW LFR power plant in Duba, Saudi Arabia, serves as a case study, with a Direct Normal Irradiance (DNI) above 2500 kWh/m2. About 600 SM-TES configurations are analyzed with the aim of minimizing the levelized cost of electricity (LCOE). The analysis shows that a solar-only plant can achieve a low LCOE of 11.92 ¢/kWh with a capacity factor (CF) up to 36%, generating around 131 GWh/y. By utilizing a TES system, the SM of 3.5 and a 15 h duration TES provides the optimum integration by increasing the annual energy generation (AEG) to 337 GWh, lowering the LCOE to 9.24 ¢/kWh, and boosting the CF to 86%. The techno-economic optimization reveals the superiority of the LFR with substantial TES over solar-only systems, exhibiting a 300% increase in annual energy output and a 20% reduction in LCOE. Additionally, employing the FF backup system at 64% of the turbine's rated capacity boosts AEG by 17%, accompanied by a 5% LCOE reduction. However, this enhancement comes with a trade-off, involving burning a substantial amount of natural gas (503,429 MMBtu), leading to greenhouse gas emissions totaling 14,185 tonnes CO₂ eq. This comprehensive analysis is a first-of-a-kind study and provides insights into the optimal designs of LFR power plants and addresses thermal, economic, and environmental considerations of utilizing molten salt with a large TES system as well as employing natural gas backup. The outcomes of the research address a wide audience including academics, operators, and policy makers. [ABSTRACT FROM AUTHOR]

Benefiting from its high thermal conductivity, simple structure, and light weight, the pulsating heat pipe (PHP) can meet the requirements for high efficiency, flexibility, and low cost in industrial heat transfer applications such as aerospace detector cooling and vehicle thermal management. Compared to a PHP working at room temperature, the mechanism of a PHP with hydrogen as the working fluid differs significantly due to the unique thermal properties of hydrogen. In this paper, a two-dimensional model of a hydrogen PHP with a filling ratio of 51% was established to study the flow characteristics and thermal performance. The volume of fluid (VOF) method was used to capture the phase distribution and interface dynamics, and the Lee model was employed to account for phase change. To validate the model, a comparison was conducted between the simulation results and experimental data obtained in our laboratory. The simulation results show that the pressure and temperature errors were within 25% and 5%, respectively. Throughout a pressure oscillation cycle, the occurrence of uniform flow velocity, acceleration, and flow reversal can be attributed to the changes in the vapor–liquid phase distribution resulting from the effect of condensation and evaporation. In addition, when the fluid velocity was greater than 0.6 m/s, dynamic contact angle hysteresis was observed in the condenser. The results contribute to a deeper understanding of the flow and heat transfer mechanism of the hydrogen PHPs, which have not been yet achieved through visualization experiments. [ABSTRACT FROM AUTHOR]

The so-called internally channeled tube (ICT) is an innovative heat exchanger design proposed in our recent publications based on a channels-in-tube principle. A general, three-dimensional numerical model was suggested to describe fluid dynamics and heat transfer in the ICT. This model has already been validated for turbulent flow. The current paper presents an experimental investigation of the ICT and the model validation under laminar flow conditions. The experimental set-up and measurement procedure are given in detail and the maldistribution issue is addressed. The deviation between simulated and measured values is below 11% for the pressure drop and below 8% for the wall and bulk temperatures. Furthermore, the ICT performance was evaluated using performance evaluation criterion (PEC) including both heat transfer rate and pressure drop. Enhanced heat transfer in the ICT surpasses the associated pressure drop increase, yielding a PEC greater than one. [ABSTRACT FROM AUTHOR]

Steady flow of incompressible Maxwell–Sutterby fluid at stretching sheet is discussed in the presence of stagnation point region. The magnetic Reynolds number is considered very high and induced magnetic and electric fields are applied to the fluid flow. Temperature-dependent properties with radiation influence are considered in this analysis. The heat source or sink and melting impact are also debated in this analysis. A differential model of mathematics is developed by employing a governing constitutive equation. The differential equations' model is condensed and becomes ordinary differential equations by implementing the appropriate transformations. Furthermore, these equations are elucidated by the numerical scheme. The physical influence of physical parameters is exhibited in the graphs and tabular form. The escalating values of M cause a shear thinning attitude in the fluid; as a result, devaluation in the velocity is detected in the case of a / c = 0. 5 , while it depicted the counter behavior for a / c = 1. 5. The skin friction is heightened with improving values of Re because R e boosted which improved the viscosity of liquid as well as heightened the friction at sheet. The enhancing values of M p cause a decrement in skin friction. The melting parameter is enriched which reduces the viscosity of fluid due to temperature boosting as well as friction reduction. The diminution in skin friction is found for enhancing the values of β. [ABSTRACT FROM AUTHOR]

