non-Newtonian Nanofluid Flow Research Articles

Buoyancy-Aided Mixed Convection Between Shear-Thinning Non-Newtonian Nanofluids and Unbounded Elliptic Cylinders in a Vertical Channel

This work presents buoyancy-driven mixed convective flow and heat transfer phenomena of an isothermally heated horizontal elliptic cylinder in vertically upward unbounded flow of power-law type non-Newtonian nanofluids using ANSYS Fluent. The governing continuity, momentum and energy equations for the shear-thinning power-law nanofluids along with suitable boundary conditions are simultaneously solved within the limitations of Boussinesq approximation. The semi implicit method for pressure-linked equations algorithm along with the quadratic upstream interpolation for convective kinematics scheme for discretizing the convective terms in both momentum and energy equations are adopted. The ranges of parameters considered for this study are: volume fraction of nanoparticles, 0.005–0.045; aspect ratio of elliptic cylinder, 0.5–2.5; and Richardson number, 0–40; and a representative Reynolds number of 20. The streamline patterns, surface pressure coefficient distributions, total drag coefficients, isotherm contours, and Nusselt numbers are presented for better understanding of heat transfer and flow phenomena around elliptic cylinders. Briefly results indicate that the total drag coefficient is found to increase with the increasing Richardson number whereas it decreases with the increasing volume fraction of nanoparticles. The average Nusselt numbers are found to increase with increasing Richardson number and increasing volume fraction of nanoparticles.

Rayleigh-Bénard convection of non-Newtonian nanofluids considering Brownian motion and thermophoresis

In this study, the flow and heat transfer of non-Newtonian Al2O3-water nanofluid in Rayleigh-Bénard cavity are numerically studied. Power-law model is used to describe the non-Newtonian effect of nanofluids in which the flow behavior index depends on the nanoparticle volume fraction. We present a systematic study of the Al2O3-water nanofluid for Rayleigh number of 1000 ≤ Ra ≤ 500000, cavity aspect ratio of 0.25 ≤ AR ≤ 4.0 and nanoparticle volume fraction of 0% ≤ϕ≤ 3%. The flow pattern inside the cavity changes complicatedly as Ra increases and the heat transfer performance of the system is strongly affected by the flow pattern. The convectional structure is influenced by both of the shear-thinning effect and the variation of effective viscosity. The average Nusselt number changes non-monotonically because of the flow pattern change under the variation of Ra and n. The consideration of Brownian motion and thermophoresis could bring about 3% increase of average Nusselt number, and the value varies slightly with different AR and ϕ. The comparison between non-Newtonian and Newtonian models shows that noticeable underestimation of heat transfer performance could be resulted by Newtonian model. The average Nusselt number of non-Newtonian model is approximately 1.5 times to that of Newtonian model, and the deviation is more pronounced with the increase of particle volume fraction.

Boundary layer flow of radioactive non-Newtonian nanofluid embedded in a porous medium over a stretched sheet using the spectral relaxation method

Abstract The main objective of this study is to analyze the steady, two dimensional flow of non-Newtonian nanofluid through a porous medium over a stretched sheet. By means of the comparison of other Non-Newtonian liquids Eyring-Powell fluid model have some more advantages because they act as viscous liquids at high shear rates as well. A uniform external magnetic field is applied on the present model. The heat and mass transfer rates are studied in the present study moreover considered non-Newtonian fluid is abiding the Eyring-Powell model. In the energy equation radiation effect is also considered. The problem is mathematically formulated from the flow and there after solved numerically with the help of spectral relaxation method (SRM) along with the mat lab package. There is a significant improvement in the convergence of proposed technique in conjunction with spectral over relaxation (SOR) method. It very well may be noticed that number of iterations are diminished combination with the SOR strategy. Effects of physical parameters of the problem such as, permeability, magnetic in addition to the fluid material parameters like Eckert number, radiation parameter, Prandtl number and Lewis number are analyzed through graphs and tables with some notable applications. The outcomes show that the velocity of the fluid is higher for non-Newtonian nanofluid than the classical nanofluid. An increase in the viscous dissipation and radiation causes increase in the fluid temperature.

