Newtonian Nanofluid Research Articles

Stability analysis of mixed convection in a porous horizontal channel filled with a Newtonian Al2O3/Water nanofluid in presence of magnetic field and thermal radiation

• Stability analysis of mixed convection of Newtonian nanofluid in porous media. • Magnetic field and thermal radiation are taken into consideration in the problem. • Prandtl, and Richardson numbers maintain instabilities in convective flow . • Magnetic field, thermal radiation and medium's permeability stabilize the flow. • Nanoparticles into the base fluid increases the inertia of the fluid. This paper investigates a stability analysis of mixed convection of A l 2 O 3 / W a t e r nanofluid in a horizontal porous channel heated from below and cooled from above. Certain effects such as magnetic field and thermal radiation are taken into consideration. The permeability of the porous medium is described by Darcy's model. Starting from the Navier-Stokes equations to which the energy and Maxwell equations are coupled and under the assumption of an analysis in normal mode, a system of differential equations with eigenvalues governing the stability of the flow is derived and solved numerically by the spectral collocation method. The effects of the magnetic field, thermal radiation, volume fraction of nanoparticles, permeability of the medium and many other important parameters are presented and analyzed. The results show that the introduction of the nanoparticles into the base fluid increases the inertia of the fluid, which dampens the disturbances. Among the different geometric shapes of nanoparticles, the blade shape has a more stabilizing effect on the stability of the convective flow. It is also shown that oxide-type nanoparticles have a more stabilizing effect compared to metallic-type nanoparticles on small wave number disturbances. In the case of large wave numbers, the opposite is observed. Parameters such as Prandtl number and Richardson number maintain instabilities in convective flow. On the other hand, the magnetic field, the thermal radiation and the permeability of the porous medium affect the stability of the convective flow and all have stabilizing effects, which makes it possible to control the mixed convection of nanofluid.

A numerical simulation of electrically conducting micro-channel nanofluid flow with thermal slip effects

This article is concerned with the mixed convective magnetohydrodynamics (MHD) Newtonian nanofluid flow through a porous vertical channel with radiation effects. Copper nanoparticles are considered in the base fluid. An induced magnetic field is retained for the conducting and non-conducting walls of the channel. Momentum and thermal slip boundary conditions are utilized on the channel walls. The heat generation effect is also taken into account for this model. The governing partial differential equations are converted into nonlinear ordinary differential equations using the similarity variables. Numerical results of the transformed nonlinear governing equations are obtained using the shooting method through MATLAB software. The parameters like pressure gradient, radiation parameter, magnetic parameter, Prandtl number, and Reynolds number play a vital role in the heat and fluid flow. It is observed that enhanced impact of pressure gradient declined the velocity profile which affects directly the center of the flow channel. It is also witnessed that the induced magnetism rises when the magnetic Prandtl number gets higher values.

Thermal cooling process by nanofluid flowing near stagnating point of expanding surface under induced magnetism force: A computational case study

This paper is dedicated to the exam of entropy age and research of the effect of mixing nanosolid additives over an extending sheet. In this review, Newtonian nanofluid version turned into researched at the actuated appealing field, heat radiation and variable heat conductivity results. With becoming modifications, the proven PDEs are moved into popular differential situations and paintings mathematically making use of a specific mathematical plan called the Keller box method (KBM). The ranges of different dimensionless parameters used in our study are volume fraction of nanoparticles 0.01 ≤ φ ≤ 0.04 , magnetic parameter 0.5 ≤ Λ ≤ 2 , thermal radiation 0.1 ≤ N r ≤ 0.3 , heat source/sink parameter 0.5 ≤ Q 0 ≤ 2 , Prandtl number 5.7 ≤ P r ≤ 6.2 , variable thermal conductivity 0.1 ≤ ε ≤ 0.3 , reciprocal magnetic Prandtl number 0.6 ≤ λ ∗ ≤ 1 , Brinkman number 5 ≤ B r ≤ 15 , Reynolds number 5 ≤ R e ≤ 15 , which shows up during mathematical arrangement are shown as tables and charts.Positive modifications in heat radiation and heat conductivity affects increment the hotness pass coefficient of solar primarily based totally plane wings. Titanium alloy primarily based totally water (H 2 O) are taken into consideration for our research. We will likewise alternate the grouping of nanoparticles to pay attention on their impact on numerous dynamic barriers of the framework. We can see that because the Reynolds range and Brinkman range increment, the entropy increments. The thermodynamic exhibition of Titanium alloy-water (Ti 6 Al 4 V–H 2 O) nanofluid has been portrayed higher that of base nanofluid with comparable situations. Recorded hypothetical reproductions may be greater beneficial to similarly increase daylight primarily based totally nuclear strength frameworks.

