Copper Nanofluid Research Articles

Enhanced heat transfer performance in a parabolic trough solar collector: A CFD investigation of silver and copper nanofluids utilizing porous medium

A recent study was being conducted to offer a three-dimensional numerical inspection of the water–Ag/Cu nanofluids’ hydrothermal profitability within a parabolic-trough solar collector incorporating a porous medium. This study aims to improve the thermal efficiency of parabolic-trough solar collectors by integrating nanofluids and porous media into the receiver tube. The focus is on enhancing heat transfer to the working fluid for better performance. In our numerical simulation, the working fluid of water (or nanofluid) at 5 different mass flow rates of 20, 40, 60, 80, and 100 L/h and with a temperature of 20°C enters the receiving pipe of a parabolic-trough solar collector while the non-constant heat flux is set on it. Copper and silver nanoparticles in volume fractions of (0.1 to 0.5%) and Darcy numbers of 0.1, 0.01, and 0.001 are simulated in applied porous media. The results of the simulations revealed that the use of a porous medium with (rp = 1 and Da = 0.1) and also in mass flow rate of 20 L/h, our receiver pipe saw a 2204.8% increase in the Nusselt number and 687.8% pressure drop, and the PEC was equal to the number 11.3. In the following, we examined copper and silver nanoparticles in two cases of applying porosity and without applying porosity in the receiving tube in volume fractions of 0.1 to 0.5%. Due to the creation of a high-pressure drop by the porous medium, nanofluids showed higher numbers for the performance evaluation criterion than unity for the non-porous state. Silver nanoparticles in volume fraction of 0.5% (at rp = 1 and Da = 0.1) showed an increase of 71.3% and 197.8%, respectively, for the Nusselt number and pressure drop. In the case of non-porous copper nanoparticles with a volume fraction of 0.5%, they showcased an uptick in 217.6% and 3.8% respectively for the Nusselt number and pressure drop.

Experimental Investigation of Heat Transfer Characteristics of Copper Nanofluid Under Subcooled Flow Boiling Conditions

Experimental Investigation of Heat Transfer Characteristics of Copper Nanofluid Under Subcooled Flow Boiling Conditions

Fructose-mediated single-step synthesis of copper nanofluids with enhanced stability and thermal conductivity for advanced heat transfer applications

A precisely controlled solution-phase approach was employed to synthesize copper nanofluid through the reduction of copper sulfate by fructose in the presence of cetyltrimethylammonium bromide, utilizing a mixture of water and ethylene glycol in 1:1 ratio as the base fluid. We delved into the nanofluid’s thermal conductivity and rheological properties, with a keen interest on particle size and reaction rates that exhibited significant sensitivity to variations in reaction parameters. The homogeneous dispersion of nanoparticles in the base fluid resulted in an augmentation of thermal conductivity to 2.31 Wm−1K−1 for particle loading fraction of 0.19%, with a never before achieved stability of 9 months. This method has proven to be not only straightforward and dependable but also efficient for the rapid synthesis of highly stable Newtonian nanofluids, underscoring the nanofluid’s potential for highly powerful cooling applications.

Numerical examination of expanding the effectiveness of thermal photovoltaic framework by changing the level of heat transfer conveyance

In photovoltaic systems, only a tiny portion of solar radiation reaches the module's surface and is converted to electrical energy. The remaining solar radiation is wasted, which raises cell temperature and reduces electrical efficiency. This research focused on examining the effects of different factors on nanofluids. In the simulations performed in this thesis, the inlet temperature of the water fluid changes from 5°C to 30°C. The radiation intensity equals 600W per square meter, and the input speed is 0.07452m per second. The innovation of this article is the use of two nanofluids of aluminum oxide and copper together with a mixture of water to investigate the effect of effective parameters on the electrical, thermal, and overall efficiency of photovoltaic systems, such as the amount of incoming radiation to the surface of the panel, the temperature of the fluid inlet in mountainous areas, the temperature of the absorber. , so that the thermal efficiency of copper and aluminum oxide is investigated and compared. As a result, copper nanofluid can increase the ratio more than aluminum oxide and pure water. There is a direct relationship between the output fluid temperature and the input temperature. With an increase in the input fluid temperature, the output temperature also increases proportionally. Increasing the inlet temperature affects the temperature of the absorber surface, which, in turn, reduces the electrical efficiency of the photovoltaic system. These changes are reduced by adding nanofluids to the photovoltaic system.Although the increase of nanoparticles causes a decrease in the temperature of the absorber plate, and this temperature decrease for copper nanofluid is 10% higher than that of aluminum oxide and pure water until the volume fraction is reached.

