Values Of Nanoparticle Volume Fraction Research Articles

Significance of shape factor on magnetohydrodynamic buoyancy thin film flow of nanofluid over inclined sheet with slip condition: Irreversibility analysis

This work aims to examine the entropy production, heat transport, and dynamics of the unsteady thin film magnetohydrodynamic (MHD) flow of a nanofluid composed of alumina (Al2O3) and water. The fluid flow is seen to pass over an inclined sheet, taking into account the effects of buoyancy force, viscous dissipation, and joule heating. The system of partial differential equations (PDEs) is optimized under the boundary layer assumptions. Appropriate transformations are used to convert the governing partial differential equations (PDEs) and boundary conditions into dimensionless forms. Using MATLAB’s bvp4c code and a local non-similarity technique with up to second-degree truncation, we can obtain the findings of the enhanced model. The effect of multi-shape Al2O3 nanoparticles on flow, heat, and entropy-generating features is also investigated after the calculated results have been successfully aligned with published data. Mixed convection, nanoparticle volume percent, inclination angle, magnetic field intensity, mass suction, Eckert number, and Biot number are only a few of the governing parameters whose effects are graphically shown for selected values. As a result, the local Nusselt number and skin friction coefficient may be calculated. The skin friction and Nusselt number profiles exhibit a decreasing trend as the values of nanoparticle volume fraction ([Formula: see text]) magnetic [Formula: see text] and unsteadiness (A) increase toward mixed convection ([Formula: see text]). On the other hand, Nusselt number profile increases with increasing values of mass suction parameter [Formula: see text] The profiles of entropy generation and Bejan number show an upsurge as the values of the magnetic parameter [Formula: see text] and Brinkman number (Br) increase. Conversely, the entropy generation reduces with an increase in the temperature difference parameter [Formula: see text] and Bejan number increases.

Numerical solution of entropy generation in nanofluid flow through a surface with thermal radiation applications

The main purpose of this research is to investigate a mathematical model of nanofluid passing through a stretching sheet having titanium dioxide (TiO2), copper oxide (CuO), and carbon nanotubes (CNTs) as nanoparticles, and sodium alginate is used as a base fluid. The present model can be very useful for numerous fields like Bioengineering, science, and technology. The main reason for using titanium dioxide, copper oxide, and carbon nanotubes nanoparticles as nanomaterials they have many applications in several areas. Moreover, impacts of non-linear thermal radiation and entropy generations are taken into account. By utilizing the similarity transformation technique given system of governing PDEs are transformed into a set of ODE. Then dimensionless equations are numerically tackled via the Keller box method a built-in function in the computer tool MATLAB. To support the present study, physical and numerical interpretations of involved parameters against velocity, temperature, and entropy generation profiles are also presented. From the analysis it is concluded that the combination of a magnetic field and suction reduces the rate of fluid mobility due to the synchronization of the magnetic and electric fields generated by the formation of the Lorentz force. In addition, boosting the thermal radiation parameter raises the present authors' heat transfer rate. The velocity profile drops when the Casson parameter is raised, but the heat and entropy production profiles grow. When the porosity parameter is increased, the velocity profile falls, and the heat and entropy production profiles rise. Additionally the temperature distribution is boosted up with increasing the values of nanoparticles volume fraction. The good agreement between current results and published data is observed. It is necessary to investigate the thermophysical characteristics of the magnetite nanofluid (titanium dioxide, copper oxide, and carbon nanotubes-sodium alginate nanofluid) under various situations. The MHD flow of nanofluid is significant because of its wide range of industrial uses, including flows over the tips of rockets, planes, submarines, and oil tankers. The novelty of this work is to scrutinize the MHD flow and heat transfer analysis of a nanofluid towards a stretched surface. The features of magnetite nanofluid (titanium dioxide, copper oxide, and carbon nanotubes-sodium alginate nanofluid) under entropy generation, thermal radiation and velocity slip are investigated. All of this contributes to the work's uniqueness and novel.