Temperature and Mass Dispersion of Free Convective Radiative Non - Newtonian Nano Fluid Flow between Two Parallel Plates

In the current study, impact of the thermal radiation along with thermophoretic diffusion and Brownian motion ramifications on the flow of non-Newtonian nanofluid represented by Couple stress fluid between horizontal parallel plates are discussed. Where the parallel plates are kept at various temperatures and concentrations, the fluid is periodically sucked and injected at the upper plate and lower plate respectively. The governing non-linear partial differential equations are reduced into a non-linear system of ordinary differential equations with the aid of similarity transformations. The resultant non-dimensional equations are subsequently solved by using shooting-method with the usual 4th order Runge-Kutta scheme. The non-dimensional velocity and temperature variations along with mass transfer profiles are analyzed for different fluid and parameters as well as geometric parameters and the same are plotted in the form of graphs. Skin- friction coefficient in non-dimensional along with heat & mass transfer rates are studied numerically. It is found that there is a direct relationship between temperature component of the fluid and the Brownian movement parameter, while the concentration component of the fluid is decreasing with respect to that of thermophoresis parameter. Further, mass transfer decreases with increasing couple stress fluid parameter.

Friction Factor and Heat Transfer of Giesekus-Fluid-Based Nanofluids in a Pipe Flow

The friction factor and heat transfer of Giesekus-fluid-based nanofluids in a pipe flow were studied in the ranges of 0.5 ≤ Reynolds number (Re) ≤ 500, 1 ≤ Weissenberg number (Wi) ≤ 8, 0.5% ≤ particle volume concentration (Φ) ≤ 3.0%, 0 ≤ viscosity ratio (β0) ≤ 1, and 0 ≤ mobility parameter (α) ≤ 0.5. Our numerical method was validated by comparing the results with available ones in the literature. The effects of Wi, Φ, β0, Re, and α on the relative friction factor (Cf/CfNew), Nusselt number (Nu), and ratio (PECnf/PECf) of energy performance evaluation criterion for Giesekus-fluid-based nanofluids to those for Giesekus fluid were discussed. The results showed that the values for the Cf/CfNew and Nu of Giesekus-fluid-based nanofluids were larger than those for Newtonian fluid-based nanofluids and those for pure Giesekus fluid. The values for Cf/CfNew increased with increasing Φ and Re, but they increased with decreasing β0 and α. As Wi increased, the values of Cf/CfNew first increased and then decreased. The values of Nu and PECnf/PECf were enhanced with increasing Wi, Φ, Re, and α, but with decreasing β0. It is more effective to use Giesekus-fluid-based nanofluids to improve heat transfer with the conditions of a larger Wi, Φ, Re, and α and a smaller β0. Finally, the correlation formula for PECnf/PECf as a function of Wi, Φ, β0, Re, and α was derived.