Next-generation sequencing (NGS) is emerging as a powerful tool for molecular diagnostics but remains limited by cumbersome and inefficient sample preparation. We present an innovative automated NGS library preparation system with a simplified mechanical design that exploits both macro- and microfluidic properties for optimizing heat transfer, reaction kinetics, mass transfer, fluid mechanics, adsorption–desorption rates, and molecular thermodynamics. Our approach introduces a unique two-cannula cylindrical capillary system connected to a programmable syringe pump and a Peltier heating element able to execute all steps with high efficiency. Automatic reagent movement, mixing, and magnetic bead-based washing with capillary-based thermal cycling (capillary-PCR) are completely integrated into a single platform. The manual 3-h library preparation process is reduced to less than 15 min of hands-on time via optimally pre-plated reagent plates, followed by less than 6 h of instrument run time during which no user interaction is required. We applied this method to two library preparation assays with different DNA fragmentation requirements (mechanical vs. enzymatic fragmentation), sufficiently limiting consumable use to one cartridge and one 384 well-plate per run. Our platform successfully prepared eight libraries in parallel, generating sequencing data for both human and Escherichia coli DNA libraries with negligible coverage bias compared to positive controls. All sequencing data from our libraries attained Phred (Q) scores > 30, mapping to reference genomes at 99% confidence. The method achieved final library concentrations and size distributions comparable with the conventional manual approach, demonstrating compatibility with downstream sequencing and subsequent data analysis. Our engineering design offers repeatability and consistency in the quality of sequence-able libraries, asserting the importance of mechanical design considerations that employ and optimize fundamental fluid mechanics and heat transfer properties. Furthermore in this work, we provide unique insights into the mechanisms of sample loss within NGS library preparation assays compared with automated adaptations and pinpoint areas in which the principles of thermodynamics, fluid mechanics, and heat transfer can improve future mechanical design iterations. [ABSTRACT FROM AUTHOR]

One of the major problems of using nanofluids in heat exchange applications is the forming and deposition of nanoparticles on the inner surface of the heat exchanger. In this paper, Water-Cmc fluid is used as a surfactant for nanoparticles to prevent deposition and congregation. The pressure drops and heat transfer in U-bend double pipe heat exchanger based on water-MgO-Cmc fluid, are examined. Nanoparticles of Magnesium Oxide (MgO) and Carboxymethyl Cellulose (Cmc) are used with pure water as a base fluid. The experimental rig and procedures are designed to facilitate various operational conditions such as flow rate, volume concentration of MgO particles and weight concentration of Cmc particles. Furthermore, convective heat transfer coefficient, heat exchanger effectiveness, pressure drop, friction factor, under different conditions, are measured. The results demonstrate convective heat transfer coefficient of U-bend double pipe heat exchangers is enhanced by 35% for 1 MgO vol.% and 0.2 Cmc wt.% compared to base fluid (Water-Cmc). It is concluded that pressure drops are directly proportion to the increase of MgO nanoparticles at same Cmc concentration by 23% at 0.2 wt.%. Whilst, friction factor of the system is inversely proportion to the increase of volumetric flow rate of water-MgO-Cmc fluid. An increase in MgO nanoparticle concentration increases the friction factor, hence maximum friction factor enhancement by 38% for MgO concentration of 1 vol.%. The effectiveness of heat exchanger is slightly increased by 8% with increase of MgO concentration and flow rate. Finally, thermo-physical characteristics of water-MgO-Cmc fluid at various temperatures, are measured [ABSTRACT FROM AUTHOR]