Design, synthesis, and characterization of stable copper nanofluid with enhanced thermal conductivity

Nanofluids, which are liquids that contain small particles with dimensions in the nanometer range, have gained significant attention in recent years due to their enhanced thermal properties in various applications such as thermal management and energy conversion. This article aims to provide insights into the design and optimization of copper nanofluid synthesis and it investigates the thermal and rheological properties at varying concentrations of nanoparticles and temperature. The method involves simultaneous use of fructose as reducing agent and polyvinyl pyrrolidone as stabilizing agent to enable synthesis of copper nanofluid from copper sulphate. The resulting Newtonian nanofluid had a stability of 3 months with enhanced thermal conductivity of up to ∼500 % compared to 1:1 mixture of water and ethylene glycol which served as the base fluid. The approach is suitable for producing large volume of nanofluid using cost effective materials.

Numerical and statistical analyses of three-dimensional non-axisymmetric Homann's stagnation-point flow of nanofluids over a shrinking surface

Nanofluids, which are known for their superior heat transfer properties, have become indispensable in real-world applications. This underscores the critical importance of comprehensive understanding, which forms the core of this study. The goal of this study is to scrutinize Homann's non-axisymmetric stagnation-point flow over a shrinking surface of various single-phase water-based nanofluids (water-copper, water-alumina, and water-titanium dioxide) in a three-dimensional (3D) system. The model formulations are derived into ordinary differential equations via sophisticated similarity variables that satisfy the continuity equation. A boundary value problem solver (bvp4c) with a finite difference method in MATLAB is adapted to carry out numerical calculations while the response surface methodology (RSM) in MINITAB is used to statistically analyze the solution. The opposing flow created by the shrinking surface within a certain degree of shrinkage leads to the formation of two distinct alternative solutions. The current study offers two alternative solutions for boundary layer flow control modeling. However, only the first solution is tested to be stable. The critical point for boundary layer bifurcation is identified, to efficiently manage the flow. Water-copper nanofluid has been proven to perform better in heat transfer than water-alumina and water-titanium dioxide nanofluids. The 2 % volume fraction of copper provides better heat transfer compared to 1 % volume fraction in the present configuration of the flow system. The response optimizer via RSM also validates that the heat transfer performance of copper nanofluid is maximized when the volume fraction of copper is set at a high level with a low shear-to-strain rate.

Unsteady magnetohydrodynamic free convection and heat transfer flow of Al2O3‒Cu/water nanofluid over a non-linear stretching sheet in a porous medium

This article investigates the impact of time-dependent magnetohydrodynamics free convection flow of a nanofluid over a non-linear stretching sheet immersed in a porous medium. The combination of water as a base fluid and two different types of nanoparticles, namely aluminum oxide (Al2O3) and copper (Cu) is taken into account. The impacts of thermal radiation, viscous dissipation and heat source/sink are examined. The governing coupled non-linear partial differential equations are reduced to ordinary differential equations using suitable similarity transformations. The solutions of the prin-cipal equations are computed in closed form by applying the MATLAB bvp4c method. The velocity and temperature pro-files, as well as the skin friction coefficient and Nusselt number, are discussed through graphs and tables for various flow parameters. The current simulations are suitable for the thermal flow processing of magnetic nanomaterials in the chemical engineering and metallurgy industries. From the results, it is noticed that the results of copper nanofluid have a better impact than those of aluminium nanofluid.

