Effects of Dufour and thermal diffusion on unsteady MHD free convection and mass transfer flow through an infinite vertical permeable sheet

AbstractIn this paper, the effects of Dufour and thermal diffusion and on unsteady MHD (magnetohydrodynamic) free convection and mass transfer flow through an infinite vertical permeable sheet have been investigated numerically. The non-dimensional governing equations are solved numerically by using the superposition method with the help of “Tec plot” software. The numerical solution regarding the non-dimensional velocity, temperature, and concentration variables against the non-dimensional coordinate variable has been carried out for various values of pertinent numbers and parameters like the suction parameter $$\left( {v_{0} } \right)$$ v 0 , Prandtl number $$\left( {P_{r} } \right)$$ P r , magnetic parameter $$\left( M \right)$$ M , Dufour number $$\left( {D_{f} } \right)$$ D f , Soret number $$\left( {S_{0} } \right)$$ S 0 , Schmidt number $$\left( {S_{c} } \right)$$ S c , and for constant values of modified local Grashof number $$\left( {G_{{\text{m}}} } \right)$$ G m and local Grashof number $$\left( {G_{r} } \right)$$ G r .The velocity field decreases for increasing the suction parameter which is focusing on the common fact that the usual suction parameter stabilizing the effect on the boundary layer growth. The thermal boundary layer thickness becomes thinner for rising values of the Dufour and Soret numbers. The skin friction enhances for uplifting values of Soret number and Dufour number but reduces for moving suction parameter, Magnetic force number, Prandtl number, and Schmidt number. The heat transfer rate increases for increasing the suction parameter, Dufour number, Prandtl number, and Soret number. The mass transfer rate increases for enhancing the values of suction parameter, Magnetic force number, Soret number, and Prandtl number but decreases for Dufour number and Schmidt number.

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Distribution of Mass Transfer Rate and Wall Shear Stress Behind Simple Rectangular Stenosis in Pulsating Flow

Journal of Biomechanical Engineering ◽

10.1115/1.3168339 ◽

1989 ◽

Vol 111 (1) ◽

pp. 47-54 ◽

Cited By ~ 9

Author(s):

R. Yamaguchi

Keyword(s):

Mass Transfer ◽

Shear Stress ◽

Wall Shear Stress ◽

Transfer Rate ◽

Schmidt Number ◽

Fluid Dynamic ◽

Mass Transfer Rate ◽

Pulsating Flow ◽

Flow Through ◽

Wall Shear

The distributions of mass transfer rate and wall shear stress in sinusoidal laminar pulsating flow through a two-dimensional asymmetric stenosed channel have been studied experimentally and numerically. The distributions are measured by the electrochemical method. The measurement is conducted at a Reynolds number of about 150, a Schmidt number of about 1000, a nondimensional pulsating frequency of 3.40, and a nondimensional flow amplitude of 0.3. It is suggested that the deterioration of an arterial wall distal to stenosis may be greatly enhanced by fluid dynamic effects.

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Transient Heat and Mass Transfer Flow through Salt Water in an Ocean by Inclined Angle

Technological Engineering ◽

10.2478/teen-2016-0017 ◽

2016 ◽

Vol 13 (2) ◽

pp. 21-27

Author(s):

lfsana Karim ◽

M.S. Khan ◽

M.M. Alam ◽

M.A. Rouf ◽

M. Ferdows ◽

...

Keyword(s):

