Buongiorno Nanofluid Model Research Articles

Unsteady 3D mixed convection flow of a chemically reactive Oldroyd‐B nanofluid configured by a periodically accelerated surface

AbstractFundamental developments in nanotechnology have attracted the attention of scientists towards the interaction of nanoparticles due to their fascinating applications in thermal engineering and solar energy systems. Convinced by such motivating applications, the current research project addresses the utilization of nanoparticles in the unsteady three‐dimensional chemically reactive flow of an Oldroyd‐B fluid induced by a bidirectional oscillatory stretching surface. The effects of mixed convection are also considered here. The prime features of the nanofluid namely thermophoresis and Brownian motion characteristics are explored by introducing the famous Buongiorno's nanofluid model. The relevant equations for the formulated theoretical model have been reduced by the appropriate transformations for which the analytic solution is deliberated via the homotopic technique. Later on, a complete graphical analysis for distinct flow parameters is deliberated for dimensionless velocities, concentration, and temperature distributions with the relevant physical implications. Moreover, stimulating physical quantities like local Nusselt and Sherwood numbers are numerically calculated and discussed. The study emphasizes that decreasing variation in both components of velocities has been reported with an increment of relaxation time, while the impact of the retardation time constant is quite opposite. It is further claimed that the velocity distribution has an increasing tendency in the horizontal direction for a higher buoyancy ratio and mixed convection parameters. Moreover, an increment in thermophoresis parameter enhances both temperature and concentration distributions.

A comparative description on time-dependent rotating magnetic transport of a water base liquid H[formula omitted]O with hybrid nano-materials Al[formula omitted]O[formula omitted]-Cu and Al[formula omitted]O[formula omitted]-TiO[formula omitted] over an extending sheet using Buongiorno model: Finite element approach

In the present study, we investigate a comparative study of MHD rotational flow of hybrid-nanofluids (Al2O3-Cu/ water and Al2O3-TiO2/ water) over a horizontally elongated plane sheet. The principal objective is concerned with the enhancement of thermal transportation. The novelties of the present-study are (i) a comparative study of two hybrid nanofluids with hybrid-base fluid and different shape factors, (ii) the Tiwari and Das nanofluid model is implemented together with Buongiorno nanofluid model, and (iii) the finite element approach for this elaborated problem. The three-dimensional conservation equations for mass, momentum, energy, and species (nanoparticle) diffusion, are normalized into a system of two-dimensional dimensionless boundary layer equations, using appropriate scaling transformations. The variational finite element procedure is harnessed and coded in Matlab script to obtain the numerical solution of the coupled non-linear partial differential problem. A detailed evaluation of the effects of the governing physical parameters on the velocity components, temperature, and nanoparticle concentration via graphical plots is conducted. Both the primary and secondary velocities are smaller in values for hybrid-phase Al2O3-Cu than that of hybrid-phase Al2O3-TiO2, but the temperature and nanoparticles concentration distribution is higher for the hybrid-phase Al2O3-Cu. It is observed that higher inputs of the parameters for thermophoresis, Brownian motion, shape factors, and volume fraction of ϕ2 made significant improvements in the temperature. The varying patterns of skin friction coefficients (x, y-directions), Nusselt number, and Sherwood number are computed to reveal the physical nature of this study. The present findings manifest a reasonable comparison to their existing counterparts.

Analysis and modeling of magnetic dipole for the radiative flow of non‐Newtonian nanomaterial with Arrhenius activation energy

The present investigation deliberates the impact of the magnetic dipole for the flow of non‐Newtonian Williamson nanoliquid by considering the thermal radiation and chemical reaction defined by the Arrhenius model. The flow model is established by incorporating the well‐known Buongiorno's nanofluid model, and as a result, Brownian motion and thermophoretic diffusion are assimilated in mathematical modeling. The heat transportation process is accomplished by thermal radiation, heat generation owing to internal energy generation/absorption of the fluid, and viscous dissipation. The coupled nonlinear mathematically formulated partial differential equations (PDEs) are metamorphosed into the ordinary differential equations (ODEs) through the transformation. The bvp4c method is utilized to obtain the solution of formulated ODEs together with the additional conditions at the boundary. The impact of pertinent flow characteristics on temperature, velocity, and concentration profiles is outlined graphically. Also, the strength of energy, surface drag force, and mass transport are calculated and formed in the tabular form. The outcomes show that a rise in activation energy causes fluid concentration to increase. Velocity gets reduced with the increment in either ferrohydrodynamic interaction factor or Weissenberg number.