MHD Ellis nanofluids flow around rotating cone in the presence of motile oxytactic microorganisms

This paper presents novel treatments for the Ellis non-Newtonian nanofluids flow over a rotating cone in the presence of motile oxytactic microorganisms. These treatments are depending on solutions of the stress tensor equations at specific values of the power-law index α (α = 0,0.5,1,2) and introducing the stress as expressions in terms of the velocity gradients. Here, four systems of the governing equations for each value of α are presented and the non-similar forms for these systems are obtained. An efficient finite difference method based on the Blottner technique is applied to solve the converted systems. Various important impacts are examined in these simulations such as, magnetic field, non-linear radiation, viscous dissipation, heat generation and Joule heating. Wide ranges of the non-similar parameters are considered, namely, 0 ≤ ξ ≤ 10, 0 ≤ η ≤ 35. The major results revealed that, the skin friction gets higher values at the Ellis case α = 2 while the Newtonian nanofluids α = 1 gives the highest heat transfer rate. Both the velocity and temperature gradients are diminishing as the bioconvection Rayleigh number is enhanced.

Planar Couette flow of power law nanofluid with chemical reaction, nanoparticle injection and variable thermal conductivity

This article presents the transport of thermal energy and mass in the mixed convection steady planar Couette flow of power-law nanofluid with variable thermal conductivity through a permeable microchannel. The entropy production deliberation here is to investigate the irreversibility aspects. The momentum equation has been made by the permeability of the porous medium, Hall current effect, thermal, and solutal bouncy force. The mathematical model for the thermal energy has been formulated by Ohmic dissipation, Brownian motion, temperature-dependent thermal conductivity, and thermophoresis. The microchannel boundaries retain the no-slip boundary conditions. The concentration formulation has been made by nanoparticle injection rate and chemical reaction. The momentum, energy, and solutal formulations have been numerically cracked by means of Runge–Kutta–Fehlberg fourth fifth-order numerical procedure. The applied Hall current effect generates the fluid flow in the transverse direction. The flow along both axial and transverse direction enhances with thermal and solutal Grashof number and diminutions with permeability of the porous medium. Optimum magnitude of thermophoresis and Brownian motion amplifies the thermal energy of the shear thinning fluid. Concentration field exhibits the opposite nature with the nanoparticle injection rate parameter and chemical reaction parameter. Hall current parameter enhances the irreversibility of the Newtonian nanofluid.

Axisymmetric forced flow of nonhomogeneous nanofluid over heated permeable cylinders

Investigation of nanofluid properties around a cylinder is carried out for laminar steady-state axisymmetric flow. This study focuses on the porous medium with the existence of laminar and incompressible Newtonian nanofluid in two dimensions and develops an alternative model to avoid the single-phase model limitations considering the influence of Brownian motion and thermophoresis parameter for the nonhomogeneous nanofluid on permeable cylinders. Employing group method and similarity transformation, the governing mathematical model was transformed into a simpler system of ordinary differential equations. The system of equations is numerically computed. The numerical investigation included different governing parameters namely: Prandtl number , thermophoresis parameter , Brownian motion parameter , Reynolds number , and Schmidt number, Sc. Studying these parameters helps to obtain the characteristic of the flow and heat transfer. The numerical examination is illustrated in graphs to examine their effect on different fluid characteristics. Increasing Pr hurdles the nanofluid velocity, temperature, and nanoparticles concentration, while it increases the pressure due to the viscosity increment. Moreover, increasing Nt activates the thermal energy of the nanofluid which in turn increases velocity, temperature distribution, and nanoparticles concentration. A comparison between the obtained results and the previously published results indicated an excellent agreement.

Mass diffusion and radiation absorption effects on some Non-Newtonian nano fluids through aporous medium with hall current, ion slip and heat generation/absorption

The effect of mass diffusion and radiation absorption on MHD pulsatile flow of some Non Newtonian nanofluids was analysed. The influence of viscous dissipation, heat source, thermal radiation, radiation absorption and Schmidt number are accounted. For this study, we considered Eyring Powell nanofluid and Casson nanofluid. Similarity transformations are used to convert the governing partial differential equations into ordinary differential equations and then solved analytically using perturbation technique. The physical parameters impacts on velocity, temperature and concentration profiles are studied using graphs. It is worthwhile to observe that intensifying value of Radiation absorption parameter appreciates temperature profiles whereas depreciates concentration profiles. The results are presented and discussed comparatively for both Eyring Powell nanofluid and Casson nanofluid.