The study of microbial flow with nanofluids involves investigating the behavior and interactions of microorganisms in the presence of nanofluids. Nanofluids are colloidal suspensions containing nanoparticles dispersed in a base fluid, and they have unique properties that can significantly impact microbial flow dynamics. This research focuses on the simultaneous effects of melting heat, Joule heating, chemical reaction, and thermal radiation on an aligned magnetohydrodynamic Williamson nanofluid (WNF) with the Cattaneo–Christov heat flux model (CCHFM) comprising microorganisms near the leading edge having stagnation flow characteristics. A melting approach is employed to study the behavior of fluid flow and heat transfer in the presence of these combined phenomena. A mathematical model is developed based on the governing equations, including conservation equations for mass, momentum, energy, concentration and microbes. To analyze the system, a set of nonlinear partial differential equations is transformed into ordinary differential equations (ODEs) by using similarity measures. The solutions of these nonlinear ODEs are obtained via the RK-4th method in MATLAB, and the results are presented in graphs and tables. Boundary layer equations for microbe propagation, fluid temperature, nano-inclusion volume fraction, and fluid velocity are formulated and discussed for various influential parameters. A higher melting parameter M b results in thicker boundary layers for velocity and temperature profiles, accompanied by an increased concentration profile for α = π 4 . Notably, the trend is more pronounced in α = π 4 compared α = π 2 . The impact of Nb and Nt on the motile profile exhibits a positive influence, leading to an increased boundary layer thickness for the gyrotactic microorganisms. The numerical analysis in Table 1 reveals that the melting heat parameter has a more pronounced impact on the motile configuration, as evidenced by the respective rates of change (- 0.076783 , - 0.337954 , 0.597858 , 0.893040) for key physical quantities compared to other configurations. The convergence and validation of the numerical solutions ensure the accuracy and reliability of the findings, establishing a foundation for further research in this area. [ABSTRACT FROM AUTHOR]

Double-pipe helical heat exchangers (DPHHXs) are widely used for cooling and heating applications. In this study, a combination of two methods is used to enhance the performance of DPHHX. The thermal–hydraulic performance is investigated using a nanofluid of silicon dioxide and water (SiO2/water) as well as spring wire insert (SWI) experimentally and numerically. The numerical model is validated with the experimental results. The parameters such as Nusselt number, pressure drop, exergy efficiency, and thermal–hydraulic enhancement factor are investigated for Reynolds number range from 4500 to 7000. The results show the Nusselt number is enhanced with nanofluid employment and SWI. Nusselt number increases by 34% when 0.1% volume concentration of nanofluid is used and by 43.5% when spring wire is only used compared to base water. The configuration with a 0.3% volume concentration and SWI achieves the highest Nusselt number enhancement ratio, exhibiting a 174% increase compared to other configurations. In the same case, the pressure drop ratio reaches its peak at 157%. The exergy efficiency improves with an increase in nanoparticle volume concentration, with the 0.3% concentration with SWI showing the highest values, ranging from 54 to 65%. Among different concentrations, the SiO2/water nanofluid with a 0.2% volume concentration with SWI demonstrates the highest thermal–hydraulic enhancement factor, making it the optimal choice. The results prove that spring wire inert is more effective than nanofluid in the DPHHX. The contours, streamlines, and vectors of the temperature, velocity, and pressure distributions give more understanding for the heat transfer and fluid flow. [ABSTRACT FROM AUTHOR]

This investigation intends to analyze the influence of nanoparticles morphology on the magnetic flux dependent thermo-physical properties and magnetohydrodynamic free convection heat transfer performance of water-based magnesium ferrite ferrofluid under various volume fractions. The thermo-physical parameters of the ferrofluid suspended with cube shaped particles are examined at 25 °C using KD2 pro thermal analyzer, Ostwald viscometer and specific gravity bottle under magnetic flux. The free convection heat transfer is obtained using heat pipes assisted cubical enclosure. Without the influence of magnetic flux, the thermal conductivity of the ferrofluid was improved by a maximum of 12.75% at a volume fraction of 0.15%. At the same time, the maximum viscosity and density were raised by 32.92% and 6.11% at a volume fraction of 0.20% in comparison with water. Under the influence of 350 Gauss, thermal conductivity, and viscosity of ferrofluid enhanced by 21.81% and 37.41% while the density decreased by 4.91%. It was revealed that the addition of cube-shaped magnesium ferrite particles in ferrofluid improved the thermo-physical properties. The optimum concentration for maximum heat transfer is reduced to 0.025% with the use of cube shaped particles compared to other types of nanoparticles reported in previous studies. [ABSTRACT FROM AUTHOR]

