Pure Nanofluid Research Articles

A thermal energy analysis of binary (Go-Co/H2O) and ternary (Go-Co-Zro2/H2O) nanofluids based on characterization and thermal performance

Hybrid or binary nanofluids have superior mechanical and thermal characteristics but the tri-hybrid nanofluids comprise of more embellished thermal properties, better physical strength, and enhanced stability. The present work characterizes the thermal and physical aspects of the hybrid and tri-hybrid nanofluids. The nano-composition of graphene oxide ( Go) and cobalt ( Co) is used in the amalgamation of hybrid nanofluid Go-Co/H2O, whereas the addition of zirconium oxide ( ZrO2) in this mixture gives rise to the ternary Go-Co-ZrO2/H2O hybrid nanofluid. The activation energy and viscous dissipation terms are also amended in the governing equations. The mathematical framework consists of a complex natured dynamical system. However, a numerical algorithm based on finite-difference discretization is developed which can solve the system numerically via the MATLAB software. A comparison with the existing literature is provided in order to validate the numerical procedure. From the outcomes, it is noticed that the temperature of hybrid as well as tri-hybrid nanofuid increases rapidly with change in concentration of zirconium oxide and cobalt. Temperature increases up to 20% by taking 0.1 volume fraction of both zirconium oxide and cobalt. Porous medium and activation energy resist the flow and concentration respectively. A comparative judgment evidently reveals that tri-hybrid Go-Co-ZrO2/H2O nanofluid has a substantial effect on temperature as equated to hybrid or pure nanofluid.

CFD analysis of paraffin-based hybrid (Co–Au) and trihybrid (Co–Au–ZrO2) nanofluid flow through a porous medium

Abstract Ternary hybrid nanofluids possess improved thermal characteristics, enhanced stability, better physical strength, and multi-functionality as compared to hybrid or usual nanofluids. The aim of the ongoing study is to explore the novel thermal attributes of hybrid and trihybrid nanofluids through a porous medium. Whereas the nano-composition of cobalt (Co), gold (Au), and zirconium oxide (ZrO2) make amalgamation in the paraffin (Pfin) which is a base fluid. This nano-composition of the proposed nanoparticles, specifically, subject to the base fluid Pfin has not been interpreted before. The analysis not only covers the features of trihybrid nanofluids (Co–Au–ZrO2–Pfin) but it also describes the characteristics of hybrid (Co–Au–Pfin) as well as pure nanofluids (Co–Pfin). An efficient numerical algorithm is developed for which the numerical simulations are carried out. The approximations are performed in MATLAB software using “Successive under Relaxation (SUR)” technique. A comparison, under certain limiting conditions, with the established results appraises the efficiency of the numerical code. The outcomes evidently designate that temperature raises with the change in thermal radiation and volume fraction of gold and zirconium oxide in either case of pure, hybrid, or ternary nanofluids. The concentration ϕ 3 {\phi }_{3} of ZrO2 has a significant impact on Nusselt number rather than the concentration ϕ 1 {\phi }_{1} of cobalt and ϕ 2 {\phi }_{2} of gold. It has been comparatively noticed that the ternary nanofluids (Co–Au–ZrO2–Pfin) portray embellished and improvised thermal characteristics as compared to the other two cases.

A novel numerical note on the enhanced thermal features of water-ethylene glycol mixture due to hybrid nanoparticles (MnZnFe2O4 – Ag) over a magnetized stretching surface

In this article, we presented a numerical solution of steady-state magnetohydrodynamic (MHD) flow of an incompressible, electrically conducting Casson hybrid nanofluid through a stretching surface under the incitement of viscous dissipation, heat generation and induced magnetism. A viscous mixture of water and ethylene glycol ( W : E G = 60 % : 40 % ) is considered as a base fluid. Enhanced thermal aspects of the working fluid due to suspended manganese zinc ferrite ( MnZnFe 2 O 4 ) and silver ( Ag ) nanoparticles are analyzed by successive over relaxation iterative method. A self-similar procedure is adopted to obtain dimensionless system of governing equations. Order reduction and finite differences discretization of nonlinear coupled differential equations lead to the approximate solution of proposed problem. Impacts of various dominant parameters on the hybridized Casson fluid are examined through the graphs sketched for the functions of velocity, temperature, and induced magnetism. Skin friction coefficient and thermal transfer characteristics at the stretching surface have been simultaneously observed via tabular data prepared for pure nanofluid ( Ag-WEG ) as well as for hybrid nanofluid ( MnZnFe 2 O 4 -Ag/WEG ). It is perceived that induced magnetic field tends to decline the Nusselt number while exhibits a significant growth in the surface drag. Moreover, a significant enhancement in temperature of working fluid has been observed due to Eckert number and heat generation parameter. This decisive role of enhanced thermal features will help to improve industrial growth, waste-water treatment, and automobiles engine efficiency.