Thermal variable conductivity features in Buongiorno nanofluid model between parallel stretching disks: Improving energy system efficiency

In present investigation, the axisymmetric analysis for the Casson nano-material has been analyzed due to two parallel stretchable disks. The novel thermophoresis and Brownian aspects of nanofluid are studied by using Buongiorno nanofluid model. Similarity transformations are applied on the system of governing equations that renovate it into the problem into proper dimensionless form. The homotopic procedure is suggested for the determination of solution. The role of numerous parameters on dimensionless velocity and temperature are observed in very effective way. To study the effect of Brownian motion and thermophoresis diffusion parameter, Buongiorno model is adopted. Radial and axial velocity profile has increasing behavior for stretching ratio and Casson parameter. As the value of Biot number and thermophoresis parameter enhanced, the concentration profile also enhances and concentration profile declines due to increase in value of Brownian motion parameter. Temperature profile decreases as the value of Reynolds number and Prandtl number increased. The values of Sherwood number, Nusselt number and Skin friction are calculated at upper and lower disk to understand the behavior of stretching disks.

Thermophoresis particle deposition analysis for nonlinear thermally developed flow of Magneto-Walter’s B nanofluid with buoyancy forces

In this study, we have discussed thermophoresis particle deposition effects under the action of both pressure and buoyant forces flow of magneto-Walter’s B nanofluid induced by a stretched surface. The Buongiorno nanofluid model is employed to analyze the dynamic impact of thermophoretic dispersion and Brownian motion. The effects of chemical reaction, Joule heating and non-linear radiation relations are also incorporated. The analysis has been performed in view of solutal and heat convective boundary constraints. The analytical technique namely homotopy analysis scheme followed to solve the resulting non-linear governing equations. The behavior of velocity, temperature and concentration profiles are observed graphically. The physical consequences for all physical parameters are justified. It is noted that heat thermal Biot number, thermophoretic constant and viscoelastic parameter increases the nanofluid temperature and concentration. A decaying concentration profile is noted for Schmidt number.

Flow and thermal management of MHD Cross nanofluids over a thin needle with auto catalysis chemical reactions

This research work concerns the investigation of electrically conducting stagnation point flow, heat and mass transport of magneto-Cross nanofluids towards a moving and stretched surface of thin needle. The Buongiorno nanofluid model is incorporated to model the governing expressions. The flow is conducted electrically and generated through stretching impact. Internal diffusion of particle, homogenous–heterogeneous reactions and radiative heat flux effects are utilized to examine the behavior of heat and mass transport on the surface of thin needle. Suitable similarity variables and boundary layer approximations are used to turn into dimensionless one. After that, numerical outcomes are computed by a Shooting method (bvp4c) package in MATLAB. The incentives of sundry relevant parameters on the flow field, skin friction coefficient, heat transfer rate, temperature field and concentration distribution are portrayed via graphical tactic and have been elucidated in detail. The outcomes indicate that the temperature distribution is more versus rising values of radiative heat flux, magnetic parameter and Eckert number.

Entropy generation analysis in magnetohydrodynamic Sisko nanofluid flow with chemical reaction and convective boundary conditions

The main emphasis of the present study is to analyze the novel feature of entropy generation in the flow and heat transfer of Sisko nanofluid over a stretching sheet in the presence of the magnetic field, chemical reaction, and convective boundary conditions. Buongiorno's nanofluid model is used to consider the effect of Brownian diffusion and thermophoresis. The governing Sisko nanofluid flow equations comprising the momentum, nanoparticle volume fraction, and energy are reduced to nonlinear differential equations by utilizing appropriate similarity variables. The numerical solution of nonlinear coupled differential equations is obtained using the finite difference scheme in combination with the quasilinearization technique. The impact of different physical parameters on velocity, nanoparticle volume fraction, and temperature is presented graphically. The variation in entropy generation and Bejan number with different pertinent parameters that characterize the entropy generation phenomenon for the flow of Sisko nanofluid is discussed. The obtained results indicate that the entropy generation enhances with an increase in the magnetic parameter, Brinkman number, and thermal Biot number while reduces with the Sisko material parameter. Moreover, the behavior of mass and heat transfer rates is displayed through the Brownian diffusion parameter and thermophoresis parameter. The analysis of entropy generation minimization has crucial applications in the industrial heat transfer problems, solar heat exchanger, turbomachinery designing, LED‐based spotlights, designing of air‐cooled gas turbine blades, cooling in nuclear fuel rods, rotating reactors, in chillers, air separators, and so forth. Furthermore, entropy generation with MHD flow has applications in MHD generators, nuclear reactors, flow meters, micropumps, power plants, and so forth.

