Mixed Convection Flow Of Nanofluid Research Articles

FDM analysis for nonlinear mixed convective nanofluid flow with entropy generation

This analysis is concerned with unsteady Darcy-Forchheimer flow of nanomaterial by a stretching sheet. Heat transfer is carried out in presence of nonlinear mixed convection. Brownian motion and thermophoresis diffusion describe nanomaterial characteristics. Further magnetic field and viscous dissipation impacts are considered. By choosing suitable variables problem related expressions (PDEs) are transformed into dimensionless PDEs. These PDEs are then tackled through finite difference scheme. Entropy generation, skin friction, mass transfer rate and heat transfer rate are elaborated for involved parameters. Velocity enhances with increment in buoyancy variable and time while it reduces via higher Forchheimer number and porosity parameter. Temperature of the fluid decays with larger time while it boosts with an increment in Eckert number and nonlinear convection parameter. Higher values of Schmidt number lead to decay in concentration while it intensifies against higher thermophoretic diffusion parameter and time. Entropy production rate boosts against Prandtl and Eckert numbers while it is controlled via higher temperature ratio and volume ratio parameters.

Non-similarity solutions of radiative stagnation point flow of a hybrid nanofluid through a yawed cylinder with mixed convection

In this new-fangled research, the mixed convective stagnation point flow of a hybrid nanofluid over a yawed cylinder with radiation impact is considered. In reality, the perception of mixed convection in the study of yawed cylinder rises in heat exchangers. To explore the heat diffusion through the system of mixed convection, the mathematical problem is formed in the form of partial differential equations which are coupled and nonlinear. A solution technique is applied and described for indulgencing non-similar thermal boundary layers. The non-similar terms involving in the transformed equations are held without approximations. The non-similar equations are solved numerically using the bvp4c technique. The exploration divulges numerous significant results involving yaw angle, hybrid nanoparticle volume fraction, mixed convection, radiation, and non-similarity phenomena. The impact of the yaw angle in enhancing the velocity of the hybrid nanofluid in the span-wise and chord-wise directions in the aiding buoyancy flow and decelerating in the opposing flow, while the contrary behavior is noticed for the dimensionless temperature profile. Also, the hybrid nanoparticles reduce the velocity in both directions in case of assisting as well as opposing flow, whereas the dimensionless temperature augments.

Mathematical Analysis of Thermal Energy Distribution in a Hybridized Mixed Convective Flow

The mixed convective flow of hybrid nanofluid (SWCNT-MWCNT/EG) containing micropolar fluid past a Riga surface embedded in porous medium is explored in detail throughout this study. In the momentum equation, the Darcy Forchheimer effect is used. The heat transfer phenomenon is exploited with viscous dissipation and thermal stratification over a non-Fourier heat flux model. PDEs are transformed into the necessary governing equations using transformations. The numerical results of non-linear governing equations are collected using Matlab function bvp4c. Graphical representations of the effects of relevant parameters on velocity, skin friction, and temperature are shown. The comparison of simple nanofluid and hybrid nanofluid is discussed in graphs. The temperature field is higher for hybrid nanofluid than simple nanofluid when solid volume fraction enhances. With increasing solid volume fraction, porosity parameter, and mixed convection parameter, the axial friction factor rises. The momentum boundary layer is inversely proportional to the slip parameter, Hartman number, variable viscosity and the porosity parameter.

MHD Mixed Convection Nanofluid Flow over Convectively Heated Nonlinear due to an Extending Surface with Soret Effect

The aim of this paper is to investigate the flow of MHD mixed convection nanofluid flow under nonlinear heated due to an extending surface. The transfer of heat in nanofluid subject to a magnetic field and boundary conditions of convective is studied to obtain the physical meaning of the convection phenomenon. The governing partial differential equations (PDEs) of the boundary layer are reduced to ordinary differential equations (ODEs) considering a technique of the transformation of similarity. The transformed equations are solved numerically considering the technique of an efficient numerical shooting applying the Runge–Kutta technique scheme from the fourth-fifth order. The results corresponding to the dimensionless speed, temperature, concentration profiles, and the Nusselt number reduced, and the Sherwood numbers are presented by figures to display the physical meaning of the phenomena. A comparison has been made between the obtained results with the previous results obtained by others and agrees with them if the new parameters vanish. The results obtained indicate the impacts of the nondimensional governing parameters, namely, magnetic field parameter M, Soret number Sr, heat source λ, thermal buoyancy parameter λ T , and solutal buoyancy parameter λ C on the flow, temperature, and concentration profiles being discussed and presented graphically.