Investigation of the Lubrication Performance of γ-Al2O3/ZnO Hybrid Nanofluids for Titanium Alloy

Titanium alloys are difficult to machine and have poor tribological properties. This paper investigates the lubricating performance of γ-Al2O3/ZnO hybrid nanofluids for Ti-6Al-4V. Pure and hybrid nanofluids are compared, and the effects of γ-Al2O3/ZnO ratios are studied. The results show that γ-Al2O3/ZnO hybrid nanofluids outperform pure nanofluids in terms of lower friction coefficients and better surface quality. Moreover, the hybrid nanofluid with a mass ratio of Al2O3 to ZnO of 2:1 demonstrates the best lubrication performance with a reduced friction coefficient of up to 22.1% compared to the base solution, resulting in improved surface quality. Al2O3 nanoparticles can adhere to the surface of ZnO nanoparticles and work as a coating, which further enhances the lubrication performance of the water-based nanofluid.

Microrotating chemically reactive hybrid nanomaterial in a high porous medium influenced by Cattaneo-Christov double diffusion and non-linear slip

ABSTRACT A simultaneous heat and mass transfer due to microrotating Darcy-Forchheimer flow of hybrid nanofluid over a moving thin needle is investigated. Darcy-Forchheimer medium accommodating hybrid nanofluid flow yields greater heat transfer rate, thereby leading to greater mass transfer rate over thin needle in industrial applications such as blood flow problems, aerodynamics, transportation, coating of wires, lubrication, and geothermal power generation. The thermophoresis and Brownian motion phenomena are introduced to enrich thermal treatment. Heat and mass transfer are accompanied by Cattaneo-Christov heat and mass flux. The hybrid nanofluid is radiative and dissipative in nature. Arrhenius pre-exponential factor law is introduced. Entropy generation analysis is carried out. The 4th order Runge-Kutta method along with shooting technique is devised to get requisite numerical solution of the transformed non-dimensional system of equations. Darcy-Forchheimer effect to simultaneous heat and mass transfer of microrotating hybrid nanofluid flow over thin needle subject to non-linear slip is the novelty of present study which is beyond of previous investigations. Rise in Forchheimer number (strengthening Darcy Forchheimer medium) leads to surface viscous drag decreases by 11.11% for hybrid nanofluid and 10.78% for pure nanofluid indicating the control of momentum transfer, thereby regulating heat transfer rate effectively.

Thermal attributes of hybrid (MWCNT-NiZnFe2O4) nanofluid flow having motile microbes and activation energy: A computational approach

Hybrid nanofluids provide better thermal network, mechanical resistance, good aspect ratio and thermal conductivity rather than usual/mono nanofluids. The hybrid nano-composition of multi-wall carbon nanotubes and nickel zinc ferrites possesses superior thermal properties and embellished heat transfer characteristics. The main concern, in this paper, is to examine the novel thermal aspects of water based pure nanofluid (MWCNTs) and hybrid nanofluid (MWCNTs-NiZnFe2O4). The prominent effects of viscous dissipation, motile gyrotactic microorganisms and activation energy have also been taken into account. The other aspect of the study is also to interpret the flow features of hybrid nanofluids subject to Darcy-Forchheimer medium. The characteristics of both hybrid and usual case of nanofluids are covered in this analysis. The governing model problem comprising of coupled and highly non-linear system of equations is treated numerically via a persuasive numerical technique named “Successive over Relaxation” method. A numerical comparison not only validates the code but also found to be in a good correlation with the earlier ones. It can be deduced from the outcomes of the present study that higher levels of Peclet number cause a decrease in the density distribution of motile microorganisms. For the higher values of Forchheimer parameter, lower will be the velocity of fluid and higher will be the shear stress in either, pure or hybrid, case of nanofluids.