The heat transfer enhancement and hydrodynamic characteristics of nanofluid use in a micro heat exchanger is investigated for cooling electronic components working in hot climatic conditions. The cooling fluid employed was water and TiO2 nanoparticles at mass concentrations of 1% and 5%, the Reynolds numbers ranged from 400 to 2000, and the inlet temperatures ranged between 35 °C and 65 °C. At a nanofluid inlet temperature of 55 °C and a nanoparticle concentration of 1%, the Nusselt number increased by 23% up to 54% as the Reynolds number varied between 400 and 2000. At a nanoparticle concentration of 5%, the percentages that correspondingly enhanced the Nusselt number were 32% and 63%. The temperature of the electronic heating component decreased by 4.6–5.2 °C when the nanofluid concentration was increased from 0 to 5% at a Reynolds number of 400 and a nanofluid inlet temperature of 35 °C. Small increments in the pressure drop of about 6% and 13% were observed at nanofluid concentrations of 1% and 5%, respectively. With nanoparticle concentrations of 1% and 5%, a Reynolds number of 2000, and a nanofluid inlet temperature of 35 °C, performance evaluation criterion (PEC) values of 1.36 and 1.45 were obtained. When the nanofluid inlet temperature increased to 65 °C, the PEC parameter decreased to 1.02–1.10 for both concentrations. [ABSTRACT FROM AUTHOR]

The Multiplexed Survey Telescope (MUST) project is led by Tsinghua University, which entrusted the European Industrial Engineering (EIE) GROUP with the design, manufacture, and assembly of the dome. Located on Saishiteng Mountain in Qinghai Province, MUST benefits from exceptional atmospheric seeing conditions etc. Local dome seeing may be comparable to atmospheric seeing and requires careful consideration. This research, based on numerical simulations, focuses on refining the dome structure and temperature regulation strategies to achieve optimal dome seeing. The existing simulations only consider nighttime dome seeing and overlook the impact of daytime dome heating on nighttime conditions. The Computational Fluid Dynamics (CFD) part mostly relies on a steady-state k − ε model, which cannot simulate transient processes or capture optical turbulence. In this study, a comprehensive multiphysics field coupling simulation was conducted, encompassing radiation heat transfer, fluid heat transfer, CFD, and ray tracing. Simulations include both daytime and nighttime scenarios, taking into account the daytime heating of the dome due to solar irradiation, as well as dome seeing under natural ventilation at night. The CFD utilizes the large eddy simulation model, enabling three-dimensional transient simulation and the simulation of optical turbulence. Ultimately, the broadening of the point spread function was statistically analysed after a certain integration time, facilitating a quantitative evaluation of dome seeing. This numerical simulation approach is closer to real world conditions, improving simulation accuracy and addressing the shortcomings of existing simulations. Some qualitative conclusions are consistent with practical engineering experience. In the end, the dome seeing was successfully regulated to 0.21 arcsec, meeting the observational requirements. [ABSTRACT FROM AUTHOR]

