Exact Solutions for the Magnetohydrodynamic Flow of a Jeffrey Fluid with Convective Boundary Conditions and Chemical Reaction

2012 ◽  
Vol 67 (8-9) ◽  
pp. 517-524 ◽  
Author(s):  
Ahmed Alsaedi ◽  
Zahid Iqbal ◽  
Meraj Mustafa ◽  
Tasawar Hayat
Keyword(s):  
Boundary Layer ◽  
Mass Transfer ◽  
Boundary Conditions ◽  
Heat And Mass Transfer ◽  
Chemical Reaction ◽  
Similarity Solutions ◽  
Jeffrey Fluid ◽  
Rheological Parameter ◽  
Convective Boundary Conditions ◽  
Convective Boundary

The two-dimensional magnetohydrodynamic (MHD) flow of a Jeffrey fluid is investigated in this paper. The characteristics of heat and mass transfer with chemical reaction have also been analyzed. Convective boundary conditions have been invoked for the thermal boundary layer problem. Exact similarity solutions for flow, temperature, and concentration are derived. Interpretation to the embedded parameters is assigned through graphical results for dimensionless velocity, temperature, concentration, skin friction coefficient, and surface heat and mass transfer. The results indicate an increase in the velocity and the boundary layer thickness by increasing the rheological parameter of the Jeffrey fluid. An intensification in the chemical reaction leads to a thinner concentration boundary layer.

scholarly journals Heat and Mass Transfer in Unsteady Boundary Layer Flow of Williamson Nanofluids

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Tesfaye Kebede ◽  
Eshetu Haile ◽  
Gurju Awgichew ◽  
Tadesse Walelign
Keyword(s):  
Magnetic Field ◽  
Boundary Layer ◽  
Mass Transfer ◽  
Differential Equations ◽  
Boundary Conditions ◽  
Thermal Radiation ◽  
Heat And Mass Transfer ◽  
Chemical Reaction ◽  
Stretching Sheet ◽  
Analytic Approximation

In this paper, analytic approximation to the heat and mass transfer characteristics of a two-dimensional time-dependent flow of Williamson nanofluids over a permeable stretching sheet embedded in a porous medium has been presented by considering the effects of magnetic field, thermal radiation, and chemical reaction. The governing partial differential equations along with the boundary conditions were reduced to dimensionless forms by using suitable similarity transformation. The resulting system of ordinary differential equations with the corresponding boundary conditions was solved via the homotopy analysis method. The results of the study show that velocity, temperature, and concentration boundary layer thicknesses generally decrease as we move away from the surface of the stretching sheet and the Williamson parameter was found to retard the velocity but it enhances the temperature and concentration profiles near the surface. It was also found that increasing magnetic field strength, thermal radiation, or rate of chemical reaction speeds up the mass transfer but slows down the heat transfer rates in the boundary layer. The results of this study were compared with some previously published works under some restrictions, and they are found in excellent agreement.

scholarly journals Nanofluid Flow over a Permeable Surface with Convective Boundary Conditions and Radiative Heat Transfer

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
P. K. Kameswaran ◽  
P. Sibanda ◽  
A. S. N. Murti
Keyword(s):  
Mass Transfer ◽  
Boundary Conditions ◽  
Heat And Mass Transfer ◽  
Volume Fraction ◽  
Solute Concentration ◽  
Skin Friction Coefficient ◽  
Convective Boundary Conditions ◽  
Nanofluid Flow ◽  
Convective Boundary ◽  
Transfer Rates

We investigate the effects of thermal radiation and convective boundary conditions on heat and mass transfer in nanofluid flow over a permeable flat plate. The mathematical model for the nanofluid incorporates variations in the nanoparticle volume fraction of up to 20%. The performance of two water-based nanofluids, namely, stable suspensions of copper and gold nanoparticles in water was investigated. The governing partial differential equations were transformed into ordinary ones using a similarity transformation and solved numerically. The numerical results were validated by comparison with previously published results in the literature. The main focus of this paper is to study the fluid and surface parameters such as the radiation parameter, and suction/injection parameter, solute concentration profiles, as well as the skin friction coefficient and heat and mass transfer rates were conducted.

scholarly journals On the Theory of Stable Mode of Dendritic Growth in the Presence of Convective Heat and Mass Transfer Boundary Conditions

2020 ◽  
Vol 15 ◽  
Keyword(s):  
Mass Transfer ◽  
Boundary Conditions ◽  
Heat And Mass Transfer ◽  
Dendritic Growth ◽  
Mass Transfer Process ◽  
Growth Mode ◽  
Conductive Heat ◽  
Convective Boundary Conditions ◽  
Convective Boundary ◽  
Stable Mode

The dendritic form is one of the most common forms of crystals growing from supercooled melts and supersaturated solutions. In recent decades, an analytical theory has been developed that describes a stable dendrite growth mode under the conditions of a conductive heat and mass transfer process. However, in experiments, the growth of dendritic crystals is often observed under the conditions of convective fluid flow. In the present work, the theory of the growth of dendritic crystals is developed taking into account the convective mechanism of heat and mass transfer at the crystal-melt interface. A stable mode of dendritic growth in the case of intense convective flows near the steady-state growing dendritic tip is analyzed. The selection theory determining a stable growth mode in the vicinity of parabolic solutions as well as the undercooling balance condition are used to find the dendrite tip velocity and its tip diameter as functions of the melt undercooling. It is shown that the theoretical predictions in the case of convective boundary conditions are in agreement with experimental data for small undercoolings. In addition, the convective and conductive heat and mass transfer mechanisms near the growing dendritic surfaces are compared. Our calculations show that the convective boundary conditions essentially influence the stable mode of dendritic growth.

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