A direct approach towards synthesis of copper nanofluid by one step solution phase method

We adopted a simple one step approach to synthesize copper nanofluids by reduction of copper sulphate with fructose. The solution phase synthetic technique led to the formation of copper particles whose size was restricted to the nanodimensions by use of sodium lauryl sulphate. We studied the effect of various parameters on the formation and dispersion of the copper nanoparticles in the base fluid containing a 1:1 mixture of water and ethylene glycol. The resulting Newtonian nanofluid was found to be highly stable with increased thermal conductivity. Thus, the applied technique is found to be simple, economic, and extendable to other class of materials to obtain stable dispersions of nanofluids for heat transfer applications.

Numerical investigation of increasing the efficiency of thermal photovoltaic system by changing the level of heat transfer distribution

In photovoltaic systems, only a small fraction of solar radiation effectively reaches the module's surface and is converted into electrical energy. The unused solar radiation results in elevated cell temperature and reduced electrical efficiency. In the photovoltaic-thermal system, the circulation of fluids such as water or air around the panels allows for the utilization of otherwise wasted thermal energy, leading to increased electrical efficiency and overall system efficiency. The objective of this article is to examine the thermal efficiency of copper and aluminum oxides in photovoltaic systems when combined with nanofluid. The aim is to identify any changes in efficiency that may arise from this combination. This article presents a novel approach by employing a combination of aluminum oxide and copper nanofluids, along with a water mixture, to investigate the influence of key factors on the electrical, thermal, and overall efficiency of photovoltaic systems. These factors encompass incoming radiation levels on the panel surface, fluid inlet temperature in mountainous regions, and absorber temperature. The study aims to analyze and compare the thermal efficiency of copper and aluminum oxide in this particular context. In the present study, the finite volume method is used to solve the equations. According to the research findings, raising the initial temperature of the incoming fluid results in a proportional increase in the outlet temperature. However, it is important to note that the thermal efficiency remains constant regardless of changes in the initial fluid temperature. Furthermore, copper oxide exhibits superior thermal efficiency compared to aluminum oxide, and the use of nanofluids enhances the thermal efficiency of photovoltaic systems.

A NOVEL MACHINE LEARNING STUDY: MAXIMIZING THE EFFICIENCY OF PARABOLIC TROUGH SOLAR COLLECTORS WITH ENGINE OIL-BASED COPPER AND SILVER NANOFLUIDS

Estimating the heat transfer parameters of parabolic trough solar collectors with machine learning is crucial for improving the efficiency and performance of these renewable energy systems, optimizing their design and operation, and reducing costs while increasing the use of solar energy as a sustainable power source. In this study, the heat transfer characteristics of two different nanofluids flowing through the porous media in a straight plane underneath thermal jump conditions were investigated by machine learning methods. For the flow in the parabolic trough solar collector, two different nanofluids obtained from silver- and copper-based motor oil are considered. Flow characteristics were obtained by nonlinear surface tension, thermal radiation, and Cattaneo–Christov heat flow, which was used to calculate the heat flow in the thermal boundary layer. A neural network structure was established to estimate the skin friction and Nusselt number determined for the analysis of the flow characteristic. The data used in the multilayer neural network, which was developed using a total of 30 data sets, were divided into three groups as training, validation, and testing. In the input layer of the network model with 15 neurons in the hidden layer, 10 parameters were defined and four different results were obtained for two different nanofluids in the output layer. The prediction performance of the established neural network model has been comprehensively studied by means of several performance parameters. The study findings presented that the established artificial neural network can predict the heat transfer characteristics of two different nanofluids obtained from silver- and copper-based motor oil with deviation rates less than 0.06%.