Mass Transfer ◽

Finite Difference ◽

Prandtl Number ◽

Heat And Mass Transfer ◽

Water Flow ◽

Salt Water ◽

Governing Equations ◽

Flow Through ◽

Inclined Angle ◽

Transfer Flow

Abstract In the present computational study, the inclined angle effect of unsteady heat and mass transfer flow through salt water in an ocean was studied. The governing equations together with continuity, momentum, salinity and temperature were developed using the boundary layer approximation. Cartesian coordinate system was introduced to interpret the physical model where x-axis chosen along the direction of salt water flow and y-axis is inclined to x-axis. Two angle of inclination was considered such as 90° and 120°. The time dependent governing equations under the initial and boundary conditions were than transformed into the dimensionless form. A numerical solution approach so-called explicit finite difference method (EFDM) was employed to solve the obtained dimensionless equations. Different physical parameter was found in the model such as Prandtl number, Modified Prandtl number, Grashof number, Heat source parameter and Soret number. A stability and convergence analysis was developed in this study to describe the aspects of the finite difference scheme and this analysis is significant due to accuracy of the EFDM approach. The convergence criteria were observed to be in terms of dimensionless parameter as Pr ≥ 0.0128 and Ps ≥ 0.016. The distributions of the temperature and salinity profiles of salt water flow over different time steps were investigated for the effect of different dimensionless parameters and shown graphically.

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Transient natural convention heat and mass transfer flow in a vertical channel in the presence of Soret and Dufour effects: An analytical approach

International Journal of Modern Physics C ◽

10.1142/s0129183120500321 ◽

2020 ◽

Vol 31 (02) ◽

pp. 2050032

Author(s):

Basant K. Jha ◽

Yusuf Y. Gambo

Keyword(s):

Mass Transfer ◽

Heat And Mass Transfer ◽

Vertical Channel ◽

Soret And Dufour Effects ◽

Velocity Increase ◽

Grashof Number ◽

Increase With Increase ◽

Soret Number ◽

Dufour Number ◽

Transfer Flow

This paper presents an analytical solution for transient natural convection heat and mass transfer flow in a vertical channel with Soret and Dufour effects. Due to the presence of these two effects, energy and concentration equations are coupled. The dimensionless governing equations for momentum, energy and concentration are first decoupled using perturbation method and then solved using Laplace Transform Technique (LTT) under relevant initial and boundary conditions. The expressions for temperature, concentration, velocity, rate of heat transfer, rate of mass transfer and skin-friction are obtained. Numerical solutions are also obtained using pdepe in MATLAB so as to validate the accuracy of the proposed analytical method. The effects of Soret parameter, Dufour parameter, Grashof number, modified Grashof number, Prandtl number, Schmidt number and dimensionless time are presented graphically and discussed. It is observed that the temperature and velocity increase with increase in Dufour number, while concentration decreases with increase of Dufour number. The Dufour effect is more significant on the temperature and velocity in comparison to concentration. Moreover, it is observed that the concentration and velocity increase with increase in Soret number while the impact of Soret number is just contrast on temperature variation.

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Study of MHD Heat and Mass Transfer Flow for Hall and Ion-Slip Currents Effects in High Porosity Medium and Revolving System

Academic Journal of Applied Mathematical Sciences ◽

10.32861/ajams.67.100.125 ◽

2020 ◽

pp. 100-125

Author(s):

Md. Delowar Hossain ◽

Md. Abdus Samad ◽

Md. Mahmud Alam

Keyword(s):

Mass Transfer ◽

Prandtl Number ◽

Heat And Mass Transfer ◽

Magnetic Parameter ◽

Physical Parameters ◽

Concentration Profiles ◽

High Porosity ◽

Ion Slip ◽

Soret Number ◽

Transfer Flow

In high porosity medium and revolving system the effects of ion-slip and Hall currents are studied on MHD heat and mass transfer flow. The non-linear coupled partial differential equations are determined using byl transformations and solve these equations employing finite difference method. Velocity, temperature as well as concentration profiles are studied for the concerned physical parameters and results are presented graphically. Due to the Hall and ion-slip parameters, Eckert number, and porosity parameter the velocity profiles are pronounced while it is declined for the effects of magnetic parameter, Prandtl number. Also the magnetic parameter enhances the temperature profiles. On the other hand, the temperature (concentration) profile decreases (increases) for the increasing effect of Prandtl number (Soret number). The rate of changes of velocity, temperature and concentration profiles are also presented graphically.

