Effect Of Hybrid Nanoparticles Research Articles

Insight into the bidirectional dynamics of hyperbolic tangent hybrid nanomaterial subject to Nield’s conditions using numerical approach

A hyperbolic tangent fluid model characterized by shear rate dependent viscosity together with the effects of hybrid nanoparticles, Brownian motion, thermo-diffusion, and Nield’s conditions, is utilized for thermal enhancement purpose. Five percent copper nanoparticles and twenty percent alumina nanoparticles are submerged into ethylene glycol with the parametric influence of tangent hyperbolic fluid to obtain the tangent hyperbolic hybrid nano suspension. Numerical solutions of the nondimensionalized conservation laws are found by the Keller-box method. The influence of various parametric factors on velocity, temperature, concentration, Nusselt number, and Sherwood number has been discussed. A constant Nusselt number is noted with the influence of Nield’s constraints. A 90% increase in thermal conductivity is achieved by dispersing 5% copper and 20% alumina nanoparticles into the ethylene glycol with the influence of hyperbolic tangent fluid. The error and convergence analysis of the numerical solution have been discussed, along with the validation of the obtained numerical results.

Analysis of the heat transfer enhancement in water-based micropolar hybrid nanofluid flow over a vertical flat surface

Abstract This article presented micropolar hybrid nanofluid flow comprising copper and alumina nanoparticles over a flat sheet. The mixed convection phenomenon is studied under the effect of gravity. Some additional forces such as magnetic field, thermal radiation, Eckert number, heat source, and thermal slip condition are adopted in this analysis. The leading equations are transformed into dimensionless format by employing appropriate variables and then evaluated by homotopy analysis method (HAM). The obtained results are compared with published results and found a good agreement with those published results. Also, the results of HAM are compared with those of numerical method and found a good agreement as well. The fluctuations within the flow profiles are showcased utilizing figures and tables, followed by an in-depth discussion and analysis. The outcomes of this work show that the higher volume fractions of copper and alumina nanoparticles improved the hybrid nanofluid viscosity, which results in the augmenting variation in the velocity profiles. The higher volume fractions of copper and alumina nanoparticles improved the hybrid nanofluid thermal conductivity, which results in the augmenting variation in thermal distribution. The growing mixed convection factor amplifies the buoyancy force toward the stagnation point flow, which enlarges the velocity panel. The effects of hybrid nanoparticles (Cu-Al2O3/water) at the surface are smaller on friction force and larger in case of thermal flow rate when compared to the nanofluids (Cu/water and Al2O3/water).

Flow and irreversible mechanism of pure and hybridized non-Newtonian nanofluids through elastic surfaces with melting effects

Abstract The significance of nanofluid research in nanotechnology, pharmaceutical, drug delivery, food preparation, and chemotherapy employing single- and two-phase nanofluid models has drawn the attention of researchers. The Tiwari–Das model does not capture the diffusion and random movement of nanoparticles (NPs) when they are injected into complex functional fluids. In order to fix the peculiar behavior of NPs, more complex models like the Buongiorno model are coupled with the single-phase model. To examine the heat-mass transfer attributes of nanofluids, a single- and two-phase mixture model is coupled for the first time. The effect of hybrid NPs on the hemodynamic properties of the blood flow through a stretched surface with interface slip in the neighborhood of the stagnation point is examined. Due to their significance in medicinal uses and nominal toxicity, blood is loaded with zinc–iron ( ZnO − F e 2 O 3 ) {\rm{ZnO}}\left-{\rm{F}}{{\rm{e}}}_{2}{{\rm{O}}}_{3}) NPs. However, blood is speculated to have the hematocrit viscosity of the Powell–Eyring fluid. The single-phase model predicts an improvement in heat transport due to an increased volumetric friction of NPs, while the two-phase models provide closer estimates of heat-mass transfer due to Brownian and thermophoretic phenomena. Entropy evaluation predicts the details of irreversibility. The mathematical structures are effectively solved with a Runge–Kutta fourth-order algorithm along with a shooting mechanism. The Eyring–Powell parameters decrease the drag coefficient and mass/thermal transport rate. A higher estimation of the slip, material, and magnetic parameters decreases the flow behavior. The Bejan number increases with the diffusion parameter and decreases as the magnetic and Brinkman numbers increase. The effect of iron oxide ( F e 2 O 3 ) \left({\rm{F}}{{\rm{e}}}_{2}{{\rm{O}}}_{3}) is observed to be dominant.