Insight into the relationship between unsteady Cattaneo-Christov double diffusion, random motion and thermo-migration of tiny particles

• Unsteady bidirectional flow of Newtonian nanofluid is investigated with the expressions of Cattaneo-Christov double diffusion. • Thermal convective and Nield’s conditions are in action. • Random movement and thermo-migration of tiny-particles have been used for the inspection of heat/mass transferences activities. • Keller-Box approach was adopted to solve the modeled equations. Significant impact of unsteady Cattaneo-Christov double diffusion, random motion and thermo-migration of tiny particles on thermal storage and in heat exchangers devices has attracted us to investigate the role of these thermal engineering terms in the existence of convectively heating and zero-mass flux at the bidirectionally stretchable wall. Combination of similarity expressions is adopted to transform the prevailing partial differential equations into ordinary differential equations and then solved, numerically, by using Keller-Box simulation technique. Temperature and concentration phases are discussed under the influences of involved parameters, graphically. It is detected that thermal relaxation dependent on heat flux maximizes the temperature gradient, whereas thermal relaxation dependent on mass flux minimizes the concentration gradient. It is also scrutinized that escalating choice of random motion of tiny particles provides constant temperature gradient because of Nield’s expression. Moreover, augmenting choice of thermo-migration of tiny particles enhances the concentration gradient. Furthermore, intensifying choice of unsteady factor abridges the temperature plus concentration distributions and also it condenses all the three boundary layer thicknesses.

Hydromagnetic Nanofluid Film Flow over a Stretching Sheet with Prescribed Heat Flux and Viscous Dissipation

Thermal radiative heat transfer through a thin horizontal liquid film of a Newtonian nanofluid subjected to a magnetic field is considered. The physical boundary conditions are a variable surface heat flux and a uniform concentration along the sheet. Moreover, viscous dissipation is present and concentration is assumed to be influenced by both thermophoresis and Brownian motion effects. Using a similarity method to turn the underlying Partial differential equations into a set of ordinary differential equations (ODEs) and a shooting technique to solve these equations, the skin-friction coefficient, the Nusselt number, and the Sherwood number are determined. Among other things, it is shown that large values of the thermal radiation heat transfer rate, thermal conductivity parameter, and the Brownian motion parameter can enhance the cooling of the sheet.

Thermophoretic particle deposition and heat generation analysis of Newtonian nanofluid flow through magnetized Riga plate

AbstractThe Riga surface is composed of an electromagnetic actuator that comprises a span‐wise associated array of discontinuous electrodes and an everlasting magnet mounted over a planer surface. The electro‐magneto‐hydrodynamic has an attractive role in thermal reactors, fluidics network flow, liquid chromatography, and micro coolers. Inspired by these applications, a laminar, two‐dimensional nanofluid flow with uniform heat sink‐source, thermophoretic depositions of the particles, and the Newtonian heating effect are investigated. The equations that describe the fluid motion are reduced into a system of ordinary differential equations with the help of spatial similarity variables. Numeric solutions of ordinary differential equations are executed through the Runge–Kutta–Felhberg 45 order technique via a shooting scheme. The role of various nondimensional factors on physically interesting quantities is elaborated graphically. The velocity profile rises for modified Hartmann number and decreases for porosity parameter. Thermal enhancement is high in the common wall temperature condition comparative to the case of the Newtonian heating conditions. The concentration profile is enhanced with Schmidt number, but the reverse trend is observed for the thermophoretic parameter. The rate of mass transfer is increased with Schmidt number.