Performance of copper nanofluid on changing width of stretching sheet using thermal radiation and heat flux

The phenomenon of nanomaterial carrying fluid flow over a non-linear elongated sheet with changing thickness is investigated in this study. The present research focuses at the flow of magnetic nanofluid over non-linear elongated sheets of different thicknesses, with an emphasis on copper nanoparticles distributed in water. The phenomena, which is significant in many industrial applications including paper manufacturing and atomic reactors, is analysed using Prandtl boundary layer theory and Navier-Stoke's equation. The study covers a wide range of physical features. There have been fewer works on the mathematical modelling of stretching sheets with varying widths. The main aim of investigation is to analyse the effect of EMHD, as well as other characteristics like Eckert number, Boit number, radiation effect and absorption factor. Paper manufacturing, dye and filament extrusion, atomic reactors, and metallurgical processes all rely heavily on these sheets of varied widths. The problem employs Navier-Stokes' equation and Prandtl boundary layer theory. The similarity transformation converts partial differential equations into ordinary differential equations. MATLbvp4c programme is used to obtain numerical solutions. The present study helps to achieve desired quality of stretching sheet.

Cooling Performance of Turning M2 steel by using copper nanofluids

Cooling Performance of Turning M2 steel by using copper nanofluids

Implicit Finite Difference Simulation of Hybrid Nanofluid along a Vertical Thin Cylinder with Sinusoidal Wall Heat Flux under the Effects of Magnetic Field

A numerical analysis of magnetohydrodynamic natural convection along a thin vertical cylinder with a sinusoidal heat flux at the wall immersed in copper (Cu) and aluminum-oxide (Al2O3) hybrid nanofluids has been studied. A 2D vertical thin cylinder shape geometry has been considered with a radius of R. The fluid flow is considered laminar and incompressible with the Prandtl number of Pr = 6.2 and 10% concentration of hybrid nanoparticles. The nondimensional governing equations have been solved numerically by using the implicit finite difference method. An in-house FORTRAN 90 code is used for solving this problem and the code is validated with the available benchmark results. Numerical simulations have been performed for a wide range of governing parameters, Hartmann number from Ha = 0 to Ha = 4, nanoparticles volume fractions ϕ = 0.0 to ϕ = 0.1, and the amplitude of the wall heat flux ε = 0.0–0.3. The findings have been illustrated in terms of streamlines, isotherms, local skin friction coefficients, local Nusselt numbers, velocity, and temperature distributions. The flow field and temperature distribution within the boundary layer are deceased by the effects of the wall heat flux amplitudes. It is also noted that the rate of heat transfer increases with particle volume fraction and the amplitude of the wall heat flux. According to the findings, Nu increases by 24.72% as ϕ increases from 0 to 0.1 while ε = 0.3, and 27.66% while ε increases from 0.0 to 0.3 at 5% hybrid nanoparticles. The local skin frictions and Nusselt number diminish with the increment of the Hartman number due to the effects of the Lorenz force. The findings of this study can lead to a better understanding of the fundamental principles regarding the behavior of hybrid nanofluids under complex conditions, such as a vertical thin cylinder with a sinusoidal wall heat flux. Understanding the behavior of hybrid nanofluids in the presence of a magnetic field and a nonuniform wall heat flow can also lead to the development of innovative heat transfer enhancement strategies.

Acoustothermal dynamic characteristics of water-based copper nanofluids on a vibrating nanosurface

The high-frequency vibration is a potential method to induce evaporation and boiling of nanofilm by acoustothermal effect. Here, we investigate the acoustothermal dynamic characteristics of water-based copper nanofluids on a vibrating nanosurface using molecular dynamics simulation. Regimes of the evaporation, nucleate boiling and film boiling can be classified at different amplitudes (A) and frequencies (f). Under the same vibration condition, the introduction of the nanoparticle is conducive to the evaporation and boiling outcome, which becomes superior with the increase of the nanoparticle diameter. Change rules of acoustothermal atomization modes depend on A and f, which are similar for basefluid and nanofluids. There is a negative linear relationship between the nonevaporating layer height and Af3/2 when Af3/2 is smaller than the turning point. Underlying reasons for the enhancement of the evaporation and boiling by adding the nanoparticle rest with the irregular Brownian motion and spinning motion of the nanoparticle, which intensifies disturbance in the water nanofilm. Moreover, a layer of water molecules is absorbed around the nanoparticle to ameliorate heat transfer and thus facilitates the evaporation and boiling of the water nanofilm on a vibrating nanosurface.