Closure to “Computational Analysis for Mixed Convective Flows of Viscous Fluids With Nanoparticles” (Farooq, U., Lu, D. C., Ahmed, S., and Ramzan, M., 2019, ASME J. Therm. Sci. Eng. Appl., 11(2), p. 021013)

Abstract The authors regret in the published paper referenced above and agree with the discussion by Pantokratoras (2019, “Discussion: “Computational Analysis for Mixed Convective Flows of Viscous Fluids With Nanoparticles” (Farooq, U., Lu, D. C., Ahmed, S., and Ramzan, M., 2019, ASME J. Therm. Sci. Eng. Appl., 11(2), p. 021013),” ASME J. Therm. Sci. Eng. Appl., 11(5), p. 055503). In this Closure, the non-similar mathematical model is developed to describe the mixed convective nanofluid flow over vertical sheet which is stretching at an exponential rate. In the published article referenced above, similarity transformations are utilized to convert the governing nonlinear partial differential equations (PDEs) into ordinary differential equations (ODEs). The important physical numbers such as magnetic field (M2), Brownian motion parameter (Nb), thermophoresis (Nt), Eckert number (Ec), ratio of mass transfer Grashof to heat transfer Grashof (N), buoyancy parameter (λ), and Reynolds number (Re) appearing in the dimensionless ODEs are still functions of coordinate “x”; therefore, the problem is non-similar. In this corrigendum, the non-similar model is developed by using ξ(x) as non-similarity variable and η(x, y) as pseudo-similarity variable. The dimensionless non-similar model is numerically simulated by employing local non-similarity via bvp4c. The graphical results show no change in behavior. The important thermal and mass transport quantities such as Nusselt number and Sherwood number have been computed for the non-similar model, and results are compared with the published article.

Mixed convective stagnation point flow of a hybrid nanofluid toward a vertical cylinder

Purpose The purpose of this paper is to numerically analyze the stagnation point flow of Cu-Al2O3/water hybrid nanofluid with mixed convection past a flat plate and circular cylinder. Design/methodology/approach The similarity equations that reduced from the boundary layer and energy equations are solved using the bvp4c solver. The duality of solutions is observed within the specific range of the control parameters, namely, mixed convection parameter λ, curvature parameter γ and nanoparticles volumetric concentration ϕ1 for alumina, while for copper ϕ2. The stability analysis is also designed to justify the particular solutions’ stability. Additionally, the idea to obtain the solution for large value of λ and γ is also presented in this paper. Findings Two solutions exist in opposing and assisting flows up to a critical value λc where λc lies in the opposing region. An upsurge of the curvature parameter tends to extend the critical value (delay the separation process), whilst increase the heat transfer performance of the working fluid. Meanwhile, the application of hybrid Cu-Al2O3/water nanofluid also can decelerate the separation of laminar boundary layer flow and produce higher heat transfer rate than the Cu–water nanofluid and pure water. Originality/value The results are new and original. This study benefits to the other researchers, specifically in the observation of the fluid flow characteristics and heat transfer rate of the hybrid nanofluid. Also, this paper features with the mathematical formulation for the solution with large values of λ and γ.