Nano-silika ve GNP Hibrit Nanoparçacık Takviyeli Tek Bindirmeli Bağlantıların Kesme ve Kırılma Özellikleri

In the current study, the effects of hybrid nanoparticles on the shear and fracture behaviours of adhesively bonded single lap joints (SLJs) using Aluminum substrates were investigated. To this aim, nano-silica and graphene nanoplatelet (GNP) particles were used as filler materials in Araldite 2014-2 epoxy-based adhesive. The SLJ samples prepared at seven different configurations were subjected to lap shear tests. Additionally, macro and SEM views taken from damaged surfaces of the samples were examined to understand the influence of nanoparticle addition on the fracture characteristics of the joints. The experimental findings showed that all nanoparticle-doped samples, whether single or hybrid, exhibited remarkable improvements in shear strength compared to pure ones. The maximum improvements were obtained from the H2 sample having 1 wt.% nano-silica and 0.5 wt.% GNP. The maximum shear strength was 13.62 MPa which was 213% higher than pure samples (4.35 MPa). It was determined that some toughening mechanisms such as crack deviation, crack bridging and plastic void formations had a crucial role in the enhancements of the samples. However, higher amounts of nanoparticle inclusion such as H4 (1.5 wt.% nano-silica+1 wt.% GNP) showed a decrease in shear strength, compared to the maximum one, due to the material degradation caused by agglomerations. In conclusion, nano-silica and GNP particles proved they could be used together by exhibiting a synergetic effect in the adhesive joints.

Effects of Hybrid Nanoparticles on Thermophysical Property of Cu-TiO2 Embedded Palmitic Phase Change Material for Energy Storage Applications

This experimental investigation studies the thermo physical effects of Cu-TiO2 hybrid nanoparticles embedded into organic PCM (palmitic acid) for energy storage applications. This Nano Embedded PCM (NEPCM) or Hybrid Nano composite (HNPCM) is used for heating, cooling and numerous energy storage applications. This hybrid nano composite mixture was synthesized by mixing different weight percentage Cu-TiO2 hybrid nanoparticles in palmitic acid. The dispersion is facilitated with the help of ultrasonicator. The hybrid nanoparticles were characterized with Scanning Electron Microscope. Fourier Transform Infrared spectroscopy analysis was used to determine the chemical stability and composition of composite mixture. LFA 467 flash diffusivity apparatus was used to measure the increase in thermal conductivity. The test results suggest that, by embedding HyNC into pure PCM. It has credited for achieving chemical stability, concurring phase transition temperature, favourable latent heat. HyNC particles have effectively enhanced the thermal conductivity of the PCMs by 52% without sacrificing chemical stability or thermal degradation. This result shows that the addition of HyNC into the palmitic acid increases the solidification and melting time, thus confirming the enhancement in thermal conductivity. This enhanced thermal characteristic makes HNPCM’s as a potential candidate for energy storage and heat transfer applications.

Thermal Convective Instabilities and Chaos in a Rotating Hybrid Nanofluid Layer with Cattaneo–Christov Heat Flux Model

The linear and nonlinear dynamics of thermal convection of a rotating hybrid nanofluid layer heated from below with the Cattaneo–Christov heat flux model are studied in this paper. Starting from the flow equations of a hybrid nanofluid and exploiting the free boundary conditions, the analytical expressions of the stationary and oscillatory Rayleigh numbers of the base fluid are determined as a function of the dimensionless parameters of the heat transfer fluid and the thermophysical properties of the hybrid nanofluid. The effects of hybrid nanoparticles and Taylor number on the onset of stationary convection in the base fluid are investigated graphically. Then, a numerical study of the transition from natural convection to chaotic behaviour of the hybrid nanofluid is made using the truncated Galerkin approximation. This approximation allowed us to find a novel six-dimensional nonlinear system depending on the parameters of the base fluid and the thermophysical properties of the hybrid nanofluid that can be reduced to five, four, or three dimensions when we tend some parameters to zero. The different results showed that the addition of hybrid nanoparticles (alumina-copper) to a thermal fluid (water) subjected to the rotation force in the presence or absence of the thermal relaxation time allows control of the chaotic convection in the base fluid. On the other hand, the increase of the rescaled Taylor number and the Cattaneo number widens the domain of chaos in the hybrid nanofluid with the increase of the rescaled Rayleigh number of the base fluid.