Thermal impact of hybrid nanofluid due to inclined oscillatory porous surface with thermo-diffusion features

Owing to improved thermal efficiencies of hybrid nanomaterials, various applications of such tiny particles are claimed in enhancing thermal impact in heat transfer phenomenon, improving the efficiencies of solar collectors, thermal management systems and different industrial processes. Following to such motivations in mind, this research communicates the thermal impact of hybrid nanofluid with utilization of different nanoparticles due to porous infinite plate. The characterization of hybrid nanoparticles is observed with interaction of copper (Cu), aluminium oxide (Al2O3), titanium oxide (TiO2) with water base fluid The phenomenon is supported with thermal radiation phenomenon. The porous medium with uniform permeability is considered within flow regime. The onset of chemical reaction is attributed in concentration equations. The closed form solution is obtained via analytical procedure. The thermal assessment of nanoparticles in flow regime with effect of different parameters is considered. The comparative thermal observations are reported for pure nanofluid and with different nanoparticles.

Analysis of pure nanofluid (GO/engine oil) and hybrid nanofluid (GO–Fe3O4/engine oil): Novel thermal and magnetic features

Abstract Hybrid nanofluids can provide better physical strength, thermal conductivity, and mechanical resistance in many thermodynamic systems than pure nanofluids. To establish the novel results, using superior types of hybrid nanoparticles like graphene oxide (GO) and iron oxide (Fe3O4) is the main focus of recent work. This study investigates the innovative thermal and magnetic features of both pure nanofluid GO/engine oil (EO) and hybrid nanofluid GO–Fe3O4 /EO under the simultaneous effects of induced as well as applied magnetic field. The chemical reaction phenomenon together with activation energy has also been taken into account. A novel algorithm based on order reduction and finite difference discretization is developed in order to numerically treat the problem. The efficiency of the code is appraised by a numerical comparison which is found to be in a good correlation with the existing results. From the consequences of this study, it is deduced that the reduction in induced magnetic field and fluid’s velocity (in case of either pure or hybrid nanofluid) is associated with the enlarging values of magnetic Prandtl number and induced magnetic field parameter. Further, activation energy is responsible for enhancement in concentration. The hybrid nano-composition of GO–Fe3O4/EO can provide the thermal stability, prevent the corrosion and make the liquid to stay in high temperature.

Novel thermal aspects of hybrid nanoparticles Cu-TiO2 in the flow of ethylene glycol

Hybrid nanoparticles possess better chemical stability, mechanical resistance, thermal conductivity, physical strength and so forth as equated to pure nanoparticles. The present work describes the novel features of hybrid nanoparticles such as Titanium oxide (TiO2) and Copper (Cu) in the flow of Ethylene glycol (EG) under the induced magnetic field environment. The analysis covers the features of both pure nanofluid Cu/EG and hybrid nanofluid Cu-TiO2/EG. The concentration equation is amended by the activation energy term. The amalgamation of Cu-TiO2/EG exhibits improved and embellished thermal characteristics. A persuasive numerical technique named “Successive over Relaxation” is used to attain the numerical solutions of the problem. The outcomes have also been assessed in a comparison and, found to be in a good connection with the earlier ones. The significant impacts of prime parameters are physically interpreted and deliberated through graphs and tables. Heat transfer rate has been convincingly improved by pouring hybrid nano-composites (Cu-TiO2) into the base fluid Ethylene glycol (EG). From the outcomes of the problem, it is disclosed that higher the activation energy Ee lower will be the mass transfer rate and higher will be the concentration distribution.

