MHD Mixed Convection Heat Research Articles

The influence of thermophoretic particle deposition on fully developed MHD mixed convective flow in a vertical channel with thermal-diffusion and diffusion-thermo effects

The present paper deals with the influence of thermophoretic particle deposition on the MHD mixed convective heat and mass transfer flow in a vertical channel in the presence of radiative heat flux with thermal-diffusion and diffusion-thermo effects. The resulting nonlinear coupled equations are solved under appropriate boundary conditions using the homotopy analysis method. The influence of involved parameters on heat and mass transfer characteristics of the fluid flow is presented graphically. It is noted that fluid velocity is an increasing function of radiation parameter, Dufour number, Buoyancy ratio parameter and mixed convection parameter whereas the magnetic parameter, thermophoresis constant, Soret number and Schimidt number lead to suppress the velocity. The fluid temperature increases with increasing radiation parameter and Dufour number. The convergence of homotopy analysis method (HAM) solutions is discussed and a good agreement is found between the analytical and the numerical solution.

Influence of chemical reaction and viscous dissipation on MHD mixed convection flow

This paper investigates the effect of chemical reaction and viscous dissipation on MHD mixed convective heat and mass transfer flow of a viscous, incompressible, electrically conducting second grade fluid past a semi-infinite stretching sheet in the presence of thermal diffusion and thermal radiation with Rosseland approximation. The governing boundary layer equations are written into a dimensionless form by similarity transformations. Numerical results for the dimensionless velocity, temperature, concentration profiles as well as for the skin friction coefficient, Nusselt number and Sherwood number are obtained and displayed through graphs and tables for pertinent parameters to show interesting aspects of the solution.

MHD Effects on Mixed Convection Flow Through a Diverging Channel with Circular Obstacle

MHD mixed convection steady laminar heat and mass transfer flow through an open diverging channel with a circular obstacle is studied numerically in the present work. A circular obstacle is placed at the centre of the channel and the right wall of the channel is heated with temperature Th The top and bottom walls are adiabatic. Using a set of appropriate transformations, the governing equations along with the initial and boundary conditions are transformed into non-dimensional form, which are then solved by employing Galerkin weighted residuals finite element scheme. MHD mixed convection fluid flow and heat transfer within the channel is governed by the inertia force, magnetic intensity and viscosity variation parameter namely Reynolds number (Re), Hartman number (Ha) and Prandtl number (Pr). The computation is carried out for a wide range of Hartmann number Ha, Prandtl number Pr and Reynolds number Re. The obtained results are presented in the form of streamlines, isotherms, average Nusselt number and average temperature of the fluid for various relevant dimensionless groups.

Mixed Convective Heat Transfer for MHD Viscoelastic Fluid Flow over a Porous Wedge with Thermal Radiation

The main concern of the present paper is to study the MHD mixed convective heat transfer for an incompressible, laminar, and electrically conducting viscoelastic fluid flow past a permeable wedge with thermal radiation via a semianalytical/numerical method, called Homotopy Analysis Method (HAM). The boundary-layer governing partial differential equations (PDEs) are transformed into highly nonlinear coupled ordinary differential equations (ODEs) consisting of the momentum and energy equations using similarity solution. The current HAM solution demonstrates very good agreement with previously published studies for some special cases. The effects of different physical flow parameters such as wedge angle (β), magnetic field ( M), viscoelastic ( k1), suction/injection ( fw), thermal radiation ( Nr), and Prandtl number (Pr) on the fluid velocity component ( f′( η)) and temperature distribution ( θ( η)) are illustrated graphically and discussed in detail.

The MHD Mixed Convection Stagnation Point Flow and Heat Transfer in a Porous Medium

The steady two dimensional laminar MHD mixed convection stagnation point flow and heat transfer past a heated semi-infinite permeable surface embedded in a porous medium have been discussed using the mixed convection effects on the flow. The results are obtained by solving the coupled nonlinear partial differential equations describing the conservation of mass, momentum and energy by a perturbation technique. The present study concludes that when local Grashof number and Reynolds number are of the same order, instability in the flow and heat transfer phenomena occur. Further, the fluid with low thermal diffusivity gives rise to constant velocity and temperature gradients.