Effect of hybrid nanoparticles on conjugate mixed convection of a viscoplastic fluid in a ventilated enclosure with wall mounted heated block

We consider the thermal performance due to mixed convection and conjugate heat transfer of a Al2O3- Cu/viscoplastic hybrid nanofluid in a ventilated enclosure. A cold viscoplastic hybrid nanofluid is injected through the inlet port placed at the lower left corner of the enclosure and an outlet is placed at lower right corner. A heated solid obstacle is mounted at the bottom wall of the enclosure and the left wall of the enclosure is considered to be uniformly heated. The viscoplastic nanofluid is modeled as the Casson fluid, in which the plastic viscosity is considered to be temperature dependent. Nanoparticles mass flux due to both Brownian and thermophoretic diffusion along with convection is taken into account. The Corcione model for the thermal conductivity and viscosity of the hybrid nanofluid is adopted. The presence of the heated obstacle at the lower wall induces a recirculating vortex above it, which reduces the heat transfer from the enclosure. This vortex disappears when higher range of Reynolds number is considered. Our results show that the inclusion of Cu-nanoparticles in the Al2O3-viscoplastic fluid manifests the heat transfer. The yield stress of the fluid reduces the heat transfer but enhances the entropy generation. The thermal performance of the system is evaluated by presenting the heat transfer to entropy generation ratio. An enhancement of the solid-to-fluid conductivity ratio intensifies the heat transfer as well as entropy generation. Hybrid nanofluid enhances both heat transfer as well as entropy generation with the rate of heat transfer higher than the rate of entropy generation. A comparison with the corresponding homogeneous model is provided to analyze the effect of slip velocity created by Brownian diffusion and thermophoresis of nanoparticles.

Computational biomedical simulations of hybrid nanoparticles ([formula omitted] blood-mediated) transport in a stenosed and aneurysmal curved artery with heat and mass transfer: Hematocrit dependent viscosity approach

In the present study, effects of hybrid nanoparticles (Au-Al2O3/blood) on hemodynamical characteristics of unsteady blood flow through a curved artery with stenosis and aneurysm have been analysed. Blood viscosity is assumed as hematocrit-dependent viscosity. The Crank-Nicolson method is applied to solve governing equations with 10-6 tolerance in each iteration. The acquired results for both stenotic and aneurysm segments are presented graphically and have been examined for various physical parameters. It is noted that with an increment in volume fraction of gold (Au) nanoparticles, the velocity profile rises, while, reverse effect is noticed for the volume fraction of Aluminium Oxide (Al2O3) nanoparticles. It is also observed that hybrid nanoparticles may help to control the blood velocity and temperature, which allow the surgeons to readjust it as and when required. The current findings are in good agreement with recent outcomes in previous research studies. The motive of this research is to provide a mathematical analysis of some diseases conditions, which can be helpful in the process of diagnosis and treatment related to the problems of plaque deposition and aneurysm in cardiovascular disorders without surgery, reduction in medical expenses, and minimizing post-surgical effects. Present study also has various applications in the treatment of a variety of pathological conditions such as tumors, removal of blood clots, brain aneurysms, infections. It can be utilized for controlling the blood flow rate, resistance to flow, wall shear stress, and heating effect during surgical processes by varying the strength of the applied magnetic field, the volume fraction of nanoparticles, radiation effect, etc.

Numerical study on heat and mass transport enhancement in MHD Williamson fluid via hybrid nanoparticles

Fundamental laws are used for modeling of transport characteristics in Williamson fluid with Cu and Al2O3. Models are solved numerically using the finite element method (FEM). study is conducted on the effects of hybrid nanoparticles on heat and mass transfer during homogeneous and heterogeneous chemical reactions. The Williamson parameter can play significant influence on momentum transport. Based on simulations, the Lorentz force for the flow of Cu-Al2O3–Williamson fluid is greater than the Lorentz force acting on Cu-Williamson fluid. Thus momentum BL thickness for Cu-Al2O3-Williamson fluid is less than that for the flow of Cu-Williamson fluid. An increase in curvature parameter makes the fluid to decelerate. However, this decelerating effect for flow of Cu-Williamson fluid is more than that in Cu-Al2O3– Williamson fluid. Mass transport in the fluid is slow down by an increase in when Schmidt number is increased. However, this decrease in transport of mass in Cu-Al2O3– Williamson fluid is greater than that in Cu-Williamson fluid. Concentration related to the products of species taking part in homogeneous-heterogeneous chemical reaction strength.