Numerical simulation of three-dimensional thermo-solutal convection of micropolar multi-walled carbon nanotubes water nanofluid stabilized by lignin and sodium polycarboxylate

A computational analysis has been performed in this study to solve three-dimensional thermo-solutal natural convection in a differentially heated cubical enclosure filled with micropolar CNT/water nanofluid stabilized by two types of surfactants lignin and sodium polycarboxylate. The work is carried out for different pertinent parameters as Rayleigh number (104 \(\le\) Ra \(\le\) 106), micropolar parameter (0 \(\le\) K \(\le\) 10), buoyancy ratio (−1 \(\le\) N \(\le\) 0) and nanoparticles’s volume fraction (0.0055% \(\le \varphi \le\) 0.557%). It is observed that the heat and mass transfer rates are lower for a micropolar nanofluid model when compared to the pure nanofluid model. In fact, the enhancement of micropolar parameter results a decrease in average Nusselt and Sherwood numbers. The use of lignin as a surfactant ameliorates heat and mass transfer rate and nanofluid flow better than the use of sodium polycarboxylate as a surfactant. The nanoparticles volume fraction can be used as a control element for heat rate and fluid flow. Thus, for a nanoparticles volume concentration less than the critical value, the flow intensity is ameliorated and is deteriorated when it exceeds this value.

Three-Dimensional Numerical Analysis on Performance Enhancement of Micropolar Hybrid Nanofluid in Comparison with Simple Nanofluid

The objectives of the present research work are the three-dimensional computational analysis and predictions on double-diffusive natural convection in a cubic cavity filled with Cu–Al2O3/water micropolar hybrid nanofluid. The governing equations are carefully modified employing vorticity–vector potential formulation and are solved by the finite volume method. Performance enhancement of Cu–Al2O3/water micropolar hybrid nanofluid is judiciously compared with the Cu/water simple nanofluid. Besides, the influences of concentration of nanoparticles, Rayleigh number, buoyancy ratio, and micropolar vortex parameter on the flow field and heat transfer are critically analyzed. The results show that heat and mass transfer rates are lower for a micropolar nanofluid model when compared to the pure nanofluid model. The hybrid micropolar nanofluid displays more heat and mass transfer rates for thermal buoyancy-dominated zones when compared with traditional nanofluid. Conversely, the heat and mass transfer rates are decreased when using micropolar hybrid nanofluid for the solutal-dominated regime. The enhancement of micropolar viscosity parameter results in a decrease of average Nusselt and Sherwood numbers which are more perceptible in the thermal buoyancy-dominated flow.

Experimental investigation of rheological properties and thermal conductivity of SiO2\u2013P25 TiO2 hybrid nanofluids

Over many years, great efforts have been made to develop new fluids for heat transfer applications. In this paper, the thermal conductivity (TC) and viscosity of SiO2–P25 TiO2 (SiO2–P25) hybrid nanofluids were investigated for different nanoparticle volume concentrations (0.5, 1.0 and 1.5 vol%) at five various temperatures (20, 30, 40, 50 and 60 °C). The mixture ratio (SiO2:P25) in all prepared hybrid nanofluids was 1:1. Besides, pure SiO2, P25 nanofluids were prepared with the same concentrations for comparison with the hybrid nanofluids. The base fluid used for the preparation of nanofluids was a mixture of deionized water and ethylene glycol at a ratio of 5:1. Before preparing the nanofluids, the nanoparticles were analyzed with energy-dispersive X-ray analysis, scanning electron microscope, X-ray powder diffraction, and Fourier transform infrared spectroscopy. The zeta potentials of the prepared nanofluids except SiO2 nanofluids were above 30 mV. These nanofluids were visually observed for stability in many days. The TC enhancement of the hybrid nanofluid was higher than the pure nanofluid. In particular, with 1.0 vol% concentration, the maximum enhancement of SiO2, P25 and SiO2–P25 nanofluids were 7.5%, 9.9% and 10.5%, respectively. The rheology of the nanofluids was Newtonian. The viscosity increment of SiO2, P25 and hybrid nanofluids were 19%, 32% and 24% with 0.5 vol% concentration. A new correlation was developed for the TC and dynamic viscosity of SiO2–P25 hybrid nanofluid.