Mixed convective flow and heat transfer of hybrid nanofluid impinging obliquely on a vertical cylinder

Flow and heat transportation in hybrid nanofluid, impinging obliquely on a vertical cylinder, are investigated numerically in this communication. Silver and aluminium oxide nanoparticles having stable and relatively high thermal conductivity, with pure water as base fluid, are used in the analysis. The non-linear coupled partial differential equations are transformed into ordinary differential equations using suitable transformations. An implicit finite difference method is used to approximate the velocities and temperature for particular values of the various parameters and their effects are emphasised graphically. The tabular data are documented to compare the heat transfer rate for pure water silver/water nanofluid, aluminium/water nanofluid and silveraluminiumwater hybrid nanofluid. It is observed that heat transfer rate increases by increasing the curvature of the stretching cylinder and solid volume fraction of nanoparticles and for hybrid nanofluid it has a larger magnitude than that of water, nanofluid and nanofluid.

Unsteady mixed convective flow of nanofluid with arbitrary‐shaped nanoparticles over a shrinking sheet

AbstractThe present study describes the unsteady mixed convection nanofluid flow past a vertical shrinking porous surface in occurrence of slips and heat source/sink. Applying proper transformations, the foremost differential equations which are partial in nature are changed into non‐linear differential equations which are ordinary in nature. With the support of Runge–Kutta method, shooting technique is used to find out the numerical solutions of the system of equations stated above. The effects of diverse leading parameters like unsteady parameter, velocity slip parameter, suction/injection parameter, thermal slip parameter, and heat source/sink parameter are offered and explained physically. Also, the coefficient of skin friction and rates of surface heat and mass transport for a number of parameters are investigated numerically.

Numerical Simulations of Hydromagnetic Mixed Convection Flow of Nanofluids inside a Triangular Cavity on the Basis of a Two-Component Nonhomogeneous Mathematical Model

Nanofluids have enjoyed a widespread use in many technological applications due to their peculiar properties. Numerical simulations are presented about the unsteady behavior of mixed convection of Fe3O4-water, Fe3O4- kerosene... | Find, read and cite all the research you need on Tech Science Press

Comparative mathematical study of MHD mixed convection flow of nano-fluids in the existence of porous media, heat generation and radiation through upstanding equidistant plates

Intention of current work is to examine impacts of radiation and heat generation in time-dependent MHD assorted convection flow of nano-fluids along a erect channel concluded permeable medium. Tetrad kinds of nanofluids were considered (i) Water based – Cu (ii) Water created – Ag (iii) Water created – Al2O3 (iv) Water created – TiO2. Water is occupied as convectional base liquid and Ag, Cu, Al2O3, TiO2 elements are combined in this base liquid. Care in attention the clustering and Brownian motion of Kleinstreuer, Koo and nanoparticles sample is applied. The chief features of the nano-fluids have better thermo physical cretic such as high thermal conductivity, minimal clogging in movement passageway, long term stability and homogeneity. The main border layer calculations are expressed and diminished to a set of ordinary differential equations using perturbation method. Analytical resolutions are gotten for velocity and temperature, deliberated and proper outcomes are exposed through graphs. The conclusion of the work may be valuable for usage in the arena of science & Technology. Present study emphasis on comparative mathematical study of MHD mixed convection flow of four type of nano-fluids. This comparative study is carried out in the presence of porous media, heat generation and radiation effect.

Mixed convective nanofluid flow over a non linearly stretched Riga plate

The present article concentrates on the heat and mass transfer characteristics of a mixed convective flow of an electrically conducting nanofluid past a slender Riga plate in the presence of viscous dissipation and chemical reaction. The heat and mass transfer characteristics are analyzed by a zero nanoparticle mass flux and convective boundary conditions. The thermophoretic and Brownian aspects for nanoliquid are proposed using Buongiorno's relations. The similarity quantities are utilized to obtain dimensionless forms of flow field equations. The resulting coupled nonlinear equations associated with the constituted boundary assumptions analytically proceed via optimal homotopy analysis method (OHAM). Various parameters causing the change in distributions of velocity, temperature, and concentration are graphically explained with relevant physical references. One of the important observations of the present study is, for higher values of modified Hartmann number the velocity profile increases and temperature profile supreses and it is interesting to note that the contemporary numerical simulations offer confirmable accuracy in the existing literature, which authenticates the novelty of current investigation.