Understanding the impact of magnetic dipole and variable viscosity on nanofluid flow characteristics over a stretching surface

The purpose of this research article is to investigate the impact of magnetic dipole on the flow of nano-fluids over the stretching surface with variable viscosity and thermal conductivity. Fluid fills the porous space. Heat transfer analysis is carried out in the presence of Newtonian heating. Water and ethylene glycol are used as base fluid while gamma alumina acts as a nanoparticle. System of ordinary differential equations is obtained by appropriate transformations. Numerical solutions are computed for the resulting nonlinear differential system by applying shooting method with RK-4 scheme. Impact of different parameters on the velocity and temperature profiles is examined. Computations for surface drag force and heat transfer rates are presented and examined for the influences of pertinent parameters. It is observed that fluid velocity reduces for larger viscosity parameter while opposite behavior is observed for temperature. Increasing values of ferro hydrodynamic interaction parameter and Curie temperature correspond to the enhancement in temperature. Surface drag force increases for larger values of nanoparticles volume fraction. Gamma alumina-ethylene glycol nano-fluid produce less surface drag force than gamma alumina-water nano-fluid. Heat transfer rate is increasing function of Prandtl number.

Nanofluid Flow Past a Static Wedge with Velocity Slip Condition

Nanofluids are known for their exceptional thermophysical properties, especially their thermal conductivity, which make them ideal for a number of heat transfer applications. In this study, the mixed convection nanofluid flow past a static wedge with the presence of velocity slip condition is investigated. The problem is governed by a system of partial differential equations which then transformed into a set of nonlinear ordinary differential equations by using an appropriate similarity transformation. The transformed governing equations are then solved numerically by using MATLAB bvp4c solver. Numerical solutions obtained are presented graphically in the form of velocity and temperature profiles for different values of nanoparticles volume fraction, wedge angle and velocity slip. It is found that the increasing values of the wedge angle parameter causes the velocity of the fluid to increase whereas the temperature profile of the nanofluid decreases, additionally it observed that velocity of the fluid increase when velocity slip is increased. The findings of this study provide valuable insights into optimizing heat transfer processes in various engineering applications by leveraging the enhanced thermal properties of nanofluids and considering factors such as wedge angle and velocity slip

Entropy minimization study of Maxwell nanofluid flow using oxides nanoparticles under transpiration and magnetic dissipation effects

Entropy generation is a measure of the irreversibility and inefficiency in a thermodynamic process. Minimizing entropy generation is desirable as it indicates a more efficient and optimized system. The present study focuses on flow dynamics and entropy minimization analysis in the MHD Maxwell nanofluid flow over the elastic surface with transpiration effects at the surface boundary. Furthermore, effects of important quantities such as magnetic field, electrical conductivity, joule heating, viscous dissipation, and heat source/sink are also considered. Two different types of nanofluids copper oxide-water and iron oxide-water are used, whereas the volume fraction of both nanofluids and base fluid are same. Similarity solutions are achieved by using similarity variables to transform the governing PDE’s systems into dimensionless ODE’s systems. The MATLAB algorithm bvp4c is used to perform numerical computations of nonlinear systems. Significant results of different parameters, such as volume fraction of nanoparticles, Eckert number, and magnetic parameter on entropy analysis, Bejan number, and velocity/temperature are comprehensively presented and discussed through graphs. It is realized that entropy minimization is possible for smaller values of nanoparticles volume fraction and Eckert number. The current analysis and data has significant uses in reducing energy losses in petroleum and chemical engineering systems such as production enhancement, thermal energy storage, energy efficient cooling systems.

Analytical analysis of graphene oxide ethylene glycol and graphene oxide blood base nanofluid over a vertical surface