On Simulation of Double-Diffusive Natural Convection in a Micropolar Nanofluid Filled Cubic Cavity

The heat and mass transfer characteristics of a micropolar nanofluid-filled cubic cavity are investigated with different types of nanoparticles (Al2O3, TiO2, Cu and Ag). Pure water is assumed as the base fluid. The governing equations are simplified by means of vorticity-vector potential formulation and subsequently solved numerically using the finite volume method. The influences of relevant parameters on heat and mass transfer characteristics are well explored and the results show that for the micropolar nanofluid model both heat and mass transfer rates and the three-dimensional character of the flow are smaller compared with that of a pure nanofluid model. It is also found that the rate of heat and mass transfer decreases with an increase in vortex viscosity parameters as well as volume fractions. The enhancement in the volume fraction of nanoparticles weakens both flow strength and three-dimensional nature of the flow, which are more prominent in the thermal buoyancy dominated flow. The average Nusselt and Sherwood numbers decrease with the increase in the volume fraction of nanoparticles resulting in a significant enhancement in thermal properties of nanofluids with elevated heat and mass transport features. The effects of type of nanoparticles on the rate of heat and mass transfer and flow structure are analyzed.

Synergistic influence of nanoparticles and surfactants on interfacial tension reduction, wettability alteration and stabilization of oil-in-water emulsion

In this study, the synergistic interaction of nanoparticles and surfactants were explored for oil-water interfacial tension (IFT) reduction, alteration of rock wettability, and stabilization of oil-in-water emulsion. The interfacial properties were investigated using drop-shape analyzer (DSA 25) while the pore scale visualization studies were conducted using the etched glass micromodels. The most stable surfactant-stabilized emulsion was formed in presence of cetyltrimethylammonium bromide (CTAB) while the order of increasing emulsion stability in presence of nanoparticles was obtained as follows: carbon nanotubes >copper oxide> silicon dioxide> aluminum oxide > titanium dioxide. Compared to pure nanofluids or surfactant solutions, the nanoparticles-surfactant solutions demonstrated promising tendency for significant reduction in oil-water interfacial tension and alteration of rock wetting properties. Specifically, the carbon nanotubes (CN) based nanofluids, reduced the contact angle of the rock from 68.73° to 65.5° (4.7%) while the Triton X-100 (TX 100) and CN-TX100 solutions reduced the contact angles to 10.65° (84.5%) and 7.0° (89.8%) respectively. The dominant mechanism of resident oil mobilization from the micro and dead-end pores was identified as emulsification-entrainment. A correlation exists between influence of nanoparticles-surfactant solutions on interfacial properties and resident oil mobilization from the micro and dead-end pores. The CN-CTAB solution that was the most effective in mobilization of the resident oil from the micro and dead-end pores significantly reduced the crude oil-water IFT to 0.63 mN/m. The mechanisms of IFT reduction, wetting properties alteration, as well as emulsion stabilization have been identified as the orientation of the particles at the interface and the electrostatic interaction between the nanoparticles and surfactant molecules. These procedures could be exploited to achieve significant reduction in IFT, rock wettability alteration and emulsion stabilization than could be achieved using pure nanofluids or surfactant solutions only.

Magnetic Field Effect on the Double Diffusive Natural Convection in Three-Dimensional Cavity Filled with Micropolar Nanofluid

This article presents a three-dimensional numerical investigation of heat and mass transfers and fluid flow in a cavity filled with an Al2O3/water micropolar fluid under uniform magnetic field. To solve the governing non-dimensional equations, Finite Volume Method (FVM) based on 3-D vorticity-vector potential formulation has been employed. The effects of various parameters such as buoyancy ratio (−2 ≤ N ≤ 0), Rayleigh number (103 ≤ Ra ≤ 105), Hartmann number (0≤ Ha≤ 60), nanoparticles volume fraction (0 ≤ φ ≤ 0.06) and micropolar material parameter (0≤ K≤ 5) on flow structure and on heat and mass transfers are presented. The results illustrate that for the micropolar nanofluid model, both heat and mass transfer rates and three-dimensional character of the flow are smaller when compared with the pure nanofluid model. It is also observed that increase and decrease in heat and mass transfer rates is experienced due to increase in Rayleigh number and Hartmann number, respectively. It is also noted that increase in vortex viscosity parameter reduces the average heat and mass transfer rates and is more evident when the magnetic field is imposed. Combined effects of magnetic field and nanoparticles volume fraction on heat and mass transfers are also explored.

