scholarly journals Diffussion-thermo and chemical reaction effects on an unsteady MHD free convection flow in a micropolar fluid

2016 ◽  
Vol 43 (1) ◽  
pp. 117-131 ◽  
Author(s):  
Siva Sheri ◽  
M.D. Shamshuddin
Keyword(s):  
Boundary Layer ◽  
Chemical Reaction ◽  
Porous Plate ◽  
Skin Friction Coefficient ◽  
Convection Flow ◽  
Local Skin ◽  
Layer Analysis ◽  
Local Skin Friction ◽  
Homogeneous Chemical ◽  
Chemically Reacting

This paper considers a boundary layer analysis on the effects of diffusion-thermo, heat absorption and homogeneous chemical reaction on mag- netohydrodynamic flow of an incompressible, laminar chemically reacting mi- cropolar fluid past a semi-infinite vertical porous plate is made numerically. The governing partial differential equations are solved numerically using the finite element method. The numerical results are compared and found to be in good agreement with previous results as special case of the present inves- tigation. The effects of the various important parameters entering into the problem on the velocity, microrotation, temperature and concentration fields within the boundary layer are discussed and explained graphically. Also the effects of the pertinent parameters on the local Skin friction coefficient, wall Couple stress and rates of heat and mass transfer in terms of the local Nusselt and Sherwood numbers are presented numerically in tabular form.

scholarly journals A Note on Variable Viscosity and Chemical Reaction Effects on Mixed Convection Heat and Mass Transfer Along a Semi-Infinite Vertical Plate

2007 ◽  
Vol 2007 ◽  
pp. 1-7 ◽  
Author(s):  
Mostafa A. A. Mahmoud
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Chemical Reaction ◽  
Variable Viscosity ◽  
Porous Plate ◽  
Skin Friction Coefficient ◽  
Local Skin ◽  
Boundary Layer Equations ◽  
Similarity Transformations ◽  
Local Skin Friction

In the present study, an analysis is carried out to study the variable viscosity and chemical reaction effects on the flow, heat, and mass transfer characteristics in a viscous fluid over a semi-infinite vertical porous plate. The governing boundary layer equations are written into a dimensionless form by similarity transformations. The transformed coupled nonlinear ordinary differential equations are solved numerically by using the shooting method. The effects of different parameters on the dimensionless velocity, temperature, and concentration profiles are shown graphically. In addition, tabulated results for the local skin-friction coefficient, the local Nusselt number, and the local Sherwood number are presented and discussed.

scholarly journals Effects of Slip and Heat Generation/Absorption on MHD Mixed Convection Flow of a Micropolar Fluid over a Heated Stretching Surface

2010 ◽  
Vol 2010 ◽  
pp. 1-20 ◽  
Author(s):  
Mostafa Mahmoud ◽  
Shimaa Waheed
Keyword(s):  
Nusselt Number ◽  
Friction Coefficient ◽  
Mixed Convection ◽  
Skin Friction ◽  
Heat Generation ◽  
Local Nusselt Number ◽  
Skin Friction Coefficient ◽  
Convection Flow ◽  
Local Skin ◽  
Local Skin Friction

A theoretical analysis is performed to study the flow and heat transfer characteristics of magnetohydrodynamic mixed convection flow of a micropolar fluid past a stretching surface with slip velocity at the surface and heat generation (absorption). The transformed equations solved numerically using the Chebyshev spectral method. Numerical results for the velocity, the angular velocity, and the temperature for various values of different parameters are illustrated graphically. Also, the effects of various parameters on the local skin-friction coefficient and the local Nusselt number are given in tabular form and discussed. The results show that the mixed convection parameter has the effect of enhancing both the velocity and the local Nusselt number and suppressing both the local skin-friction coefficient and the temperature. It is found that local skin-friction coefficient increases while the local Nusselt number decreases as the magnetic parameter increases. The results show also that increasing the heat generation parameter leads to a rise in both the velocity and the temperature and a fall in the local skin-friction coefficient and the local Nusselt number. Furthermore, it is shown that the local skin-friction coefficient and the local Nusselt number decrease when the slip parameter increases.

scholarly journals Mixed Convection Flow of Magnetic Viscoelastic Polymer from a Nonisothermal Wedge with Biot Number Effects

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
S. Abdul Gaffar ◽  
V. Ramachandra Prasad ◽  
Bhuvana Vijaya ◽  
O. Anwar Beg
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Mixed Convection ◽  
Biot Number ◽  
Fluid Model ◽  
Numerical Code ◽  
Convection Flow ◽  
Local Skin ◽  
Local Skin Friction ◽  
Layer Flow