This work considers the analytical analysis of graphene oxide ethylene glycol and graphene oxide blood base nanofluid over a vertical sheet. The principal objective of this study is to make an effort to improve the heat transfer ratio, which is the core part of the engineering and industrial sectors. Following a continuity check, the problem is modeled using the conservation rules of momentum and energy. Nonlinear PDEs are produced through modeling, which are then transformed into ODEs using the similarity transformation and thermophysical characteristics. The resultant ODEs are resolved using the Homotopy Asymptotic Method, and graphical interpretations are given to highlight the influence of different contributing parameters such as unsteady parameter, nanoparticle volume fraction, mixed convection parameter, Grashof number and Prandtl number on the velocity profile and temperature distribution. It is noted that increasing the values of nanoparticle volume fraction and stretching parameter slow down the velocity profile. Also, increasing the values of mixed convection parameter and Grashof number (Gr) enhance the velocity profile, and increasing values of Prandtl number and Graship number reduce the temperature distribution. The Nusselt number and the skin friction are examined through graphical representation. It is noted that increasing the value of mixed convection parameter decreases the skin friction of the fluids, and the Nusselt number decreases with the growing value of Prandtl number.

Natural convective MHD nanofluid flow past a vertical plate embedded in a porous medium with thermal diffusion and hall current

AbstractIn the present study, we explore MHD water‐based nanofluid flow past an impulsively started infinite vertical plate embedded in a porous medium, including ramped velocity and concentration in the presence of Hall effect, thermal radiation, chemical reaction, heat source/sink and thermal diffusion. The set of non‐dimensional governing equations is computed utilising the Laplace transform method. The effect of different embedded parameters on velocity, temperature and concentration profiles have been plotted and graphically deliberated through physical interpretation. Variations of the Nusselt number, Sherwood number and skin friction are also studied. It is established that for higher values of nanoparticle volume fraction, the primary and secondary velocities and concentration of the fluid reduce. The temperature enhances by increasing the nanoparticle volume fraction. The thermal diffusion upsurges the fluid concentration. The rate of momentum transfer falls as Hall current parameter increases.

Statistical modeling for Ree-Eyring nanofluid flow in a conical gap between porous rotating surfaces with entropy generation and Hall Effect

The attention of the current study is on the flow of a non-Newtonian incompressible Cu-Water nanofluid flow. The water is assumed as base fluid, while copper is used as nanoparticles. The Ree-Eyring prototype describes the performance of non-Newtonian nanofluids. There is a conical gap that nanofluid flow fills among the plane disc and the cone's stationary/rotational porous faces. Additionally taken into account are heat, mass transfer, and entropy production. The given mathematical model is unique due to the effects of a vertically applied Hall Effect, Ohmic dissipation, viscous dissipation, and chemical processes. The Ree-Eyring fluid constitutive equations, as well as the cylindrical coordinates, have been interpreted. The model equations for motion, heat, and concentration can be changed in the collection of non-linear ODEs by employing the applicable similarity transform. This method allocates a couple of nonlinear ODEs relating to velocity, temperature, and concentration distributions. The shooting scheme (bvp4c technique) is used to solve these equations numerically. Statistical analysis like probable error, correlation, and regression are exploited. The probable error is estimated to compute the consistency of the calculated correlation features. The theoretical data is analyzed in both graphical and tabular forms. The modeled parameters like, magnetic number, porosity parameter, Eckert number, chemical reaction parameter, Brownian motion parameter, thermophoretic parameter, Schmidt number, Hall recent parameter, radiation parameter, and volume fraction are discussed in details graphically and theoretically. The outcomes indicate that the velocity components are greater for greater values of nanoparticle volume fraction and Weissenberg number, whereas for enormous values of magnetic and porosity parameters, the velocity components fall.

Comparative heat transfer analysis of electroconductive Fe3O4–MWCNT– water and Fe3O4–MWCNT– kerosene hybrid nanofluids in a square porous cavity using the non-Fourier heat flux model