Combined Effects of Thermophoresis and Chemical Reaction on Magnetohydrodynamics Mixed Convection Flow

The steady two-dimensional MHD mixed convective heat and mass transfer flow of a viscous incompressible electrically conducting second grade fluid past a semi-infinite stretching sheet in the presence of thermal radiation with chemical reaction and thermophoresis is analyzed numerically. Similarity solutions for the transformed governing equations are obtained and the reduced equations are then solved numerically using symbolic software MATHEMATICA. Favorable comparison with previously published work is performed. The features of the flow, heat, and mass transfer characteristics for different values of the material parameters are analyzed and discussed.

MHD mixed convective heat and mass transfer in a viscoelastic fluid in a porous medium towards a stretching sheet with viscous‐Ohmic heating and chemical reaction

AbstractA numerical model is developed to analyse the combined effects of mixed convection magnetohydrodynamic heat and mass transfer in a viscoelastic fluid in a porous medium with chemical reaction, non‐uniform heat source/sink and viscous‐Ohmic dissipation. The governing boundary layer equations for momentum, energy and species transfer are transformed to a set of nonlinear ordinary differential equations by using similarity solutions which are then solved numerically. The effects of magnetic field on local skin‐friction, local Nusselt number and local Sherwood number are studied for various physical parameters. The results show that there are significant effects of various physical parameters on velocity profiles, temperature and concentration profiles.

RETRACTED ARTICLE: Influence of thermophoresis particle deposition and chemical reaction on unsteady non-Darcy MHD mixed convective flow over a porous wedge in the presence of temperature-dependent viscosity

An analysis is presented to investigate the effect of thermophoresis particle deposition and temperature dependent viscosity on unsteady non-Darcy MHD mixed convective heat and mass transfer of a viscous, incompressible and electrically conducting fluid past a porous wedge in the presence of chemical reaction. The wall of the wedge is embedded in a uniform non-Darcian porous medium in order to allow for possible fluid wall suction or injection. The results are compared with those known from the literature and excellent agreement between the results is obtained. The governing partial differential equations of the problem, subjected to their boundary conditions, are solved numerically by applying an efficient solution scheme for local nonsimilarity boundary layer analysis. Numerical calculations are carried out for different values of dimensionless parameter in the problem and an analysis of the results obtained show that the flow field is influenced appreciably by the applied magnetic field and thermophoresis particle deposition.

Effect of thermophoresis particle deposition and chemical reaction on unsteady MHD mixed convective flow over a porous wedge in the presence of temperature-dependent viscosity

An analysis is presented to investigate the effect of thermophoresis particle deposition and temperature dependent viscosity on unsteady MHD mixed convective heat and mass transfer of a viscous, incompressible and electrically conducting fluid past a porous wedge in the presence of chemical reaction. The wall of the wedge is embedded in a uniform non-Darcian porous medium in order to allow for possible fluid wall suction or injection. The results are compared with those known from the literature and excellent agreement between the results is obtained. The governing partial differential equations of the problem, subjected to their boundary conditions, are solved numerically by applying an efficient solution scheme for local nonsimilarity boundary layer analysis. Numerical calculations are carried out for different values of dimensionless parameter in the problem and an analysis of the results obtained show that the flow field is influenced appreciably by the applied magnetic field and thermophoresis particle deposition.

Soret and dufour effects on MHD mixed convection heat and mass transfer in a micropolar fluid

AbstractThis paper analyzes the flow, heat and mass transfer characteristics of the mixed convection on a vertical plate in a micropolar fluid in the presence of Soret and Dufour effects. A uniform magnetic field of magnitude is applied normal to the plate. The governing nonlinear partial differential equations are transformed into a system of coupled nonlinear ordinary differential equations using similarity transformations and then solved numerically using the Keller-box method. The numerical results are compared and found to be in good agreement with previously published results as special cases of the present investigation. The rate of heat and mass transfer at the plate are presented graphically for various values of coupling number, magnetic parameter, Prandtl number, Schmidt number, Dufour and Soret numbers. In addition, the skin-friction coefficient, the wall couple stress are shown in a tabular form.