An Unsteady Pulsatile Flow of Some MHD Non-Newtonian Nanofluids with Hall Current and Ion Slip Through a Porous Medium

An Unsteady Pulsatile Flow of Some MHD Non-Newtonian Nanofluids with Hall Current and Ion Slip Through a Porous Medium

MHD Boundary Layer Flow of Non-Newtonian Power-Law Nanofluid with Thermal Radiation

MHD Boundary Layer Flow of Non-Newtonian Power-Law Nanofluid with Thermal Radiation

Entropy Analysis of 3D Non-Newtonian MHD Nanofluid Flow with Nonlinear Thermal Radiation Past over Exponential Stretched Surface.

The present study characterizes the flow of three-dimensional viscoelastic magnetohydrodynamic (MHD) nanofluids flow with entropy generation analysis past an exponentially permeable stretched surface with simultaneous impacts of chemical reaction and heat generation/absorption. The analysis was conducted with additional effects nonlinear thermal radiation and convective heat and mass boundary conditions. Apposite transformations were considered to transform the presented mathematical model to a system of differential equations. Analytical solutions of the proposed model were developed via a well-known homotopy analysis scheme. The numerically calculated values of the dimensionless drag coefficient, local Nusselt number, and mass transfer Nusselt number are presented, with physical insights. The graphs depicting the consequences of numerous parameters on involved distributions with requisite deliberations were also a part of this model. It is seen that the Bejan number is an increasing function of the thermal radiation parameter.

Slip velocity and temperature jump of a non-Newtonian nanofluid, aqueous solution of carboxy-methyl cellulose/aluminum oxide nanoparticles, through a microtube

PurposeWith respect to two new subjects, i.e. nanofluids and microchannels, in heat transfer systems and modern techniques used for building them, this paper aims to study on effect of using aluminum oxide nanoparticles in non-Newtonian fluid of aqueous solution of carboxy-methyl cellulose in microtube and through application of different slip coefficients to achieve various qualities on surface of microtube.Design/methodology/approachSimultaneously, the effect of presence of nanoparticles and phenomenon of slip and temperature jump has been explored in non-Newtonian nanofluid in this essay. The assumption of homogeneity of nanofluid and fixed temperature of wall in microtube has been used in modeling processes.FindingsThe results have been presented as diagrams of velocity, temperature and Nusselt Number and the investigations have indicated that addition of nanoparticles to the base fluid and increase in microtube slip coefficient might improve rate of heat transfer in microtube.Originality/valueThe flow of non-Newtonian nanofluid of aqueous solution of carboxy methyl cellulose-aluminum oxide has been determined in a microtube for the first time.

Entropy Generation Analysis of MHD Slip Flow of Non-Newtonian Cu-Casson Nanofluid in a Porous Microchannel Filled with Saturated Porous Medium Considering Thermal Radiation

Entropy Generation Analysis of MHD Slip Flow of Non-Newtonian Cu-Casson Nanofluid in a Porous Microchannel Filled with Saturated Porous Medium Considering Thermal Radiation

Numerical analysis of mixed convection of two-phase non-Newtonian nanofluid flow inside a partially porous square enclosure with a rotating cylinder

In this study, mixed convection heat transfer of the non-Newtonian power-law nanofluid including CuO nanoparticles, inside a partially porous square enclosure with a concentric rotating cylinder and a hot side wall is numerically investigated. Two-phase mixture model is utilized for nanofluid flow simulation and the mixture viscosity and thermal conductivity are computed by Corcione’s correlation. The effect of different angular velocity (− 4000 ≤ Ω ≤ 4000) for various Rayleigh (104 ≤ Ra ≤ 106), Darcy (10−4 ≤ Da ≤ 10−1), power-law index (0.8 ≤ n ≥ 1.2) and effective to base fluid thermal conductivity ratio (keff/kf= 16, 4) are studied on heat transfer. Results are presented and compared in terms of the average Nusselt number, and streamline and isotherm contours. Outcomes show that for different kinds of fluid, depending on the value of Ra, Da, keff/kf and the amount and direction of angular velocity, heat transfer can be improved by augmenting heat convection and also can be deteriorated by increasing viscosity. Consequently, optimal values of Ra, Da, keff/kf and Ω exist in order to maximize the average Nu number.