The analysis of heat transmission and fluid flow characteristics within the cavity is useful to improve the features of several applications including energy storage devices and hybrid fuel cells. With this motivation, the present model investigates the characteristics of magneto-convective heat transmission and fluid flow within a square porous enclosure with hot and cold slits. The heat transfer features of electrically conducting hybrid nanofluids Fe3O4–MWCNT– water and Fe3O4–MWCNT– kerosene are analyzed inside the enclosure. The non-Fourier thermal flux model is deployed, and the internal heat absorption/generation effect is considered. The marker-and-cell numerical scheme is adopted to solve the transformed dimensionless mathematical model with associated initial–boundary conditions. An exhaustive parametric investigation is implemented to estimate the influence of key parameters on transport phenomena. The computations show that augmenting the Hartmann number values modifies the fluid flow and temperature features substantially for both hybrid nanofluids. Enhancing the values of nanoparticles volume fraction promotes the heat transfer. When 5% Fe3O4–MWCNT nanoparticles are suspended into water and kerosene base fluids, Fe3O4–MWCNT– kerosene hybrid nanofluid achieves 6.85% higher mean heat transfer rate compared to Fe3O4–MWCNT– water hybrid nanoliquid. In the existence of heat absorption, the mean rate of heat transfer of Fe3O4–MWCNT– water hybrid nanofluid is 78.92% lower than Fe3O4–MWCNT– kerosene hybrid nanoliquid. Greater energy transmission is noticed in the case of Fe3O4–MWCNT– kerosene hybrid nanofluid, and the enhanced fluid flow is noticed in the case of Fe3O4–MWCNT– water hybrid nanofluid. Fourier's model (δe=0) estimates higher heat transfer rate than that of the Cattaneo–Christov (non-Fourier) heat flux model (δe≠0).

Mixed convection flow of Cu-water nanofluid having differently shaped nanoparticles past a moving wedge

Steady boundary layer mixed convection flow over a wedge moving parallel to a free stream in nanofluid having differently shaped nanoparticles is numerically investigated. The aspire of this article is to examine the combined influences of mixed convection, suction/blowing and variable shape of nanoparticles on motion of nanoliquid past a moving wedge moving faster/slower than the free stream. Nanofluid flow past a moving wedge is commendable of extraordinary concentration owing to its escalating applications in industrialized processes and technologies and so, the significance of this study is that the model is pertinent to a variety of manufacturing sectors for submissive control of nanoelements. The overriding equations under boundary layer approximations along with the matching conditions at the boundary are transformed to ordinary differential equations with the help of similarity alterations. Shooting technique is adapted to solve these equations numerically via Runge Kutta method using MATHEMATICA. Outcomes of the present study for a number of meticulous cases are assessed with the existing outcomes in open text and found a very well conventionality. The effects of various crucial parameters on velocity and temperature profiles of the fluid are accessible and analyzed graphically. The velocity of Cu-water nanofluid increases with the enhanced strengths of suction parameter, wedge angle parameter and also with the enhanced values of nanoparticle volume fraction. In comparison to spherical shaped nanoparticles, elevated temperature is experienced for nanoparticles of non-spherical shape. Also, the skin friction coefficient and surface heat transfer rates for some of the parameters are explored numerically. The outcomes of this learning depict numerous inspiring features that merit supplementary learning of the problem.

Galerkin finite element analysis for buoyancy driven copper-water nanofluid flow and heat transfer through fins enclosed inside a horizontal annulus: Applications to thermal engineering

The hydrothermal significance of natural convection flow through the horizontal annulus reveal most important implication and those geometrical shapes are introduced in enormous industrial and engineering implementations related to superheaters, heat exchangers, hydrogen fuel cells, gas turbines, solar collectors, vehicle engines, and turbomachinery etc. With this motivation, the current advance study enlightens the natural convection heat transfer impacts of Cu−water nanofluid flow through horizontal annulus with inserting Fins at the inner cylinder. Different fins numbers (0, 2 and 4) are inserted at inner cylinder wall are heated. The outer cylinder kept at cooled temperature. The significance nanoparticles fraction (Φ=1%−5%), Rayleigh number (1000,10000and100000) and different fin numbers (0,2and4) on fluid flow, thermal field, and local Nusselt number investigated. The Galerkin finite element method has been employed to carry out the numerical solution for different values of flow controlling parameters. The impacts of prominent parameter on streamlines, isotherms and 2d graphs are analyzed. The analysis concluded that velocity and thermal outcomes upsurges for Rayleigh number. It is conclude that important thermal transfer increment can be observed due to the occurrence of solid nanoparticles and that is boosted by growing the solid particle fraction. The velocity is reduced by increasing the values of nanoparticle volume fraction. Additionally larger heat transfer for nanoparticles Volume fraction Φ=5% as compare to Φ=1%.