Perturbation technique for unsteady MHD mixed convection periodic flow, heat and mass transfer in micropolar fluid with chemical reaction in the presence of thermal radiation

Abstract An analytical study is presented for the problem of unsteady hydromagnetic heat and mass transfer for a micropolar fluid bounded by semi-infinite vertical permeable plate in the presence of first-order chemical reaction, thermal radiation and heat absorption. A uniform magnetic field acts perpendicularly to the porous surface which absorbs the micropolar fluid with a time-dependent suction velocity. The basic partial differential equations are reduced to a system of nonlinear ordinary differential equations which are solved analytically using perturbation technique. Numerical calculations for the analytical expressions are carried out and the results are shown graphically. The effects of the various dimensionless parameters related to the problem on the velocity, angular velocity, temperature and concentration fields are discussed in detail.

MHD mixed convective heat transfer over a permeable stretching wedge with thermal radiation and ohmic heating

In this paper, a new analytical method named DTM-BF is proposed and applied to study the MHD mixed convective flow and heat transfer of an incompressible, viscous and electrically conducting fluid over a stretching permeable wedge in the presence of thermal radiation and ohmic heating. The boundary layer governing equations of PDES are transformed into highly nonlinear coupled ODES and the approximate solutions are derived by the new proposed analytical technique—the differential transformation and basis functions method (DTM-BF) on unbounded domains. The effects of the velocity ratio parameter, magnetic field parameter, the wedge angle parameter, the mixed convection parameter, suction/injection parameter, thermal radiation parameter, Eckert number and Prandtl number are presented. Moreover, the reliability and effectiveness of the DTM-BF have been verified by comparing analytical results with numerical solutions. Some new characteristics of the mixed convective flow and heat transfer over a wedge are investigated and discussed.

Effects of thermophoresis and thermal radiation on MHD mixed convective heat and mass transfer flow

An analysis is presented to investigate the combined effects of thermophoresis and thermal radiation on MHD mixed convective heat and mass transfer flow of an incompressible, electrically conducting second grade fluid past a semi-infinite stretching sheet in the presence of viscous dissipation and Joule heating. The governing boundary layer equations are written into a dimensionless form by similarity transformations. The transformed non-linear ordinary differential equations are solved numerically using symbolic software MATHEMATICA. Favorable comparison with previously published work is performed. Numerical results for dimensionless velocity, temperature, concentration as well as the skin friction coefficient, Nusselt number and Sherwood number are presented through graphs and tables for pertinent parameters to show interesting aspects of the solution.

Combined effects of chemical reaction and temperature dependent heat source on MHD mixed convective flow of a couple-stress fluid in a vertical wavy porous space with travelling thermal waves

A mathematical model is developed to examine the effect of chemical reaction on MHD mixed convective heat and mass transfer flow of a couple-stress fluid in vertical porous space in the presence of temperature dependent heat source with travelling thermal waves. The dimensionless governing equations are assumed to be made up of two parts: a mean part corresponding to the fully developed mean flow, and a small perturbed part, using amplitude as a small parameter. The analytical solution of perturbed part have been carried out by using the long-wave approximation. The expressions for the zeroth-order and the first order solutions are obtained and the results of the heat and mass transfer characteristics are presented graphically for various values of parameters entering into the problem. It is noted that velocity of the fluid increases with the increase of the couple stress parameter and increasing the chemical reaction parameter leads suppress the velocity of the fluid. Cross velocity decreases with an increase of the phase angle. The increase of the chemical reaction parameter and Schmidt number lead to decrease the fluid concentration. The hydrodynamic case for a non-porous space in the absence of the temperature dependent heat source for Newtonian fluid can be captured as a limiting case of our analysis by taking, and ?1?0, Da??, a??.

Magnetohydrodynamic laminar boundary-layer flow over a porous wedge with thermophoresis particle deposition in the presence of variable stream conditions

An analysis is presented to investigate the effects of thermophoresis variable viscosity on MHD mixed convective heat and mass transfer of a viscous, incompressible and electrically conducting fluid past a porous wedge in the presence of chemical reaction. The wall of the wedge is embedded in a uniform porous medium in order to allow for possible fluid wall suction or injection. The governing boundary layer equations are written into a dimensionless form by local non-similarity transformations. The transformed coupled nonlinear ordinary differential equations are solved numerically by using the R.K. Gill and shooting methods. Favorable comparison with previously published work is performed. Numerical results for the dimensionless velocity, temperature and concentration profiles are obtained and displayed graphically for pertinent parameters to show interesting aspects of the solution.