A lattice Boltzmann method for single- and two-phase models of nanofluids: Newtonian and non-Newtonian nanofluids

Nanofluids play an important role in many different industries for an improvement of heat transfer. The modeling and simulation of such fluids is developing continuously. Two important models for studying nanofluids are mixture (or single-phase) and two-phase (or Buongiorno) forms, which have been examined in various ways. Non-Newtonian behavior of nanofluids (shear-thinning and viscoplasticity) has been observed in experimental tests and simulated in several studies. However, a lattice Boltzmann method (LBM), which can employ either model depending on the particular non-Newtonian constitutive equation, has not been considered to date within the suite of available numerical methods. Here, we propose a comprehensive LBM to simulate both Newtonian and non-Newtonian nanofluids. The approach has the potential to incorporate any format of extra tensor directly and is independent to the relaxation time; the upshot is that our method is appropriate for studying non-Newtonian nanofluids. The derivations for both models are presented and discussed in some detail. To evaluate the proposed method, it was compared with previous studies into a benchmark problem, natural convection in a square enclosure filled with Newtonian nanofluids and non-Newtonian fluids. Then, the applied macroscopic and LBM equations, using the power-law and viscoplastic models, for the benchmark are derived and the results are presented.

Comparative study of different non-Newtonian fluid over an elaborated sheet in the view of dual stratified flow and ohmic heat

The investigation of magnetohydrodynamic flow, heat and mass transfer of different non Newtonian nanofluid flow across a stretched sheet is presented in this article. The energy and concentration equations are analyzed with the addition of joule heating and thermophoretic effect. The thermal and solutal stratification boundary conditions are utilized at the boundary of surface. The appropriate similarity variable is used to transfer the flow modelled equations into ODEs, which are numerically solved by the utilization of Matlab bvp4c function. The involved parameters impact on the velocity, temperature, and concentration distribution are scrutinized with graphs. It is found that, the thermal layer thickness shows improved outcomes for rising values of Brownian motion parameter. Furthermore, solutal layer thickness decays for rising and Schmidt number.

A Numerical Approach to the Modeling of Thomson and Troian Slip on Nonlinear Radiative Microrotation of Casson Carreau Nanomaterials in Magnetohydrodynamics

The goal of the current work is to explore the influence of Thompson and Troian slip on the hydromagnetic microrotations of Carreau nanomaterials over a linearly stretched surface subject to NLTR, viscous dissipation, Newtonian heating, homogenous and heterogeneous reactions. Effect of non linear slip (Thompson and Troian slip) on non Newtonian nanofluid (Carreau nanofluid) subject to microrotation is the novelty of the investigation. Shooting technique is the instrumental to get appropriate numerical solution. The significant outcomes of the current study are that Casson parameter and Weissenberg number exhibit opposite results for velocity and heat transfer rate due to flow of micropolar Carreau nanofluid. Further, more and more Thompson and Troian slip yields diminution of flow velocity as well as microrotations. Amplifying Casson parameter intensifies the HTR from the stretched surface.

Insight into the dynamics of non-Newtonian carboxy methyl cellulose conveying CuO nanoparticles: significance of channel branch angle and pressure drop

Abstract Branching channels are commonly emerged in a considerable variety of engineering applications, in which most of the fluids present non Newtonian behavior, such as in chemical processes. It is noted that in the material forming process, when one suspends nanoparticles in a basic non Newtonian fluid, a completely new non Newtonian fluid is formed with different rheological characteristics from the former ones. In our present numerical research, considering the side branches inclined at varying angles, we focus on the fluid flow and heat transfer of the laminar power-law nanofluid in a rectangular branching channel under the influences of generalized Reynolds number. Both the consistency coefficient and power-law index of the non Newtonian nanofluid, different from those of the base fluid, are described by empirical formula, dependent on the nanoparticle quantity. Finite element method is applied in the research. It is found that a smaller branch angle α can cause a larger fluctuation in pressure near the branched region. Furthermore, negative pressures exist both in the main and side branch with some certain inclination angle. Above all, the new extensive results of velocity contours, temperature, concentration contours along with pressure drop of the changing rheological models provide detailed information for studies on non Newtonian nanofluids in many intricate industrial applications.