Thermal enhancement and numerical solution of blood nanofluid flow through stenotic artery

The blood flow through stenotic artery is one of the important research area in computational fluid mechanics due to its application in biomedicine. Aim of this research work is to investigate the impact of nanoparticles on the characteristics of human blood flow in a stenosed blood artery. In under consideration problem Newtonian fluid is assumed as human blood. Newtonian fluid flows through large blood vessels (more than 300 μm). The constitutive equations together with the boundary conditions are diminished to non-dimensional form by using boundary layer approximation and similarity transfiguration to attain the solution of velocity and temperature distribution of blood flow through arterial stenosis numerically with the help of Matlab bvp4c. The results for physical quantities at cylindrical surface are calculated and their effects are also presented through tables. The heat transfer rate increases throughout the stenosed artery with the concentration of copper nanoparticle. Velocity curve decreases by increasing the values of flow parameter and nanoparticle volume fraction. Temperature curve increases due to increase in the values of nanoparticle volume fraction and decrease in Prandtl number.

Thermal characteristics of kerosene oil-based hybrid nanofluids (Ag-MnZnFe2O4): A comprehensive study

Hybrid nanofluids are new and most fascinating types of fluids that involve superior thermal characteristics. These fluids exhibit better heat-transfer performance as equated to conventional fluids. Our concern, in this paper, is to numerically interpret the kerosene oil-based hybrid nanofluids comprising dissimilar nanoparticles like silver (Ag) and manganese zinc ferrite (MnZnFe2O4). A numerical algorithm, which is mainly based on finite difference discretization, is developed to find the numerical solution of the problem. A numerical comparison appraises the efficiency of this algorithm. The effects of physical parameters are examined via the graphical representations in either case of nanofluids (pure or hybrid). The results designate that the porosity of the medium causes a resistance in the fluid flow. The enlarging values of nanoparticle volume fraction of silver sufficiently increase the temperature as well as velocity. It is examined here that mixture of hybrid nanoparticles (Ag-MnZnFe2O4) together with kerosene oil can provide assistance in heating up the thermal systems.

Analysis of energy and momentum transport for Casson nanofluid in a microchannel with radiation and chemical reaction effects

ABSTRACT The study of Casson nanofluid plays a prominent role in biomedicine, magnetic resonance imaging and thermal enhancement of energy system due to the eminence of its thermophysical properties. By considering various practical applications, in this article the steady, laminar, electromagnetohydrodynamic flow of Casson nanofluid across parallel plates with the effect of Hall current, chemical reaction, modified Darcy's law and Joule heating have been taken into consideration. Gold and Silver nanoparticles of sphere shape are considered in blood taken as conventional base fluid with volume fraction of 1%. However, for comparison, other shapes of nanoparticles are also considered. The system of dimensional governing equations of nanofluid are converted to dimensionless set of equations using pertinent non-dimensional quantities. The analytical solutions are presented for the system of equations. The obtained exact solution for nanofluid velocity, nanofluid temperature, nanofluid concentration, Sherwood number, Nusselt number and shear stress are displayed graphically to see the effectiveness of sundry parameters. It is found that the velocity and temperature decreases, while concentration of Ag-blood and Au-blood rises with increased values of nanoparticle volume fraction. Performance of nanoparticle of sphere shape is lowest and lamina shape is highest in terms of heat and mass transfer. The present study may be useful in further studies of tumour therapy, biomedical imaging and cancer therapy.

Influence of various shapes of nanoparticles on unsteady stagnation-point flow of Cu-H2O nanofluid on a flat surface in a porous medium: A stability analysis