Investigation of viscous dissipation and entropy generation in third grade nanofluid flow over a stretched riga plate with Cattaneo-Christov Double Diffusion (CCDD) model

Fluid flow and heat transport by a stretched surface is most important and significant area of research in mechanical and industrial engineering due to numerous applications. The influence of heat transport is seen in the field of polymer processing, metallurgy and chemical engineering, manufacturing of artificial films, food stuff processing, aerodynamics extrusion of plastic sheets, hot rolling, glass fiber production, metal spinning, metal extrusion, drawing of plastic films and wires and paper production. In view of the above applications, we have modeled two-dimensional, steady and incompressible flow of non-Newtonian fluid (third grade) over a stretched Riga surface with Cattaneo-Christov Double Diffusion (CCDD) model. Stagnation point flow is considered and the flow is generated due to stretched Riga surface. Furthermore, Cattaneo-Christov Double Diffusion concept is used instead of Fourier’s and Fick’s laws to model the energy and concentration equations. Important slip mechanisms of Buongiorno nanofluid model i.e., Brownian motion and thermophoresis diffusion are considered for the transportation of heat and mass transfer. Nield condition is imposed at the stretched boundary surface. Total entropy rate is calculated and discussed through second law of thermodynamics and important pertinent flow parameters. Appropriate similarity variable leads to system of ordinary ones and total residual error and convergence rate are obtained via Optimal Homotopy Analysis Method (OHAM). The influence of parameters on the velocity, temperature, concentration and skin friction coefficient are discussed graphically.

Modeling and dual solutions for magnetized mixed convective stagnation point flow of upper convected Maxwell fluid model with second‐order velocity slip

In the present work, we have studied a numerical solutions of MHD stagnation point flow of nanofluid over a stretching/shrinking sheet with mass suction condition. We have used the upper convected Maxwell (UCM) fluid model for the development of momentum equation and utilized it to explore the characteristics of elasticity of this model. We used the Buongiorno nanofluid model to develop the equations for the present problem. The governing flow, energy, and concentration equations are changed into the ordinary differential equations by means of suitable transformation. The subsequent ordinary ones are solved numerically using bvp4c scheme in MATLAB. The combined results of buoyancy forces, double slip (first‐ and second‐order slip), and elasticity have been investigated, and the influence of various flow parameters such as Hartmann number, suction parameter, and stretching/shrinking parameter on the skin friction coefficient, local Nusselt number, Sherwood number, and streamlines is studied and exposed through graphs. It is found that mass suction parameter and elasticity of UCM fluid increase the range of buoyancy forces for the existence of dual solutions. Also, buoyancy force increases the range of stretching/shrinking parameter where solution exists.

Radiative unsteady hydromagnetic 3D flow model for Jeffrey nanofluid configured by an accelerated surface with chemical reaction

AbstractThe current exploration reveals the unsteady three‐dimensional flow of Jeffrey nanofluid over a bidirectional oscillatory stretching surface. The Brownian motion and thermophoresis phenomenon has been scrutinized by utilizing Buongiorno's nanofluid model. The heat transfer analysis is carried out in the presence of thermal radiation and heat generation/absorption features. Furthermore, chemical reaction and magnetic effects are also deliberated. The flow has been generated by a bidirectional periodically accelerated heated surface. The formulated nonlinear problem is condensed into a dimensionless form via apposite transformations, and then analytic series solution is computed via homotopic technique. Comprehensive graphical evaluations for numerous prominent flow constants on associated profiles are performed. In addition, the tabulated numerical calculations for the local Nusselt and Sherwood numbers are also presented. The current analysis reported that both components of velocities have an increasing tendency for higher Deborah number, whereas an adverse influence is observed for the ratio of relaxation and retardation times parameter. Moreover, the concentration profile diminishes for the increasing variation of the chemical reaction parameter.