Effects of Heat Generation/Absorption on a Stagnation Point Flow Past a Stretching Sheet Carbon Nanotube Water-Based Hybrid Nanofluid with Newtonian Heating

This study investigates the mathematical modelling of heat generation/absorption effect on the convective flow of single wall carbon nanotube-copper (SWCNT-Cu)/water hybrid nanofluid towards a stagnation point past a stretching sheet with Newtonian heating. The set of governing equations in the form of non-linear partial differential equations are first transform using the similarity transformation technique then solved numerically by the Runge-Kutta-Fehlberg (RKF45) method in Maple software. The numerical solutions were obtained for the surface temperature, the heat transfer coefficient and the skin friction coefficient as well as the velocity and the temperature profiles. The features of the flow and heat transfer characteristics for various values of the stretching parameter, the conjugate parameter, the nanoparticle volume fraction parameter and the heat source/sink parameter are analyzed and discussed. It is found that effects of hybrid nanoparticles are more significant for lower stretching parameter and for large conjugate parameter values, as well as the heat generation/absorption.

Effect of hybrid nanoparticles on compression strength of recycled composite Zn –Al alloy

Abstract In the present study, different weight percentages of (SiC and BN) hybrid nanoparticles that reinforced by ZA alloy have successfully been fabricated through using a stir casting technique. The Hybrid nanoparticle effects on mechanical characteristics, such as compression strength and hardness, have been investigated. The scanning electron microscopy showed the microstructure of the composite. And, the results indicated the uniform distribution of (SiC and BN) hybrid nanoparticles in the Zn-Al matrix. Also, an optical microscope was used to analyze the microstructure, this showed a dendritic structure and reinforcement particles that disappeared uniformly in the matrix with the presence of agglomerate particles. The mechanical characterization results revealed that the hardness and compression increased with increasing the hybrid nanoparticle's percentage.

Effects of Cu–Ag hybrid nanoparticles on the momentum and thermal boundary layer flow over the wedge

In this work, the effects of hybrid nanoparticles on the momentum and thermal boundary layers as well as flow characteristics and thermal performance of the hybrid nanofluid are investigated over the wedge. The fluid in the enclosure is water containing hybrid nanoparticles Cu–Ag. The physical model of homogenous hybrid nanofluid is derived using the elementary equations of thermo-hydrodynamic and co-relation's model of a mixture that supports the effective physical features. The results are calculated to measure the effects of nanoparticle concentration on thermal and momentum boundary layers and displayed in graphs for discussions. In addition, the effects of nanoparticles concentration and different compositions of hybrid nanoparticles on temperature and velocity profiles, physical properties, skin friction, and convective heat transfer coefficient are deliberated through graphs and tables. To check its heat transfer performance, a comparison of hybrid nanofluid is made between the base fluid and single material nanofluids. It is found that the efficiency of hybrid nanofluids as a heat transfer fluid is much more than conventional fluids or single nanoparticles-based nanofluids. These results in terms of boundary layers phenomena, heat transfer performance, and temperature and velocity profiles under hybrid nanomaterial could help chemical engineers to design the critical equipment in a process industry such as heat exchangers and pumps and others.

Local thermal non-equilibrium analysis of conjugate free convection within a porous enclosure occupied with Ag–MgO hybrid nanofluid

Current investigation aims to analyze the conjugate free convection inside a porous square cavity occupied with Ag–MgO hybrid nanofluid using the local thermal non-equilibrium (LTNE) model. Hybrid nanofluids are a novel kind of enhanced working fluids, engineered with enhanced thermo-physical and chemical properties. Two solid walls located between the horizontal bounds in two sides of cavity play the role of a conductive interface between the hot and cold walls, and moreover, the top and bottom bounds have been insulated. The governing differential equations are obtained by Darcy model and then for better representation of the results, converted into a dimensionless form. The finite element method is utilized to solve the governing equations. To evaluate the correctness and accuracy of the results, comparisons have been performed between the outcomes of this work and the previously published results. The results indicate that using the hybrid nanoparticles decreases the flow strength and the heat transfer rate. The heat transfer rate augments when Rk rises and the flow strength augments when Ra grows. Enhancing the porosity increases strongly the size and strength of the vortex composed inside the porous medium. When Kr is low, the heat transfer rate is low and by increasing Kr, thermal fields become closer to each other. The effect of hybrid nanoparticles on thermal fields with the thinner solid walls is more than that the thicker ones. An increment in H eventuates the enhancement of heat transfer and hence, the thermal boundary layer thickness. By increasing the volume fraction of the hybrid nanoparticles, Nuhnf and Nus decrease in constant Ra. Besides, increase in Ra enhances the Nuhnf and Nus. For a certain d, the reduction of Nus due to using the hybrid nanoparticles is more than that for Nuhnf. The increment of d lessens Nuhnf for all values of Kr and has not specific trends for Nus. Utilizing hybrid nanoparticles decreases Nus (except d = 0.4), rises Nus when Kr 42. In constant d, increment of H, respectively, decreases and boosts Nuhnf and Nus. For all values of d, increment of e declines Nuhnf. In low value of d, the increase in e reduces Nus, whereas at higher values, Nus has continuously enhancing trend. For different values of d, the increase in e scrimps Nuhnf. The increment of d and also e, and H are, respectively, decreases and increases the heat transfer rate.