Magnetic polymers are finding increasing applications in diverse fields of chemical and mechanical engineering. In this paper, we investigate the nonlinear steady boundary layer flow and heat transfer of such fluids from a nonisothermal wedge. The incompressible Eyring-Powell non-Newtonian fluid model is employed and a magnetohydrodynamic body force is included in the simulation. The transformed conservation equations are solved numerically subject to physically appropriate boundary conditions using a second-order accurate implicit finite difference Keller Box technique. The numerical code is validated with previous studies. The influence of a number of emerging nondimensional parameters, namely, the Eyring-Powell rheological fluid parameter (ε), local non-Newtonian parameter based on length scale (δ), Prandtl number (Pr), Biot number (γ), pressure gradient parameter (m), magnetic parameter (M), mixed convection parameter (λ), and dimensionless tangential coordinate (ξ), on velocity and temperature evolution in the boundary layer regime is examined in detail. Furthermore, the effects of these parameters on surface heat transfer rate and local skin friction are also investigated.

scholarly journals Series Solutions of Boundary Layer Flow of a Micropolar Fluid Near the Stagnation Point Towards a Shrinking Sheet

2009 ◽  
Vol 64 (9-10) ◽  
pp. 575-582 ◽  
Author(s):  
Sohail Nadeem ◽  
Saeid Abbasbandy ◽  
Majid Hussain
Keyword(s):  
Boundary Layer ◽  
Boundary Layer Flow ◽  
Micropolar Fluid ◽  
Skin Friction Coefficient ◽  
Shrinking Sheet ◽  
Local Skin ◽  
Similarity Transformations ◽  
Homotopy Analysis ◽  
Local Skin Friction ◽  
Layer Flow

An analysis has been carried out to obtain the series solution of boundary layer flow of a micropolar fluid towards a shrinking sheet. The governing equations of micropolar fluid are simplified using suitable similarity transformations and then solved by homotopy analysis method (HAM). The convergence of the HAM solutions has been obtained by using homotopy-pade approximation. The effects of various parameters such as porosity parameter R, the ratio λ and the microinertia K on the velocity and microinertia profiles as well as local skin friction coefficient are presented graphically and in tabulated form.

scholarly journals Conjugate Effects of Heat and Mass Transfer on Natural Convection Flow Across an Isothermal Horizontal Circular Cylinder With Chemical Reaction

2007 ◽  
Vol 12 (2) ◽  
pp. 191-201 ◽  
Author(s):  
Md. A. Hye ◽  
Md. M. Molla ◽  
M. A. H. Khan
Keyword(s):  
Boundary Layer ◽  
Natural Convection ◽  
Chemical Reaction ◽  
Transfer Rate ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Species Concentration ◽  
Local Skin ◽  
Boundary Layer Equations ◽  
Wide Range

Natural convection flow across an isothermal cylinder immersed in a viscous incompressible fluid in the presence of species concentration and chemical reaction has been investigated. The governing boundary layer equations are transformed into a system of non-dimensional equations and the resulting nonlinear system of partial differential equations is reduced to a system of local non-similarity boundary layer equations, which is solved numerically by a very efficient implicit finite difference method together with the Keller-box scheme. Numerical results are presented by the velocity, temperature and species concentration profiles of the fluid as well as the local skin-friction coefficient, local heat transfer rate and local species concentration transfer rate for a wide range of chemical reaction parameter γ (γ = 0.0, 0.5, 1.0, 2.0, 4.0), buoyancy ratio parameter N (N = −1.0, −0.5, 0.0, 0.5, 1.0), Schmidt number Sc (Sc = 0.7, 10.0, 50.0, 100.0) andPrandtl number Pr (Pr = 0.7, 7.0).

scholarly journals Radiation and mass transfer effects on an unsteady MHD free convection flow past a heated vertical plate in a porous medium with viscous dissipation

2007 ◽  
Vol 34 (2) ◽  
pp. 135-160 ◽  
Author(s):  
Ramachandra Prasad ◽  
Bhaskar Reddy
Keyword(s):  
Boundary Layer ◽  
Mass Transfer ◽  
Viscous Dissipation ◽  
Porous Plate ◽  
Skin Friction Coefficient ◽  
Convection Flow ◽  
Governing Equations ◽  
Convective Boundary ◽  
Electrically Conducting ◽  
Layer Flow