Mixed convective flow of an Oldroyd-B nanofluid impinging over an unsteady bidirectional stretching surface with the significances of double stratification and chemical reaction

The numerous applications of non-Newtonian nanofluids in engineering, geothermal and industrial processes motivated us to formulate a comprehensive model for unsteady 3D flow of an Oldroyd-B nanomaterial. Brownian motion and thermophoresis characteristics are also accommodated through a Buongiorno nanofluid model. Moreover, assessments of thermal stratification, chemical reaction, solutal stratification, mixed convection, and prescribed heat source are also elucidated in the combinations of momentum, energy, and concentration equations. The transformed system of ODEs is tackled by homotopy analysis method. A comparison benchmark for limited cases is also constructed to confirm the correctness of whole parametric exploration. It is scrutinized through present communication that intensifying values of Prandtl factor, unsteady factor, heat distribution indices, thermal stratification constraint, mixed convective parameter, and Deborah number for time retardation diminish the temperature of the nanomaterial. Also, escalating amounts of Lewis number, chemically reactive species, Brownian motion parameter, and solutal stratification constraint reduce the concentration profile.

Significances of prescribed heat sources on magneto Casson nanofluid flow due to unsteady bi-directionally stretchable surface in a porous medium

In this communication, bidirectional flow of Casson nanomaterial driven by an unsteady moveable surface in the region of boundary layer is analyzed. Moreover, the significances of porous space, magnetic field, prescribed surface temperature (PST), and prescribed surface heat flux are also incorporated. Furthermore, the aspects of Brownian motion and thermophoresis are also comprised through Buongiorno nanofluid model. Governing equations are firstly transformed into system of ordinary differential equations by using a suitable combination of variables, and then computational assessment is made through Keller-Box method. Graphical illustrations for temperature distribution, concentration distribution, local Nusselt number and local Sherwood number against escalating amounts of pertinent parameters are presented. It is observed that escalating amounts of unsteady parameter and temperature controlled indices reduce the temperature distribution, as well as the concentration distribution. It is also observed that increasing amounts of Casson parameter enhances the rate of heat transfer, and reduces the rate of mass transfer for PST case. Finally, a comparison benchmark for limited case has been presented to validate the present methodology.

Fully developed second order velocity slip Darcy-Forchheimer flow by a variable thicked surface of disk with entropy generation

This research communication deals with nonlinear mixed convection and entropy generation analysis of second order velocity slip flow of viscous fluid by a variable thicked stretchable surface of disk. The stretchable disk were subjected to convective boundary conditions at the surface for heat and mass transport. A Darcy-Forchheimer relation is considered and Buongiorno nanofluid model is used in the mathematical modeling. Total entropy rate subject to four types of irreversibilities i.e., heat transfer, fluid friction, chemical reaction or concentration and joule heating is calculated via second law of thermodynamics. Binary chemical reaction with Arrhenius activation energy is also considered. The governing expressions relevant to both fully developed laminar flows (hydro-dynamically and thermally) were solved analytically through homotopy analysis method. The computational solutions for the velocity field, temperature distribution, concentration distribution, entropy generation rate, skin friction coefficient, Bejan number, Nusselt number in terms of different parameters like stretching parameter, second order velocity slip, mixed convection parameter, magnetic parameter, thermal biot number, Eckert number, activation energy parameter and solutal biot number were obtained. The obtained outcomes indicate that an increase in second order velocity slip and mixed convection parameters leads to a decrease in velocity components i.e., axial and radial. Temperature distribution is strongly affected by the rising values of Eckert number and thermal biot number and show increasing behavior. The engineering curiosity like skin friction coefficient and Nusselt and Sherwood numbers are calculated numerically and examined through tabular form. The results of present communication are helpful in deep understanding of flow and heat and mass transports by a variable thicked surface of stretchable disk and more thermally well-organized microfluidic devices which use viscous fluids

Significances of blowing and suction processes on the occurrence of thermo-magneto-convection phenomenon in a narrow nanofluidic medium: A revised Buongiorno's nanofluid model