The nanofluid and porous medium together are able to fulfill the requirement of high cooling rate in many engineering problems. So, here the impact of various shapes of nanoparticles on unsteady stagnation-point flow of Cu–H2O nanofluid on a flat surface in a porous medium is examined. Moreover, the thermal radiation and viscous dissipation effects are considered. The problem governing partial differential equations are converted into self-similar coupled ordinary differential equations and those are numerically solved by the shooting method. The computed results can reveal many vital findings of practical importance. Firstly, dual solutions exist for decelerating unsteady flow and for accelerating unsteady and steady flows, the solution is unique. The presence of nanoparticles affects the existence of dual solution in decelerating unsteady flow only when the medium of the flow is a porous medium. But different shapes of nanoparticles are not disturbing the dual solution existence range, though it has a considerable impact on thermal conductivity of the mixture. Different shapes of nanoparticles act differently to enhance the heat transfer characteristics of the base fluid, i.e., the water here. On the other hand, the existence range of dual solutions becomes wider for a larger permeability parameter related to the porous medium. Regarding the cooling rate of the heated surface, it rises with the permeability parameter, shape factor (related to various shapes of Cu-nanoparticles), and radiation parameter. The surface drag force becomes stronger with the permeability parameter. Also, with growing values of nanoparticle volume fraction, the boundary layer thickness (BLT) increases and the thermal BLT becomes thicker with larger values of shape factor. For decelerating unsteady flow, the nanofluid velocity rises with permeability parameter in the case of upper branch solution and an opposite trend for the lower branch is witnessed. The thermal BLT is thicker with radiation parameter. Due to the existence of dual solutions, a linear stability analysis is made and it is concluded that the upper branch and unique solutions are stable solutions.

Analysis of Platelet Shape Al2O3 and TiO2 on Heat Generative Hydromagnetic Nanofluids for the Base Fluid C2H6O2 in a Vertical Channel of Porous Medium

An analytical investigation is performed on the unsteady hydromagnetic flow of nanoparticles Al2O3 and TiO2 in the EG base fluid through a saturated porous medium bounded by two vertical surfaces with heat generation and no-slip boundary conditions. The physics of initial and boundary conditions is designated with the flow model's non-linear partial differential equations. The analytical expressions of nanofluid velocity and temperature with the channel are derived, and Matlab Codes are used to plot the significant results for physical variables. From the physical point of view for nanofluid velocity and temperature results, the base fluid C2H6O2 has a higher viscosity and thermal conductivity than that of water. Physically, the platelet shape Al2O3 nanofluid has the highest velocity than TiO2 nanofluid. It is found that the velocity of nanofluid enhanced the porosity and nanoparticles volume fraction for Al2O3 - EG and TiO2 - EG base nanofluids. However, this trend is reversed for the effects of heat generation. Obtained results indicate that an increase in nanoparticles volume fraction raises the skin friction near the surface, but profiles gradually become linear, due to less frictional effects of nanoparticles. Moreover, due to higher values of nanoparticles volume fraction, the thermal conductivity is raised, and thus the thickness of the thermal boundary layer is declined. The results show that the method provides excellent approximations to the analytical solution of nonlinear system with high accuracy. Metal oxide nanoparticles have wide applications in various fields due to their small sizes, such as the pharmaceutical industry and biomedical engineering. HIGHLIGHTS Impact of platelet shape Al2O3 and TiO2 for base fluid C2H6O2 is studied In Couette and Poiseuille flow, nanoparticles play a vital role to enhance the heat transfer The infinite series solution has been used for solving the non-linear PDE’s The uses of Al2O3 and TiO2 in significant heat transfer applications is overviewed The physiochemical and structural features of metal oxide nanoparticles have diverse biomedical applications GRAPHICAL ABSTRACT

Study of the MHD Flow of Casson Nanofluid in the Presence of Oxides Nanoparticles Based C2H6O2/H2O Under Constant Heat Flux Boundary Condition

In this study, a numerical investigation of free convection in magneto-hydrodynamic (MHD) Casson nanofluid flow with heat transfer over a stretching sheet and with constant heat flux boundary condition is done. A magnetic field is considered normal to the stretching sheet. Two types of nanoparticles with various conductivities, such as iron oxide and graphene oxide are suspended in ethylene glycol/water-based Casson nanofluid. An implicit finite difference scheme known as Keller-box method has been employed in order to solve the set of nonlinear partial differential equations resulted from the governing equations, namely continuity, momentum, and energy equations. The effects of the MHD Casson nanofluids parameters on the physical properties such that local skin friction coefficient, local Nusselt number, velocity, and temperature have been displayed and discussed. The study has revealed that ethylene glycol has higher velocity and less temperature than water with different values of nanoparticle volume fraction, magnetic, and Casson parameters with the existence of Fe3O4/GO nanoparticles. Comparisons with previous studies show that the proposed method is in good agreement with other results.