The feasibility of using magnetic refrigeration cycles in the thermal management of rechargeable batteries in electric cars

This is the first study that intends to check the feasibility of using a magnetic refrigerator (MR) in the thermal management of rechargeable batteries instead of other conventional passive/active cooling techniques. A mathematical model has been generated to study the cooling performance of the proposed system at different conditions, including synchronized and asynchronized cooling at different discharge rates and ambient temperatures, in addition to exploring the effect of using water-based copper (Cu) nanofluid as a heat transfer fluid in a spherical packed bed active magnetic regenerator on the cooling performance. The proposed system can maintain the maximum temperature of the battery pack to less than 35 °C with high coefficients of performance (COPs) [between 4.8 and 9.7] during synchronized and asynchronized cooling at an ambient temperature of 25 °C and different discharge rates. The system can operate with COP higher than 1 at an ambient temperature up to 40 °C during 0.5 discharge rate, and up to 38 °C ambient temperature during 1 discharge rate. The MR can work with COP of 5.3 compared to 3.82 for vapor compression refrigeration system (VCRS) if the two systems meet a 3-kW cooling load. The study reveals that MR outperforms many active cooling techniques especially when appropriately integrated with the thermal management of the vehicle cabin.

Semi-analytical solution of nanofluid flow with convective and radiative heat transfer

The application of nanofluids has exploded in recent decades to improve the local number, mean Nusselt number, and rate of heat transfer. However, boundary layer equations of nanofluid across a flat plate with radiation have not been studied, and therefore this paper studies them mathematically for the first time. For water-based copper and aluminum oxide nanofluids, a similarity solution is presented in this study, and the subsequent system of the ordinary differential equation (ODE) is numerically solved by the Runge–Kutta method in MATLAB. Two different hydraulic boundary conditions are used in the simulations. In the first, the flow across a moving plate and the direction of the flow are analyzed, while in the second, the flow over a nonlinearly moving plate in a still fluid is investigated. The nanoparticle’s boundary layer thickness is found less than the thermal and hydraulics boundary layers. The local Nusselt number and friction factor of both the nanofluids are calculated and compared with the base fluid. The results demonstrate that the friction coefficient is high and the Nusselt number is low for nanoparticles with a high volume fraction. It also revealed that the friction factor for water–aluminum oxide is 16% greater than that for the water–CuO whereas the local Nusselt number for water–aluminum oxide is only 5% more than that for the water–CuO.

Thermal performance of copper-distilled water nanofluid in a wavy channel

This paper carried out an experimental study to synthesize and characterize copper water based nanofluid. To do so nanoparticles were fabricated by using one-step pulsed Nd: YAG laser ablation method under ambient conditions. Copper substrate was ablated for the duration of 25 min to ensure enough volume fraction of nanoparticles inside the host fluid. Energy dispersive spectroscopy (EDS) and scanning electron microscopy were done. The morphology of the nanoparticles seems to be homogeneous. The size distribution analysis resulted in the average size of 100 nm. Also, UV–Vis spectroscopy analysis was done for four months to investigate the stability of the synthesized nanofluid. It is observed that the nanofluid is not enough stable for more than one month. On the other hand, numerical simulations were done employing Ansys Fluent software to study thermal behavior of copper nanofluid in a corrugated channel. It is observed that higher volume fraction of nanoparticles leads to the higher heat transfer rate. Also, in this study, hydrophobic wavy wall with a constant temperature was considered as a hydrodynamical approach to enhance the heat transfer rate. It is concluded that hydrophobicity contributes to the increment of Nusselt number up to 45 percent in laminar flow. Meanwhile, Discrete phase method, which attribute to the Eulerian Lagrangian approach, was simulated. Outcomes indicated that DPM method can be trusted by less than 2% error in laminar flow.