Homotopy analysis method for chemical reaction and thermophoresis effects on heat and mass transfer for mhd hiemenz flow over a porous wedge in the presence of heat radiation

An analytical technique, namely, the homotopy analysis method, is applied to analyze the effect of chemical reaction and thermophoresis particle deposition on the MHD mixed convective heat and mass transfer for a Hiemenz flow over a porous wedge in the presence of heat radiation. The fluid is assumed to be viscous and incompressible. Analytical and numerical calculations are carried out for different values of dimensionless parameters, and an analysis of the results obtained shows that the flow field is influenced appreciably by the buoyancy ratio as well as by the thermal diffusion and suction/injection parameters. The effects of these parameters on the process characteristics are investigated methodically, and typical results are illustrated. An explicit, totally analytical, and uniformly valid solution is derived which agrees well with numerical results.

Effects of chemical reaction and space porosity on MHD mixed convective flow in a vertical asymmetric channel with peristalsis

This work is aimed at describing MHD mixed convective heat and mass transfer peristaltic flow through a vertical porous space in the presence of a chemical reaction. The flow is examined in a wave frame of reference moving with the velocity of the wave. The channel asymmetry is produced by choosing the peristaltic wave train on the walls to have different amplitude and phase. The momentum, energy and concentration equation have been linearized under long-wavelength approximation. Expressions for dimensionless stream function, temperature and concentration field are constructed. The features of the fluid flow, heat and mass transfer characteristics are analyzed by plotting graphs and discussed in detail.

Local non-similarity solution to impact of chemical reaction on MHD mixed convection heat and mass transfer flow over porous wedge in the presence of suction / injection

Combined heat and mass transfer on free, forced, and mixed convection flow along a porous wedge with magnetic effect in the presence of chemical reaction is investigated. The flow field characteristics are analyzed by the Runge-Kutta-Gill scheme with the shooting method as well as the local non-similarity method up to the third level of truncation, which are used to reduce the governing partial differential equations into nine ordinary differential equations. The governing boundary layer equations are converted to a dimensionless form by Falkner-Skan transformations. Because of the effect of suction/injection on the wall of the wedge with buoyancy force and variable wall temperature, the flow field is locally non-similar. Numerical calculations up to the third order level of truncation are carried out as a special case for different values of dimensionless parameters. Effects of the magnetic field strength in the presence of chemical reaction with variable wall temperature and concentration on the dimensionless velocity, temperature and concentration profiles are shown graphically.

Local Nonsimilarity Solution for the Impact of a Chemical Reaction in an MHD Mixed Convection Heat and Mass Transfer Flow over a Porous Wedge in the Presence Of Suction/Injection

Combined heat and mass transfer in free, forced, and mixed convection flows along a porous wedge with a magnetic effect in the presence of a chemical reaction is investigated. The flow field characteristics are analyzed with the Runge—Kutta—Gill method in conjunction with the shooting method, and local nonsimilarity method. The governing boundary-layer equations are written in a dimensionless form with the use of the Falkner—Skan transformations. Owing to the effect of the buoyancy force, the power law of temperature and concentration, and suction/injection on the wall of the wedge, the flow field is locally nonsimilar. Numerical calculations up to the third-order level of truncation are carried out for different values of dimensionless parameters as a special case. Effects of the magnetic field strength in the presence of a chemical reaction with a variable wall temperature and concentration on the dimensionless velocity, temperature, and concentration profiles are shown graphically. Comparisons with previously published works are performed, and excellent agreement between the results is obtained.

Thermophoresis effects on non-Darcy MHD mixed convective heat and mass transfer past a porous wedge in the presence of suction/injection

An analysis is presented to investigate the effect of thermophoresis particle deposition and variable viscosity on non-Darcy MHD mixed convective heat and mass transfer of a viscous, incompressible and electrically conducting fluid past a porous wedge in the presence of suction/injection. The wall of the wedge is embedded in a uniform non-Darcian porous medium in order to allow for possible fluid wall suction or injection. The governing partial differential equations of the problem, subjected to their boundary conditions, are solved numerically by applying an efficient solution scheme for local nonsimilarity boundary layer analysis. Numerical calculations are carried out for different values of dimensionless parameter in the problem and an analysis of the results obtained show that the flow field is influenced appreciably by the applied magnetic field. The results are compared with those known from the literature and excellent agreement between the results is obtained.