EMHD time-dependant tangent hyperbolic nanofluid flow by a convective heated Riga plate with chemical reaction

The present exploration addresses the boundary layer electro-magnetohydrodynamic (EMHD) flow of time-dependant non-Newtonian tangent hyperbolic nanofluid that is electrically conducting past a Riga surface with variable thickness and slip boundary condition. Configuration flow modeling is deduced considering chemical reaction and heat generation/absorption with the impacts of Brownian motion and thermophoresis. Also a newly proposed boundary condition with zero mass flux has been presented in the current contribution. Numerical solution of the governing non-linear differential equations is presented by considering the shooting technique. Graphical illustrations pointing out the aspects of distinct physical parameters on the non-Newtonian nanofluid velocity, temperature and concentration fields are introduced. From the computational results, the concentration distribution gives a decreasing function of the chemical reaction and Brownian motion parameters. Higher values of shape parameter yield a negative influence on the mechanical properties of the surface. The Hartmann number leads to maximize both of velocity field and skin friction coefficient. Additionally, numerical computed values of the skin friction, local Nusselt and Sherwood numbers are depicted with the needful discussion.

Unsteady MHD boundary layer flow of tangent hyperbolic two-phase nanofluid of moving stretched porous wedge

PurposeThe purpose of this paper is to address the thermo-physical impacts of unsteady magneto-hydrodynamic (MHD) boundary layer flow of non-Newtonian tangent hyperbolic nanofluid past a moving stretching wedge. To delineate the nanofluid, the boundary conditions for normal fluxes of the nanoparticle volume fraction are chosen to be vanish.Design/methodology/approachThe local similarity transformation is implemented to reformulate the governing PDEs into coupled non-linear ODEs of higher order. Then, numerical solution is obtained for the simplified governing equations with the aid of finite difference technique.FindingsNumerical calculations point out that pressure gradient parameter leads to improve all skin friction coefficient, rate of heat transfer and absolute value of rate of nanoparticle concentration. As well as, lager values of Weissenberg number tend to upgrade the skin friction coefficient, while power law index and velocity ratio parameter reduce the skin friction coefficient. Again, the horizontal velocity component enhances with upgrading power law index, unsteadiness parameter, velocity ratio parameter and Darcy number and it reduces with rising values of Weissenberg number.Originality/valueA numerical treatment of unsteady MHD boundary layer flow of tangent hyperbolic nanofluid past a moving stretched wedge is obtained. The problem is original.

Heat and Mass Transfer of Non-Newtonian Nanofluid Flow Over a Stretching Sheet with Non-Uniform Heat Source and Variable Viscosity

Heat and Mass Transfer of Non-Newtonian Nanofluid Flow Over a Stretching Sheet with Non-Uniform Heat Source and Variable Viscosity

Thermal Radiation and Heat Source Effects on MHD Non-Newtonian Nanofluid Flow Over a Stretching Sheet

Thermal Radiation and Heat Source Effects on MHD Non-Newtonian Nanofluid Flow Over a Stretching Sheet

Three-Dimensional Flow, Heat and Mass Transfer of MHD Non-Newtonian Nanofluid Due to Stretching Sheet

Three-Dimensional Flow, Heat and Mass Transfer of MHD Non-Newtonian Nanofluid Due to Stretching Sheet

Experimental investigation of forced convection heat transfer and friction factor of a non-Newtonian nanofluid flow through an annulus in the presence of magnetic field

In this current work, the forced convection heat transfer and pressure drop of a non-Newtonian nanofluid flow through an annulus are studied experimentally. The steady-state laminar flow of the nanofluid takes place in the presence of a constant heat flux and a constant magnetic field. The non-Newtonian nanofluid used is carboxymethyl cellulose (CMC)/copper oxide solution with 0.2% CMC weight fraction and 0.25, 0.5 and 1% volume fractions of copper oxide nanoparticles in the distilled water. Based on the experimental results obtained, the heat transfer coefficient augmented as the volume fraction of the nanoparticles was increased. Also, it was found that the presence of the magnetic field enhanced the heat transfer effectively. Based on the results, the mean Nusselt number for 1 vol% was increased by 16.49% compared to that of the base fluid.