In this numerical examination, the thermal stability of an electrically conducting nanofluid is deliberated comprehensively by considering the presence of an externally applied magnetic field along with an imposed vertical throughflow. Additionally, this thin nanofluidic layer is supposed to have a Newtonian rheological behavior, heated from below, and confined horizontally between two permeable rigid plates of infinite extension. Herein, the governing conservation equations are strengthened realistically by the revised version of the Buongiorno's mathematical model, in which the vertical component of the mass flux of solid nanoparticles is presumed to vanish entirely at the horizontal permeable boundaries. After specifying the basic state of the present nanofluid problem, the linear stability theory and normal mode analysis technique are applied properly to obtain the principal stability equations. Finally, the eigenvalue problem derived analytically is tackled thereafter numerically via the Chebyshev-Gauss-Lobatto Spectral Method (CGLSM), in which the thermal Rayleigh number is chosen as an eigenvalue. As a main result, it was demonstrated that the throughflow effect exhibits a dual behavior on the complex dynamics of the system. However, the excreted magnetic field has always a stabilizing impact on the nanofluidic medium.

Numerical simulation for MHD Darcy–Forchheimer three-dimensional stagnation point flow by a rotating disk with activation energy and partial slip

The Buongiorno nanofluid model is utilized to scrutinize the impacts of important slip mechanisms, i.e., thermophoresis diffusion and Brownian momentum on the Darcy–Forchheimer three-dimensional stagnation point flow of viscous fluid towards a flat surface with multi slips (velocity, temperature, concentration). The thermo-physical and experimental correlations for the thermal conductivity, density and dynamic viscosity of nanoliquid are implemented in the governing expressions. Nanoliquids are mostly utilized in the continuous phase liquid to enhance their thermal characteristics as coolants in transport equipment, i.e., electronic cooling system, heat exchangers and radiators. Heat transport subject to flat plate has been examined by numerous analyst. Appropriate similarity transformations which is derived from Lie point symmetry is incorporated to alter the system of governing equation into ordinary one. The transformed system is solved numerically through bvp4v (built-in-shooting) technique. The influences of important flow parameters on the dimensionless temperature, velocity, Nusselt number, concentration, wall shear stress and Sherwood number are plotted graphically and tabular form.

Influence of Soret and Dufour on forced convection flow towards a moving thin needle considering Buongiorno’s nanofluid model

This article concerns the study of forced convection flow, heat and mass transfer near a moving slender needle using the Buongiorno nanofluid model. Soret and Dufour impacts are analyzed to study the thermo-diffusion and diffusion-thermo impacts on the flow. The governing boundary layer equations are turned into a dimensionless one with the assistance of similarity transformations. After that those ordinary differential equations are computed by a bvp4c package in MATLAB program. Subsequently, the influences of relevant variables on the coefficient of skin friction, heat and mass transfer rate, momentum, temperature and concentration fields are depicted through the graphical approach and have been interpreted in detail. Extracted outcomes are also authenticated with the existing articles. The multiple solutions are noticed to show up in particular ranges of several parameters. The stability of solutions is conducted to find which of the solution gained is linearly stable. The results indicate that the solution for the upper branch is stable, while the solution for the lower branch is unstable. The outcomes also revealed that the percentage of heat and mass transmission rate diminishes by 40.43% and 31.41%, respectively, with the increment in the needle thickness from b=0.1 to b=0.2.

Von Kármán rotating flow of Maxwell nanofluids featuring the Cattaneo-Christov theory with a Buongiorno model

This research paper analyzes the transport of thermal and solutal energy in the Maxwell nanofluid flow induced above the disk which is rotating with a constant angular velocity. The significant features of thermal and solutal relaxation times of fluids are studied with a Cattaneo-Christov double diffusion theory rather than the classical Fourier’s and Fick’s laws. A novel idea of a Buongiorno nanofluid model together with the Cattaneo-Christov theory is introduced for the first time for the Maxwell fluid flow over a rotating disk. Additionally, the thermal and solutal distributions are controlled with the impacts of heat source and chemical reaction. The classical von Karman similarities are used to acquire the non-linear system of ordinary differential equations (ODEs). The analytical series solution to the governing ODEs is obtained with the well-known homotopy analysis method (HAM). The validation of results is provided with the published results by the comparison tables. The graphically presented outcomes for the physical problem reveal that the higher values of the stretching strength parameter enhance the radial velocity and decline the circumferential velocity. The increasing trend is noted for the axial velocity profile in the downward direction with the higher values of the stretching strength parameter. The higher values of the relaxation time parameters in the Cattaneo-Christov theory decrease the thermal and solutal energy transport in the flow of Maxwell nanoliquids. The higher rate of the heat transport is observed in the case of a larger thermophoretic force.