Enhanced heat transfer of laser-fabricated copper nanofluid at ultra-low concentration driven by the nanoparticle surface area

As solar thermal energy systems are an important pillow toward green energy production, the enhancement of their thermophysical properties using nanofluids is a highly relevant topic. However, when nanofluids are designed by the addition of nanoparticles (NPs), their colloidal stability is frequently impaired during high-temperature processing, a phenomenon related to particle size, morphology, and concentration. In this work, we synthesized nanofluids composed of ligand-free colloidal CuNPs dispersed in ethylene glycol by continuous-flow, picosecond-pulsed laser ablation in liquids synthesis, yielding monomodal-CuNPs with mean diameters of 2.5 and 4.8 nm. The nanofluids’ thermal conductivity (knf) was measured using a guarded-hot-plate method in the temperature range from 298 to 318 K. We observed a nanoparticle surface area-dependent enhancement of the knf up to 30 % at ultra-low volume concentration of 20 ppm. This corresponds to 30 times higher concentration-normalized knf in comparison to the state-of-the-art, while the resulting nanofluids retain their rheological properties. The findings are matched with Yu–Choi’s theoretical model calculations, indicating that heat transfer at the nanoparticle-solvent interface is driven by an interfacial layer of solvent molecules. These findings highlight the suitability of laser-fabricated ligand-free CuNPs as additives for heat transfer fluids, maximizing performance in mid-temperature heat transfer applications like solar thermal collectors.

Computational Analysis of Soret and Dufour Effects on Nanofluid Flow Through a Stenosed Artery in the Presence of Temperature-Dependent Viscosity

Abstract In this study, the Soret and Dufour effects in a composite stenosed artery were combined with an analysis of the effect of varying viscosity on copper nanofluids in a porous medium. Blood viscosity, which changes with temperature, is taken into account using the Reynolds viscosity model. The finite difference approach is used to quantitatively solve the governing equations. For use in medical applications, the effects of the physical parameters on velocity, temperature and concentration along the radial axis have been investigated and physically interpreted. The results are graphically displayed and physically defined in order to facilitate comprehension of the various phenomena that occur in the artery when nanofluid is present. It is observed that the Soret effect increases the rate of heat transfer but decreases the rate of mass transfer. The new study enhances knowledge of non-surgical treatment options for stenosis and other abnormalities, hence reducing post-operative complications. Additionally, current research may have biomedical applications such as magnetic resonance angiography (MRA), which provide a picture of an artery and enable identification of any anomalies, and thus may be useful

An Analysis of Buoyancy-Driven Heat Behaviour and Flow Pattern of a Water-Copper Nanofluid in a Cylindrical Conduit

The flow of fluids and heat characteristics through free convection within an enclosed space has gained substantial study due to the various applications in manufacturing industries. This work examined the influence of buoyancy factors on normal convection in a heated tube filled with Copper (Cu) nanofluid. The method of finite difference was employed to characterize the regulating fluid formulae, and C++ programming language was employed to evaluate the Navier Stoke and continuity fields. This study examined Cu nanoparticles with particle sizes ranging from 1% to 10% and buoyancy values between 2.6 x 103 and 2.8 x 103 N. Cu nanofluid was used as the working fluid and the findings are presented as temperature gradient, Nusselt number, stream function, and vorticity curves. The findings revealed that an increase in the weight proportions of nanoparticles to 0.04 amplifies the buoyancy parameters to the highest value of 2.75 x 103 N; it yields a substantial enhancement in the heat transport rate by convection. Also, as the buoyancy factor increases, the temperature gradient, vorticity, and stream function of the nanofluid improve, while the local drag coefficient decreases. This study advances the understanding of buoyancy-driven convective flow and heat behavior in the technical design of floating vessels for safety and effectiveness.