An unsteady, two-dimensional, hydromagnetic, laminar free convective boundary-layer flow of an incompressible, Newtonian, electrically-conducting and radiating fluid past an infinite heated vertical porous plate with heat and mass transfer is analyzed, by taking into account the effect of viscous dissipation. The dimensionless governing equations for this investigation are solved analytically using two-term harmonic and non-harmonic functions. Numerical evaluation of the analytical results is performed and graphical results for velocity, temperature and concentration profiles within the boundary layer and tabulated results for the skin-friction coefficient, Nusselt number and Sherwood number are presented and discussed. It is observed that, when the radiation parameter increases, the velocity and temperature decrease in the boundary layer, whereas when thermal and solutal Grashof increases the velocity increases.

Stagnation point flow of MHD chemically reacting nanofluid over a stretching convective surface with slip and radiative heat

2016 ◽  
Vol 231 (4) ◽  
pp. 695-703 ◽  
Author(s):  
OD Makinde ◽  
WA Khan ◽  
ZH Khan
Keyword(s):  
Differential Equations ◽  
Stagnation Point ◽  
Fluid Velocity ◽  
Nonlinear Partial Differential Equations ◽  
Stagnation Point Flow ◽  
Partial Slip ◽  
Local Skin ◽  
Local Skin Friction ◽  
Homogeneous Chemical ◽  
Chemically Reacting

This paper investigates the combined effects of buoyancy forces, homogeneous chemical reaction, thermal radiation, partial slip, heat source, Thermophoresis and Brownian motion on hydromagnetic stagnation point flow of nanofluid with heat and mass transfer over a stretching convective surface. The stretching velocity and the ambient fluid velocity are assumed to vary linearly with the distance from the stagnation point. Using similarity transformation, the governing nonlinear partial differential equations are reduced to a set of nonlinear ordinary differential equations which are solved numerically by employing by shooting method coupled with Runge–Kutta Fehlberg integration technique. Graphical results showing the effects of various thermophysical parameters on the velocity, temperature, nanoparticle concentration, local skin friction, local Nusselt number and local Sherwood number are presented and discussed quantitatively.

A numerical investigation of transient MHD free convective flow of a nanofluid over a moving semi-infinite vertical cylinder

2017 ◽  
Vol 34 (5) ◽  
pp. 1393-1412 ◽  
Author(s):  
V. Rajesh ◽  
A.J. Chamkha ◽  
Ch. Sridevi ◽  
A.F. Al-Mudhaf
Keyword(s):  
Magnetic Field ◽  
Boundary Layer ◽  
Nusselt Number ◽  
Volume Fraction ◽  
Vertical Cylinder ◽  
Skin Friction Coefficient ◽  
Free Convective Flow ◽  
Local Skin ◽  
Content Type ◽  
Local Skin Friction

Purpose The purpose of this paper is to study numerically the influence of a magnetic field on the transient free convective boundary layer flow of a nanofluid over a moving semi-infinite vertical cylinder with heat transfer Design/methodology/approach The problem is governed by the coupled non-linear partial differential equations with appropriate boundary conditions. The fluid is a water-based nanofluid containing nanoparticles of copper. The Brinkman model for dynamic viscosity and Maxwell–Garnett model for thermal conductivity are used. The governing boundary layer equations are written according to The Tiwari–Das nanofluid model. A robust, well-tested, implicit finite difference method of Crank–Nicolson type, which is unconditionally stable and convergent, is used to find the numerical solutions of the problem. The velocity and temperature profiles are studied for significant physical parameters such as the magnetic parameter, nanoparticles volume fraction and the thermal Grashof number Gr. The local skin-friction coefficient and the Nusselt number are also analysed and presented graphically. Findings The present computations have shown that an increase in the values of either magnetic parameter M or nanoparticle volume fraction decreases the local skin-friction coefficient, whereas the opposite effect is observed for thermal Grashof number Gr. The local Nusselt number increases with a rise in Gr and ϕ values. But an increase in M reduces the local Nusselt number. Originality/value This paper is relatively original and presents numerical investigation of transient two-dimensional laminar boundary layer free convective flow of a nanofluid over a moving semi-infinite vertical cylinder in the presence of an applied magnetic field. The present study is of immediate application to all those processes which are highly affected by heat enhancement concept and a magnetic field. Further the present study is relevant to nanofluid materials processing, chemical engineering coating operations exploiting nanomaterials and others.

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