Melting of nanoparticles-enhanced phase-change materials in an enclosure: Effect of hybrid nanoparticles

The present paper studies the melting of nanoparticles-enhanced phase-change materials (NEPCM) in a square cavity using the finite element method. The enhancement is based on the hybrid nanofluid strategy. A linearized correlations procedure has been followed to determine the properties of the hybrid nanofluid. The Rayleigh, Prandtl, and Stefan numbers have been fixed at 108, 50, and 0.1, respectively. The left wall is kept at a higher temperature Th = 40 °C, the right wall is kept at a lower temperature Tc = 30 °C, while the horizontal walls are kept adiabatic. The enthalpy-porosity model is used to simulate the melting of the phase-change materials (PCM). The study is governed by tracing the liquid–solid interface by varying the total nanoparticles volume fraction ϕ = 0–5%, and four different sets of models parameters combinations (Nc, Nν) = (0,0), (5,18), (18,18), (18,5). The results have shown the consistency of the liquid–solid phase progress with the available experimental results, i.e. the melting process expedites when the enhancement in the thermal conductivity, which is characterized by Nc, is much greater than the enhancement of the dynamic viscosity. Compared with the available experimental data, hybrid nanoparticles composed of Mg–MgO demonstrate the best fusion performance.

Phase-change heat transfer in a cavity heated from below: The effect of utilizing single or hybrid nanoparticles as additives

Abstract The present study deals with the effects of hybrid nanoparticles on the melting process of a nano-enhanced phase-change material (NEPCM) inside an enclosure. The bottom side of the cavity is isothermal at a hot temperature while the top wall is isothermal at a cold temperature and the left and right walls are insulated. The governing partial differential equations are first non-dimensional form and then solved using the Galerkin finite element method. Some of the dimensionless parameters are kept constant such as the Prandtl number, the Rayleigh number, the Stefan number and the ratio between the thermal diffusivity of the solid and liquid phases while the volume fraction of nanoparticles, the conductivity and viscosity parameters, and the Fourier number are altered. It is found out that increasing the values of the nanoparticles volume fraction, viscosity and conductivity parameters leads to significant variations in the solid-liquid interface for large values of Fourier number. Moreover, increasing the conductivity parameter and decreasing the viscosity parameter at the same time can cause an augmentation in the liquid fraction.

Effect of hybrid nanoparticles on glass transition temperature of polymer nanocomposites

Changes in the glass transition temperatures of composites based on polystyrene and nanosized macromolecular nanostructures (molecular silicasols, dendrimers) are reported. Silicasols are nanosized particles consisting of a silica core and an ethyl phenyl shell; dendrimers are formed using a carbosilane core with ethyl phenyl end groups. It has been observed that the glass transition temperatures of the composites (Tgc) may be either above or below the glass transition temperature of polystyrene, depending on the size of the filler particles. A theoretical model based on the relation between the glass transition temperature and the configurational entropy of the composite, which satisfactorily describes the experimental dependence, was developed. It is found that the effect of the size of the hybrid nanoparticles on Tgc was determined using two factors. First, the presence of an organic layer on the surface of nanoparticles increases the number of degrees of freedom and the entropy of the system, thereby reducing Tgc. Second, the particles present in the polymer reduce the number of configuration states of macromolecules, which reduces the disorientation entropy. This effect leads to an increase Tgc. The competition between these two main factors determines the sign of the glass transition temperature deviation. The size of the particles and their organic surface layer play the key roles in the thermodynamic properties of the composites. POLYM. COMPOS., 37:1978–1990, 2016. © 2015 Society of Plastics Engineers