Analysis of activation energy and entropy generation in mixed convective peristaltic transport of Sutterby nanofluid

Peristalsis of nanofluid is significant in cancer treatment, ulcer treatment and industrial equipment. This study simulated the MHD peristaltic transport of Sutterby nanofluid with mixed convection and Hall current. Partial slip and convective conditions are imposed for flexible channel walls. Energy and concentration equations are modeled by considering the effects of Joule heating, thermal radiation, viscous dissipation and activation energy. Buongiorno nanofluid model is employed which features thermophoresis and Brownian movement aspects. The resulting nonlinear system of equations is numerically solved after employing the large wavelength and small Reynolds number supposition. Graphical analysis for the velocity, temperature, concentration, heat transfer coefficient and entropy generation is analyzed. It is observed that velocity has opposite behavior for mixed convection parameters. Temperature and heat transfer rate enhanced for Brownian movement and thermophoresis parameters. Concentration rises against larger activation energy and radiation variables. Further entropy declines against higher diffusion parameter.

Significance of activation energy in radiative peristaltic transport of Eyring-Powell nanofluid

In this article we illustrate the features of first-order chemical reaction and activation energy on MHD peristaltic transport of Eyring-Powell nanofluid. Modeling and analysis in the presence of heat generation/absorption are studied. Energy equation is modeled by considering thermal radiation, Joule heating and dissipation. Velocity slip is imposed on flexible channel walls. Heat convective condition is analyzed. For mathematical modeling the Buongiorno nanofluid model is used. Thermophoresis and Brownian diffusion are under consideration. The governing partial differential equations are first reduced to the system of ordinary differential equations by applying relevant transformations and then shooting technique is used to obtain the numerical results. Relevant problem for low Reynold number and long wavelength is reduced. Numerical results for velocity, temperature, concentration, heat transfer coefficient and trapping are analyzed. Expressions for coefficient of skin friction, Nusselt and Sherwood numbers at the channel wall are examined. Influence of Eyring-Powell variables on velocity shows opposite behavior. Velocity of fluid increases against velocity slip parameter. Temperature increases for higher values of thermophoresis and Brownian motion while it decays against thermal Biot number. Concentration enhances for higher values of radiation and activation energy variables. Heat transfer coefficient is an increasing function of heat generation.

Melting heat transfer analysis of electrically conducting nanofluid flow over an exponentially shrinking/stretching porous sheet with radiative heat flux under a magnetic field

AbstractModern magnetic nanomaterial processing operations are progressing rapidly and require increasingly sophisticated mathematical models for their optimization. Stimulated by such developments, in this paper, a theoretical and computational study of a steady magnetohydrodynamic nanofluid over an exponentially stretching/shrinking permeable sheet with melting (phase change) and radiative heat transfer is presented. Besides, wall transpiration, that is, suction and blowing (injection), is included. This study deploys Buongiorno's nanofluid model, which simulates the effects of the Brownian motion and thermophoresis. The transport equations and boundary conditions are normalized via similarity transformations and appropriate variables, and the similarity solutions are shown to depend on the transpiration parameter. The emerging dimensionless nonlinear coupled ordinary differential boundary value problem is solved numerically with the Newton‐Fehlberg iteration technique. Validation with special cases from the literature is included. The increase in the magnetic field, that is, the Hartmann number, is observed to elevate nanoparticle concentration and temperature, whereas it dampens the velocity. Higher values of the melting parameter consistently decelerate the boundary layer flow and suppress temperature and nanoparticle concentration. A higher radiative parameter strongly increases temperature (and thermal boundary layer thickness) and weakly accelerates the flow. The increase in the Brownian motion reduces nanoparticle concentrations, whereas a greater thermophoretic body force strongly enhances them. The Nusselt number and Sherwood number are observed to be decreased with an increasing Hartmann number, whereas they are elevated with a stronger wall suction and melting parameter.