This study explores the flow of a non-Newtonian fluid between two rolls that are counter-rotating at the same speed and of equal size. The fluid's viscosity depends on temperature, and we investigate its theoretical impact on the thickness of the sheet and other engineering parameters relevant to the process. We derive non-dimensional mass and momentum balance equations using suitable transformation and the lubrication approximation theory. The expressions for velocity distribution, pressure gradient, flow rate, temperature profile, and pressure fields have been obtained by utilizing the perturbation method. After obtaining these expressions, we compute engineering quantities such as the roll separation force, streamline, Nusselt number, and the power input required to drive both cylinders based on the system's kinematical and geometrical parameters. We also obtain numerical solutions using the finite difference method and built-in (BVP method) in Maple. Further, we use response surface methodology and analysis of variance to determine what the mathematical models mean and whether they are good enough for sensitivity and optimization analysis of the heat transmission and roll separation force. Using statistical tools such as the R2, we determine that our Nusselt number and roll separation force provide the best solution for the considered model. Additionally, it has been observed that as the Weissenberg number increases, velocity tends to rise; conversely, velocity decreases with a higher velocity ratio. Also, the temperature profile is notably influenced by the Brickman number and increases with the increase in the Brickman number. It has also been noted that as the values of velocities ratio increase, the separation points shift toward the nip region, while concurrently, the coating thickness decreases. Furthermore, we also demonstrate that compression between analytical and numerical solutions for the considered problem of fluid flow, which suggests that the results presented here are reasonable. Finally, we compare our work with published studies to validate our findings. Hence, these factors help in an efficient fluid coating process and improve the substrate life. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate the heat transfer performance of three different mixtures of propylene glycol and De ionized water-based nanofluids in a mini hexagonal tube heat sink (MHTHS), as well as the influences of particle volume fraction and temperature on the thermo physical properties of nanofluids. The three different nanoparticles such as MgO, ZnO, and Al2O3 were dispersed in a mixture of Propylene Glycol (PG) and De ionized water (DIW) at four different volume fractions of 0.01, 0.02, 0.03, and 0.04 respectively. In colder regions, propylene Glycol was used as a better heat transfer fluid in miniature devices due to its anti-freezing properties. In this study, the experiment was conducted under two conditions First, the flow rate of DIW was maintained at 20L/h and the flow rate of three different nanofluids varied from 20 L/h to 50 L/h. Secondly, mixture proportions of 20%(PG)/80% (DIW) and 40% (PG)/60% (DIW) were taken as base fluids. The measurements of thermal conductivity and viscosity were also investigated. Experiments were performed to determine the heat transfer coefficient, Nusselt number, friction factor, and pressure drop of three different nanofluids flowing in an MHTHS were also investigated. Experimental results indicate that heat transfer coefficients and Nusselt number intensify with an increase in Volume fractions and Reynolds number. Consequently, friction factor and pressure drop were also investigated. The results revealed MgO-PG (20%)/DIW (80%) with 0.04VF results in a 36.6% enhancement in heat transfer rate compared to the base fluid. The Nusselt number for MgO-PG (20%)/DIW (80%) at 0.04VF showed an enhancement of 25.6% compared to the base fluid. ZnO-PG (40%)/DIW (60%) had a higher friction factor and pressure drop than the base fluid. Finally, the Reynolds number of nanofluids for selected velocity and contour escalated with increasing temperature and decreased with higher volume fraction. By optimizing the volume fraction of MgO-PG (20%)/DIW (80%) based nanofluids, the performance and longevity of miniature devices in colder regions can be effectively enhanced by providing an efficient cooling solution. [ABSTRACT FROM AUTHOR]

The current article deals with a novel idea of a suspension of spherical silver Ag , cylindrical aluminium oxide Al 2 O 3 and platelet aluminium Al nanoparticles in water–ethylene glycol as a conducting fluid through a convective stretching surface. The effects of induced magnetic field, heat sink or source, thermal radiation and slip condition aspect are also incorporated during ternary hybrid nanofluid flow. The significance of the current investigation lies in enhancing heat transfer efficiencies, high-temperature processes, electronic devices where heat is generated or cooling systems and metal casting. The numerical solutions of nonlinear ordinary differential are obtained by employing a finite difference approach via the bvp4c solver (MATLAB package). The obtained results pointed out that the spherical silver nanoparticles provide a higher rate of heat transfer followed by cylindrical alumina nanoparticles and platelet aluminium nanoparticles, respectively. Moreover, the velocity profile and induced magnetic profile decrease with increasing volume fraction of spherical Ag nanoparticles, cylindrical Al 2 O 3 alumina nanoparticles, platelet Al nanoparticles and induced magnetic parameter. The ternary hybrid nanofluid's heat transfer rate is greatly increased by larger values of the radiative parameter, Biot number and slip parameter. Additionally, the temperature profile is improved when the heat source parameter grows while the heat sink parameter decreases. [ABSTRACT FROM AUTHOR]

This work proposes a combined strategy of simultaneously optimizing both the channel side and the fluid side for enhanced thermic behavior management of normal channel facile heat sinks. Primarily, a new header of normal channel facile heat sink is suggested. Later, a numerical exploration is executed to observe the best thermal performance case of hybrid nanofluids (CuO, Al2O3 and TiO2/H2O) at varying combination ratios and volumetric concentrations. Trapezoidal header design is recommended based on the outcome of the numerical study when compared with isosceles triangular header. Further, to access heat removal capability of hybrid nanofluids, three different combinations as CuO + Al2O3, TiO2 + CuO, and Al2O3 + TiO2 have been considered numerically. Three volumetric ratios of each combination of the hybrid nanofluids are tested, i.e., 75:25, 50:50, and 25:75. Experiments are performed using outcomes from numerical investigations. Compared to water, using Al2O3–TiO2/H2O hybrid nanofluid in trapezoidal header normal channel facile heat sink, highest drop observed in base temperature and thermal resistance is up to 14.27% and 23.44%, respectively, while the maximum increase in heat transfer, convective heat transfer coefficient, Nusselt number, and change in pressure is 3.98%, 29.49%, 27.77, and 13.21%, respectively. [ABSTRACT FROM AUTHOR]