MHD mixed convective flow of power-law nanofluid in a lid-driven cavity with heat generation and chemical reaction effects: Buongiorno's model

The two-dimensional laminar MHD mixed convective flow of non-Newtonian power-law nanofluid in a lid-driven cavity with the presence of heat generation and chemical reaction effects is analysed. The nanofluid incorporates the effects of Brownian motion and thermophoresis using Buongiorno’s model. The governing equations in a vector form are transformed into non-dimensional form. Then, the dimensionless equations are solved numerically by finite element method (FEM) using automated solution technique which is FEniCS. The effects of different physical parameters on velocity, temperature, and nanoparticles volume fraction profiles are presented and discussed in this paper.

Nonlinear mixed convective nanofluid flow about a rough sphere with the diffusion of liquid hydrogen

In this paper, a study of steady nonlinear mixed convective nanoliquid flow about a rough sphere with the diffusion of liquid hydrogen is considered. The governing equations are first modelled from the current physical problem, and then, suitable non-similar transformations are applied to non-dimensionalize the model equations. The resultant nonlinear dimensionless equations are linearized by using the Quasilinearization technique. The resulting linear system of differential equations are approximated by finite differences to obtain numerical solutions. The impacts of different physical parameters involved in the problem, such as the distribution of velocity, temperature, nanoparticle volume fraction and species concentration are studied. The analysis of wall gradients is carried out, which discusses the skin friction, heat and mass transfer rates defined at the surface of the sphere. The graphs of numerical results are plotted, which reveal that the flow velocity is increased, while the fluid temperature is reduced, for increasing values of the roughness parameter. The presence of mixed convection parameter delays the occurrence of separation in the boundary layer in both the cases of an ordinary fluid and a nanofluid. For increasing values of the Schmidt number, the species concentration decreases, while the rate of mass transfer increases. Moreover, the thermophoresis parameter of the nanofluid increases the fluid's temperature, while it decreases the heat transfer rate. The fluid's temperature reduces for larger values of nonlinear convection parameter. Also, the flow velocity increases for the diffusion of liquid hydrogen.

Mixed convection nanofluid flow in a non-Darcy porous medium with variable permeability: entropy generation analysis

The study discusses the issue of entropy generated in a mixed convection Cu–water nanofluid flow in an inclined channel filled with a non-Darcy porous medium with variable permeability taking into account the Navier slip and convection at the boundary. The equations of momentum and temperature are highly nonlinear and coupled, and these are solved using the homotopy analysis method after converting to the dimensionless form. The flow velocity and temperature expressions as required during the entropy generation analysis are obtained. Bejan number is also obtained which indicates the role of heat transfer and viscous dissipation in the entropy generation process. The consequences of the relevant flow parameters are discussed, and the results are shown graphically. It was observed that entropy is minimum just above the center of the channel width.

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.

A comparative study of γAl2O3–C2H6O2 and γAl2O3–H2O near a vertical curved surface having porous medium

The present analysis reveals the impact of porous medium and mixed convection nano-fluid flow near an exponentially curved surface. For this purpose alumina is treated as nano-particles along with two base fluids such as H2O and C2H6O2. Under different assumptions the mathematical model of energy and momentum equations are developed by using curvilinear coordinates. The PDEs are transformed into non-linear differential equations by using similarity transformation variables. The table of skin friction and Nusselt number are drawn by fluctuating the values of different parameters for both fluids. Moreover, the numerical solutions are generated in MATLAB by using Bvp4c. Influence of effective and without effective Pr numbers for an incompressible γAl2O3−C2H6O2 and γAl2O3−H2O are investigated. We observe that the velocity profile increases for increasing values of curvature, mixed convection and volume fraction of nanoparticles for two different cases effective and with-out effective Prandtl numbers. Moreover, in case of effective Pr number, the temperature profile decreases but for with-out effective Pr number temperature profile increases. Furthermore, the graphs are drawn to check the behavior various parameters for effective and with-out effective Pr numbers.