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Thermo-Diffusion and Diffusion-Thermo Effects on MHD Free Convective Heat and Mass Transfer from a Sphere Embedded in a Non-Darcian Porous Medium

Journal of Thermodynamics ◽

10.1155/2012/725142 ◽

2012 ◽

Vol 2012 ◽

pp. 1-17 ◽

Cited By ~ 5

Author(s):

B. Vasu ◽

V. R. Prasad ◽

O. Anwar Bég

Keyword(s):

Mass Transfer ◽

Porous Medium ◽

Heat And Mass Transfer ◽

Concentration Function ◽

Suction Parameter ◽

Soret Number ◽

Implicit Finite Difference ◽

Dufour Number ◽

And Diffusion ◽

Well Posed

The problem of combined heat and mass transfer by natural convection over a sphere in a homogenous non-Darcian porous medium subjected to uniform magnetic field is numerically studied, taking Soret/Dufour effects into account. The coupled, steady, and laminar partial differential conservation equations of mass, momentum, energy, and species diffusion are normalized with appropriate transformations. The resulting well-posed two-point boundary value problem is solved using the well-tested, extensively validated Keller-Box implicit finite difference method, with physically realistic boundary conditions. A parametric study of the influence of Soret number (Sr), Dufour number (Du), Forchheimer parameter (Λ), Darcy parameter (Da), buoyancy ratio parameter (), Prandtl number (Pr), Schmidt number (Sc), magnetohydrodynamic body force parameter (), wall transpiration () is the blowing/suction parameter, and streamwise variable (ξ) on velocity, temperature, and concentration function evolution in the boundary layer regime is presented. Shear stress, Nusselt number, and Sherwood number distributions are also computed. Applications of the study arise in hydromagnetic flow control of conducting transport in packed beds, magnetic materials processing, geophysical energy systems, and magnetohydrodynamic chromatography technology.

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Numerical Study of the Combined Free-Forced Convection and Mass Transfer Flow Past a Vertical Porous Plate in a Porous Medium with Heat Generation and Thermal Diffusion

Nonlinear Analysis Modelling and Control ◽

10.15388/na.2006.11.4.14737 ◽

2006 ◽

Vol 11 (4) ◽

pp. 331-343 ◽

Cited By ~ 19

Author(s):

M. S. Alam ◽

M. M. Rahman ◽

M. A. Samad

Keyword(s):

Mass Transfer ◽

Flow Field ◽

Differential Equations ◽

Forced Convection ◽

Heat Generation ◽

Numerical Study ◽

Porous Plate ◽

Integration Scheme ◽

Suction Parameter ◽

Transfer Flow

The problem of combined free-forced convection and mass transfer flow over a vertical porous flat plate, in presence of heat generation and thermaldiffusion, is studied numerically. The non-linear partial differential equations and their boundary conditions, describing the problem under consideration, are transformed into a system of ordinary differential equations by using usual similarity transformations. This system is solved numerically by applying Nachtsheim-Swigert shooting iteration technique together with Runge-Kutta sixth order integration scheme. The effects of suction parameter, heat generation parameter and Soret number are examined on the flow field of a hydrogen-air mixture as a non-chemical reacting fluid pair. The analysis of the obtained results showed that the flow field is significantly influenced by these parameters.

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Free Convection and Mass Transfer Flow Near a Moving Vertical Porous Plate: An Analytical Solution

Journal of Applied Mechanics ◽

10.1115/1.2745411 ◽

2008 ◽

Vol 75 (1) ◽

Cited By ~ 9

Author(s):

C. J. Toki

Keyword(s):

Mass Transfer ◽

Analytical Solution ◽

Free Convection ◽

Schmidt Number ◽

Porous Plate ◽

Grashof Number ◽

Vertical Porous Plate ◽

Laplace Transform Technique ◽

The Laplace Transform ◽

Transfer Flow

An exact solution of the problem of the unsteady free convection and mass transfer flow near an infinite vertical porous plate, which moves with time-dependent velocity in a viscous and incompressible fluid, is presented here by the Laplace transform technique. All expressions of the new solutions of the present problem were obtained in closed forms with arbitrary Prandtl number (Pr), Schmidt number (Sc), thermal Grashof number (Gr), and mass Grashof number (Gm). Two applications of physical interest for porous or nonporous plate are discussed. Applying numerical values into the expressions of analytical solution, we was also discussed the vertical air flows—the usual phenomenon at plumes into the atmosphere.

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