The present study's goal was to investigate the efficiency of applying carbon/water Nanofluid and triangular baffles in the double-tube heat exchangers. The Reynolds number was in the range of 4000 to 14,000, and the carbon/water Nanofluid, which was with various volume fractions ranged between 0.1 and 0.3 volume percentages, was applied. Moreover, triangular baffles were implemented as turbulators with the numbers of 4, 8, and 12, as well as angles of 70 ∘ and 40 ∘ . Using the response surface method, the experiments design was carried out. The prediction process was eventually conducted using Perceptron artificial neural network that included the input data of Reynolds number, Nanofluids volume fraction, baffles number and angle, as well as Nusselt number target. Results showed that the simultaneous use of 12 triangular baffles at the 40 ∘ angle and a Nanofluid with a 0.3 volume fraction led to the 35% increase in Nusselt number compared to applying smooth tubes and water-based fluid. The coefficient of friction with a 0.3% volume fraction of Nanofluid associated with 12 triangular baffles at a 40 ∘ angle was, respectively, 5–10% and 1.5 times higher than that of the water flow within a smooth tube without the presence of baffles and Nanofluids. Moreover, results of Perceptron artificial neural network showed that applying a 1-32-4 topology and Levenberg–Marquardt algorithm would derive 0.98828 and 3.6275 values for the mean squared error (MSE) and coefficient of correlation, respectively. [ABSTRACT FROM AUTHOR]

The aim of this experimental and modeling work is to compare the thermal efficiency of two identical parabolic trough solar collector systems under weather conditions in Amman, Jordan, using a hybrid nanofluid of MWCNTs and Y2O3 with gum Arabic surfactant, and distilled water as the heat transfer fluid (HTF). One parabolic trough collector (PTC) uses a hybrid nanofluid at four different volumetric concentrations (0.01, 0.025, 0.05, and 0.1%), while the other uses water as a HTF. To prepare the nanofluids and check their stability, the thermal efficiency of the PTC was examined for different hybrid nanofluid concentrations compared to distilled water. The results showed that the 0.1% MWCNTs and Y2O3 hybrid nanofluid had the highest thermal efficiency of 44.24%, while water had a thermal efficiency of 19.32%. In addition, increasing the concentrations resulted in an improvement in the maximum optical efficiency. The maximum efficiency of 45% was obtained using 0.1% Vol. The Solidworks model was created according to experimental setup parameters and dimensions. The simulation was conducted under steady-state operating conditions, incorporating dimensional governing equations (continuity, momentum, and energy). A uniform heat flux was applied with two primary boundary conditions: the first one was at the receiver inlet where the fluid inlet temperature and mass flow rate were specified, whereas the second one was at the receiver outlet, where the outlet pressure was equivalent to the atmospheric pressure. The obtained experimental results have been compared using the Solidwork simulation model, which was created to determine the PTC's outlet temperature and thermal efficiency. The comparative results demonstrated remarkable precision with an average outlet temperature of 0.03% and thermal efficiency of 0.9%. [ABSTRACT FROM AUTHOR]

In recent scenario world is facing the problem of energy consumption. Researchers are keen on developing less energy consuming devices; in this regard, heat transfer using nanofluid has got the attention of current researchers for application in heat exchangers. In present study, an experiment was performed on double pipe heat exchanger using CuO-water nanofluids and sodium lauryl sulphate as the surfactant to examine the thermal performance factor (TPF) and pressure drop. The studies were conducted for a single phase fully developed flow with volume fractions of 0.005%, 0.02%, 0.04%, and 0.07% in the turbulent range between Reynolds numbers 5500 and 15,000. Along with thermal conductivity, Brownian motion and thickness of interfacial layer are also responsible for heat transfer enhancement in heat exchangers. For a volume fraction of 0.07% at Reynolds number 5500, the maximum enhancement in Nusselt number was observed 67.9% with the penalty of 189.47% increase in friction factor. The highest TPF recorded during the experiment is 1.18 for a volume fraction of 0.07% at 5500 Reynolds number. In present study a novel correlation was also developed for Nusselt number and friction factor. For better understanding the characterization of CuO nanoparticle, XRD, FeSEM, and EDS testing were conducted in the laboratory. [ABSTRACT FROM AUTHOR]