Contribution of hybrid Al2O3-water nanofluid and PCM suspension to augment thermal performance of coolant in a minichannel heat sink

The hybrid suspensions may offer better thermal efficacy than the addition of single type of additives. In this work, we attempted to investigate the simultaneous presence of microencapsulated phase change material (MEPCM) particles and Al2O3 nanoparticles dispersed in the base fluid (ultra-pure Milli-Q water) as a coolant in a minichannel heat sink. The heat sink used in this research had the dimensions of 1 × 1.5 × 50 mm in width, height, and length. The Reynolds number of the coolant ranged from 133 to 1515 in the presence of various concentrations of additives from 2 to 10 wt%. The results revealed that the implementation of the hybrid suspension can significantly improve the heat transportation in the minichannel heat sink (Mini-CHS) compared to the base fluid, due to the cooperative contributions of the superb thermal conductivity of nanoparticles and the latent heat adsorption by phase change particles. However, the performance of the hybrid suspension was highly dependent on the Reynolds number. For instance, it was found that the pure nanofluid outperforms the hybrid suspension at high Reynolds number. The hybrid suspension can effectively offer better performance by wisely adjusting the Reynolds number, and concentrations of nanoparticles and MEPCM particles for a given heat flux.

Two-Phase Analysis on the Conjugate Heat Transfer Performance of Microchannel With Cu, Al, SWCNT, and Hybrid Nanofluids

This numerical study has been carried out by developing two-phase mixture model with conjugate heat transfer. Pure and hybrid nanofluids (HyNF) with particle as well as base fluid hybridization are used in analyzing the performance of microchannel under forced convection laminar flow. The flow as well as heat transfer characteristics of pure water, copper (Cu), aluminum (Al), single-walled carbon nanotube (SWCNT), and hybrid (Cu + Al, water + methanol) nanofluids with various nanoparticle volume concentrations at different Reynolds numbers are reported. Sphericity-based effective thermal conductivity evaluation is considered in the case of SWCNT nanofluids by using volume and surface area of nanotubes. A significant enhancement in the average Nusselt number is observed numerically for both pure and hybrid nanofluids. Pure nanofluids such as Al, Cu, and SWCNT with 3 vol % nanoparticle concentration enhanced the average Nusselt number by 21.09%, 32.46%, and 71.25% in comparison with pure water at Re = 600. Whereas, in the case of hybrid nanofluids such as 3 vol % HyNF (0.6% Cu + 2.4% Al) and 3 vol % SWCNT (20% Me + 80% PW), the enhancement in average Nusselt number is observed to be 23.38% and 46.43% in comparison with pure water at Re = 600. The study presents three equivalent combinations of nanofluids (1 vol % Cu and 0.5 vol % SWCNT), (2 vol % Cu, 1 vol % SWCNT and 3 vol % HyNF (0.6% Cu + 2.4% Al)) as well as (2 vol % SWCNT and 3 vol % SWCNT (20% Me + 80% PW)) that provides a better switching option in choosing efficient working fluid with minimum cost based on cooling requirement. The study also shows that by dispersing SWCNT nanoparticles, one can enhance the heat transfer characteristics of base fluid containing methanol as antifreeze. The conduction phenomena of solid region cause the interface temperature between solid as well as fluid regions to increase along the length of the microchannel. The developed numerical model is validated with the numerical and experimental results available in the literature.

On laminar convective cooling performance of hybrid water-based suspensions of Al 2O 3 nanoparticles and MEPCM particles in a circular tube

Laminar forced convection of a hybrid water-based suspension of Al 2O 3 nanoparticles and microencapsulated phase change material (MEPCM) particles through a circular tube was investigated experimentally. In addition, an integral energy balance with scaling estimation is presented to elucidate influences of thermal properties of the hybrid suspension on its internal convection effectiveness. Experimental results show considerable enhancement in cooling effectiveness of the hybrid suspension over the pure PCM suspension, nanofluid, or water. However, the convection efficacy of utilizing the hybrid suspension appears severely outweighed by pressure drop penalty from its drastically increased viscosity with respect to the pure PCM suspension or the pure nanofluid.