MHD boundary layer heat and mass transfer flow of nanofluid through porous media over inclined plate with chemical reaction

PurposeSteady-state mixed convection boundary layer flow, heat and mass transfer characteristics of Buongiorno's model nanofluid over an inclined porous vertical plate with thermal radiation and chemical reaction are presented in this analysis.Design/methodology/approachThe governing nonlinear partial differential equations represent the flow model that can be converted into system of nonlinear ordinary differential equations using the similarity variables and are solved numerically using finite element method.FindingsThe rates of nondimensional temperature and concentration are both decelerate with the higher values of thermophoresis parameter (Nt).Originality/valueThe work carried out in this paper is original.

Numerical spectral examination of EMHD mixed convective flow of second-grade nanofluid towards a vertical Riga plate using an advanced version of the revised Buongiorno’s nanofluid model

Present communication aims to determine the impact of Cattaneo–Christov model and convective boundary on second-grade nanofluid flow alongside a Riga pattern. Zero mass flux is accounted at the solid surface of Riga pattern such that the fraction of nanoparticles maintains itself on strong retardation. The impact of Lorentz forces generated by Riga pate is also an important aspect of the study. The governing nonlinear problem is converted into ordinary problems via suitably adjusted transformations. Spectral local linearization method has been incorporated to find the solutions of the nonlinear problems. Variation in horizontal movement of the nanofluid, thermal distribution and concentration distribution of the nanoparticles has been noted for various fluid parameters. The results are plotted graphically. Outcomes indicate that the horizontal movement gains enhancement for elevated values of modified Hartman factor. Thermal state of the nanofluid and concentration of nanoparticles receive reduction for incremental values of relaxation time parameters. Numerical results for skin friction and heat flux have been reported in tabular form. The CPU run time and residual error are obtained to check the efficiency of the method used for finding the solution.

Role of Rotating Cylinder toward Mixed Convection inside a Wavy Heated Cavity via Two-Phase Nanofluid Concept.

The mixed convection two-phase flow and heat transfer of nanofluids were addressed within a wavy wall enclosure containing a solid rotating cylinder. The annulus area between the cylinder and the enclosure was filled with water-alumina nanofluid. Buongiorno’s model was applied to assess the local distribution of nanoparticles in the host fluid. The governing equations for the mass conservation of nanofluid, nanoparticles, and energy conservation in the nanofluid and the rotating cylinder were carried out and converted to a non-dimensional pattern. The finite element technique was utilized for solving the equations numerically. The influence of the undulations, Richardson number, the volume fraction of nanoparticles, rotation direction, and the size of the rotating cylinder were examined on the streamlines, heat transfer rate, and the distribution of nanoparticles. The Brownian motion and thermophoresis forces induced a notable distribution of nanoparticles in the enclosure. The best heat transfer rate was observed for 3% volume fraction of alumina nanoparticles. The optimum number of undulations for the best heat transfer rate depends on the rotation direction of the cylinder. In the case of counterclockwise rotation of the cylinder, a single undulation leads to the best heat transfer rate for nanoparticles volume fraction about 3%. The increase of undulations number traps more nanoparticles near the wavy surface.

Entropy analysis and unsteady MHD mixed convection stagnation-point flow of Casson nanofluid around a rotating sphere

The current perusal introduces a numerical analysis to point out the flow of MHD conjugate forced and free convection with entropy generation analysis due to non-Newtonian Cassonnanofluid around a rotating sphere with convective boundary conditions. Two-phase flow of nanofluid model is employed for the problem under consideration. Both the velocity of free stream and the sphere rotates with angular velocity changed continuously with time. The highly nonlinear partial differential Structures which describe the case study are mutated into a nonlinear ordinary differential structures via utilizing appropriate dimensionless quantities. The numerical solutions of ordinary differential structures have been acquired by applying the fourth order Runge-Kutta-Fehlberg technique with shooting scheme via MATLAB. Aspects of such controlled physical parameters have been clarified and discussed in details using some charts and tables. Comparison with previous literature results is also done and is found to be very good agreement with those published earlier.