In the selection and design of ionic liquids (ILs) for various applications, including heat transfer fluids, thermal energy storage materials, fuel cells, and solvents for chemical processes, heat capacity is a key thermodynamic property. While several attempts have been made to develop predictive models for the estimation of the heat capacity of ILs in their liquid phase, none so far have been reported for the ILs' solid crystal phase. This is particularly important for applications where ILs will be used for thermal energy storage in the solid phase. For the first time, a model has been developed and used for the prediction of crystal phase heat capacity based on extending and modifying a previously developed hybrid group contribution model (GCM) for liquid phase heat capacity. A comprehensive database of over 5000 data points with 71 unique crystal phase ILs, comprising 42 different cations and 23 different anions, was used for parameterization and testing. This hybrid model takes into account the effect of the anion core, cation core, and subgroups within cations and anions, in addition to the derived indirect parameters that reflect the effects of branching and distribution around the core of the IL. According to the results, the developed GCM can reliably predict the crystal phase heat capacity with a mean absolute percentage error of 6.78%. This study aims to fill this current gap in the literature and to enable the design of ILs for thermal energy storage and other solid phase applications. [ABSTRACT FROM AUTHOR]

A numerical investigation was carried out in ANSYS Fluent® on a photovoltaic/thermal (PV/T) system with MXene/water nanofluid as heat transfer fluid (HTF). The interaction of different operating parameters (nanofluid mass fraction, mass flow rate, inlet temperature and incident radiation) on the output response of the system (thermal efficiency, electrical efficiency, thermal exergy efficiency, and electrical exergy efficiency) was studied using a predictive model generated using response surface methodology (RSM). The analysis of variance (ANOVA) method was used to evaluate the significance of input parameters affecting the energy and exergy efficiencies of the nanofluid-based PV/T system. The nanofluid mass flow rate was discovered to be having an impact on the thermal efficiency of the system. Electrical efficiency, thermal exergy efficiency, and electrical exergy efficiency were found to be greatly influenced by incident solar radiation. The percentage contribution of each factor on the output response was calculated. Input variables were optimized using the desirability function to maximize energy and exergy efficiency. The developed statistical model generated an optimum value for the mass flow rate (71.84 kgh−1), the mass fraction (0.2 wt%), incident radiation (581 Wm−2), and inlet temperature (20 °C). The highest overall energy and exergy efficiency predicted by the model were 81.67% and 18.6%, respectively. [ABSTRACT FROM AUTHOR]

The use of nanofluids for convectional heat transfer has become a spry area of research in recent years with the aim of improving heat transfer efficiency. Hybrid nanofluids have attracted significant attention and are advancing research and industrial applications since they involve employing more than one type of nanoparticle(s) in a base fluid. They enhance heat transfer by combining the chemical and physical properties of several nanoparticles concurrently and providing the properties in a homogeneous state. However, few experimental studies have focused on natural convective heat transfer using hybrid nanofluids. In this study, the natural convection of alumina – multiwalled carbon nanotube/water hybrid nanofluids formulated using a two-step method at a percentage weight ratio of 10:90 Al2O3: MWCNT at various nanoparticles volume concentrations of 0.00, 0.05, 0.10, 0.15, and 0.20 vol% was studied inside a square cavity (AR = 1) with two vertical walls which are isothermal, aimed at the Rayleigh number (Ra) range of 2.81 × 108 to 8.58 × 108. The average Nusselt number (Nuav), heat transfer coefficient (hav), heat transfer (Qav), and Rayleigh number (Ra) were considered at varying temperature gradients of 20°C – 50°C. Al2O3-MWCNT/water hybrid nanofluid with 0.10 vol% volume concentration was discovered to have the maximum value for hav,Qav, and Nuav. However, it was also observed that a further increase in the hybrid nanoparticles' volume concentration led to their deterioration at various temperature gradients. The maximum enhancements of 44%, 49%, and 42% were noted for hav,Qav, and Nuav, respectively, at ∆T = 50 °C, in comparison with the base fluid. Al2O3-MWCNT/water hybrid nanofluids application in a square cavity demonstrated enhanced natural convection. This present study concluded that hybrid nanofluids as heat transfer fluid significantly improved heat transfer performance compared to the base fluid. [ABSTRACT FROM AUTHOR]