Thermo-bioconvection transport of nanofluid over an inclined stretching cylinder with Cattaneo–Christov double-diffusion

In this paper, Newtonian nanofluid flow is observed under the effects of the magnetic field, activation energy and motile microorganisms over an inclined stretchable cylinder. The magnificent aspects of nanoliquid are demonstrated by enduring the Brownian motion and thermophoresis diffusion features. Nonlinear higher order partial differential equations are transformed into first-order ordinary differential equations with suitable similarity variables. The attained sets of governing equations are then cracked by bvp4c procedure in MATLAB mathematical software. The numerical and graphical outcomes of controlling parameters such as Prandtl number, mixed convection, activation energy, thermophoresis, Brownian parameter, Biot number, Lewis number, Peclet number and motile concentration parameter against the velocity, temperature, volumetric concentration and motile concentration of nanoparticles of the fluid are discussed. The velocity is enhanced with the growth valuation in mixed convection and decay by rising variation of buoyancy ratio parameter, magnetic parameter and bio-convective Rayleigh parameter. The evolution in motile microorganisms is due to the increasing values of microorganisms Biot number. The presented data can be helpful in enhancement of manufacturing processes, biomolecules, extrusion systems applications and energy production improvement.

Radiative flow of non Newtonian nanofluids within inclined porous enclosures with time fractional derivative

An unsteady convection-radiation interaction flow of power-law non-Newtonian nanofluids using the time-fractional derivative is examined. The flow domain is an enclosure that has a free surface located at the top boundaries. Also, the geometry is filled by aluminum foam as a porous medium and the overall thermal conductivity as well as the heat capacity are approximated using a linear combination of the properties of the fluid and porous phases. Additionally, the dynamic viscosity and thermal conductivity of the mixture are expressed as a function of velocity gradients with a fractional power. Marangoni influences are imposed to the top free surface while the bottom boundaries are partially heated. Steps of the solution methodology are consisting of approximation of the time fractional derivatives using the conformable definition, using the finite differences method to discretize the governing system and implementation the resulting algebraic system. The main outcomes reveled that as the fractional order approaches to one, the maximum values of the stream function, the bulk-averaged temperature and cup-mixing temperature are reduces, regardless values of the time.

Effect of Rotation on Thermosolutal Convection in Visco-elastic Nanofluid with Porous Medium

In this paper, we studied the rotation effect on the thermosolutal convection in visco-elastic nanofluid in the presence of porous medium using Walters` (model B`). To solve the conservation equation, we used the normal mode technique and Galerkin weighted residual method. For stationary convection, the onset criterion derived analytically and experiential that visco-elastic nanofluid behaves as a regular Newtonian nanofluid. The effect of rotation, thermo-nanofluid Lewis number, thermosolutal Lewis number and solutal Rayleigh number analyze analytically and graphically.

Radiation and joule heating effects on electroosmosis-modulated peristaltic flow of Prandtl nanofluid via tapered channel

In this paper, a generalized Newtonian nanofluid in a bio-microfluidics channel due to combined effects of peristalsis and external applied electric field in the presence of thermal radiation and Joule heating is considered. The Poisson and Nernst-Planck equations are taken into account. The obtained non-linear coupled ordinary differential equations are simulated numerically. The impacts of several parameters under the applied electric field on velocity, temperature, concentration, trapping isothermal lines, Nusselt, and Sherwood numbers are presented graphically. It is observed that the number of isothermal lines increases with the electro-osmotic parameter thermophoresis parameter and Brownian motion parameter while perter out with thermal radiation. The results are helpful to design the micro pumps/chips used in medical engineering and improved the thermal efficiency and the durability of microchip cooling devices.