Numerical Simulations on Magnetohydrodynamic Non-Newtonian Nanofluid Flow Over a Semi-Infinite Vertical Surface with Slipeffects

Numerical Simulations on Magnetohydrodynamic Non-Newtonian Nanofluid Flow Over a Semi-Infinite Vertical Surface with Slipeffects

An analytical study of the periodic laminar forced convection of non-Newtonian nanofluid flow inside an elliptical duct

In this study, an analytical solution was obtained for a laminar forced convection of non-Newtonian nanofluid flowing inside an elliptical duct, with inlet temperature varying periodically with the time. The solution was obtained using the Generalized Integral Transform Technique (GITT). The thermal behavior of Cu-water non-Newtonian nanofluid, described by the power-law model was investigated. Also, an accurate correlation was established to estimate the thermal length required to achieve 99% of the amplitude attenuation. The results show a significant effect of aspect ratio β/α and fluid behavior index on the temperature amplitude reduction. For instance, an elliptical duct with β/α = 0.25 reduces the thermal length Lth more than 50% compared with circular duct. Adding nanoparticles until 5% increases the heat transfer coefficient up to 27% for the cylindrical tube. Besides, the heat transfer coefficient is improved over 42% relatively to the cylindrical configuration by reducing the aspect ratio to 0.25. Therefore, adding 5% of nanoparticles both using an elliptical duct with β/α = 0.25, improves the mean heat transfer coefficient around 83% compared to the flow of water base fluid inside a cylindrical duct.

Heat transfer and fluid flow of pseudo-plastic nanofluid over a moving permeable plate with viscous dissipation and heat absorption/generation

The purpose of the present study is investigating the heat transfer of non-Newtonian pseudo-plastic nanofluid flow on a moving permeable flat plate with viscous dissipation and heat absorption/generation. The flow is uniform and parallel to the moving flat plate, and both flat plate and flow are moving on the same directions. The investigated parameters in this study are power-law index, permeability parameter, Eckert number, volume fraction of nanoparticles, nanoparticles type, velocity ratio and heat absorption/generation parameter. The nanoparticles used in this paper are Al2O3, TiO2, Cu and CuO dispersed in sodium carboxymethyl cellulose/water as the base fluid. By using suitable transformations, the governing partial differential equations are converted into the ordinary differential equations, and after that, the resulting ODEs are solved with Runge–Kutta-Fehlberg fourth–fifth-order numerical method. The results of this investigation showed that heat transfer of Newtonian and non-Newtonian nanofluids in the presence of viscous dissipation and generation/absorption of heat has an interesting behavior: For Newtonian fluid, by increasing the amounts of high-conductive nanoparticles to carrying fluid, a higher heat transfer is not obtained. For instance, copper nanoparticles, despite having highest thermal conductivity compared to other nanoparticles, show the lowest local Nusselt number. However, for pseudo-plastic non-Newtonian nanofluids the observed trend was reversed. Furthermore, in both Newtonian and non-Newtonian nanofluids, the local Nusselt number decreased, by increasing injection parameter, heat generation or volume fraction of nanoparticles (in high Eckert numbers). That is while, by enhancing the heat absorption, velocity ratio, suction parameter or volume fraction of nanoparticles (in low Eckert number), the local Nusselt number augments.

Convective stagnation point flow of a MHD non-Newtonian nanofluid towards a stretching plate

A numerical study is carried out for the magnetohydrodynamics (MHD) convective stagnation point flow of a incompressible nanofluid towards a stretching surface. The effects of Brownian motion and thermophoresis are incorporated for the characteristic of the nanofluid. The transformed dimensionless governing equations are solved directly by the collocation spectral method (CSM). Graphical results are presented and analyzed for non-dimensional velocities, temperature and nanoparticle concentration. The effects of Prandtl number, magnetic field, viscous dissipation, heat source/sink with suction/injection, Lewis number, thermophoresis parameters and Brownian motion parameter, etc., on flow, thermal and concentration boundary layer as well as on skin-friction coefficient, local Nusselt number and Sherwood number are obtained and discussed. The two-dimensional irregular characteristics have been found in the velocity and temperature distributions in the flow and normal directions.

Analysis of natural convective flow of non-Newtonian fluid under the effects of nanoparticles of different materials

The purpose of this paper is to examine the effects of natural convection flow of viscoelastic polydimethylsiloxane non-Newtonian nanofluid under the impact of nanoparticles of different materials past a vertical cone. The implications for operating parameters have been investigated using tables and it is noticed that the nanoparticles unveil substantial impact on the thermal conductivity of base fluid. The temperature profile and the rate of heat transfer behave as an increasing function of nanoparticles. It is found that tiny size particles are more efficacious as compared to large particles on the rate of heat transfer and fluid motion. To validate the current methodology, a numerical comparison is posed with previously published data.