Effects of Second-Order Slip Flow and Variable Viscosity on Natural Convection Flow of CNTs − Fe 3 O 4 /Water Hybrid Nanofluids due to Stretching Surface

This study deals with natural convection unsteady flow of CNTs − Fe 3 O 4 /water hybrid nanofluids due to stretching surface embedded in a porous medium. Both hybrid nanoparticles of SWCNTs − Fe 3 O 4 and MWCNTs − Fe 3 O 4 are used with water as base fluid. Effects of hybrid nanoparticles volume friction, second-order velocity slip condition, and temperature-dependent viscosity are investigated. The governing problem of flow is solved numerically employing spectral quasilinearization method (SQLM). The results are presented and discussed via embedded parameters using graphs and tables. The results disclose that the thermal conductivity of CNTs − Fe 3 O 4 / H 2 O hybrid nanofluids is higher than that of CNTs − H 2 O nanofluids with higher value of hybrid nanoparticle volume fraction. Also, the results show that momentum boundary layer reduces while the thermal boundary layer gros with higher values of temperature-dependent viscosity and second-order velocity slip parameters. The skin friction coefficient improves, and the local heat transfer rate decreases with higher values of nanoparticle volume fraction, temperature-dependent viscosity, and second-order velocity slip parameters. Furthermore, more skin friction coefficients and lower local heat transfer rate are reported in the CNTs − Fe 3 O 4 / H 2 O hybrid nanofluid than in the CNTs − H 2 O nanofluid. Thus, the obtained results are promising for the application of hybrid nanofluids in the nanotechnology and biomedicine sectors.

MIXED CONVECTION IN A SINGLE-WALLED CARBON NANOTUBE-WATER NANOFLUID FILLED PARTIALLY HEATED TRIANGULAR LID-DRIVEN CAVITY HAVING AN ELASTIC BOTTOM WALL

In this study, mixed convection of nanofluid filled triangular cavity with a partial heater and having an elastic bottom wall is analyzed with finite element method. Left vertical wall is partially heated while the inclined wall is kept at constant lower temperature. The bottom wall is flexible and inclined wall is moving at constant speed. Influences of Richardson number, elastic modulus of flexible wall, solid nanoparticle volume fraction on the convective heat transfer characteristics are analyzed. It was observed that, lower values of Richardson number, elastic modulus of the flexible wall and higher values of nano-particle volume fraction resulted in higher local and average heat transfer enhancements. Average heat transfer enhanced significantly when solid particle volume fraction of nanoparticle was increased. Enhancements up to 121% were obtained at solid volume fraction of 0.04 as compared to pure water at Richardson number of 1. Effects of elastic modulus of the bottom wall were found to be marginal and at Ri=1, enhancements up to 2% were achieved by using a more flexible wall.

Lower Stagnation Point Flow of Convectively Heated Horizontal Circular Cylinder in Jeffrey Nanofluid with Suction/Injection

Lower stagnation point flow of Jeffrey nanofluid from a horizontal circular cylinder is addressed under the influences of suction/injection, mixed convection and convective boundary conditions. Copper (Cu) is taken as the nanoparticles while Carboxymethyl cellulose (CMC) water is taken as the base fluid. The transformed boundary layer equations through the non-dimensional variables and non-similarity transformation variables are subsequently tackled by means of the Runge-Kutta Fehlberg method (RKF 45). The impact of dimensionless parameters such as the suction/injection, nanoparticles volume fraction and Deborah number are graphically presented and discussed in detail. The outcomes reveal that the velocity and temperature profiles are both augmented with rising values of nanoparticles volume fraction. Velocity profile escalates as suction/injection parameter rises but declines as Deborah number upsurges. Temperature profile reduces when suction/injection parameter enlarges and augments when Deborah number increases.