Natural convection of fluid with variable viscosity and viscous dissipation from a heated vertical wavy surface in presence of magnetic field

2020 ◽  
Vol 17 (2) ◽  
pp. 101-113
Author(s):  
Nazma Parveen ◽  
M. A. Alim
Keyword(s):  
Magnetic Field ◽  
Nusselt Number ◽  
Natural Convection ◽  
Skin Friction ◽  
Viscous Dissipation ◽  
Local Nusselt Number ◽  
Variable Viscosity ◽  
Wavy Surface ◽  
Numerical Work ◽  
Dissipation Parameter

ABSTRACT   The present numerical work describes the effect of the temperature dependent variable viscosity and viscous dissipation on natural convection heat transfer boundary layer flow of a viscous incompressible electrically conducting fluid along a vertical wavy surface in presence of a transverse magnetic field. The wavy surface is maintained at uniform wall temperature that is higher than that of the ambient. A simple coordinate transformation is employed to transform the wavy surface into a flat plate. A marching finite difference scheme is used for present analysis. The numerical results, including the developments of the skin friction coefficients, the local Nusselt number, the streamlines as well as the isotherms are presented and discussed in detail. The results of this investigation illustrated that the skin friction coefficient increase with an increase of the variable viscosity and viscous dissipation parameter, while the local Nusselt number at the heated surface decrease with increasing values of variable viscosity, intensity of magnetic field and viscous dissipation parameter.

Effects of Viscous Dissipation and Joule Heating on Natural Convection Flow of a Viscous Fluid from Heated Vertical Wavy Surface

2011 ◽  
Vol 66 (6-7) ◽  
pp. 427-440 ◽  
Author(s):  
Nasser S. Elgazery ◽  
Nader Y. Abd Elazem
Keyword(s):  
Nusselt Number ◽  
Natural Convection ◽  
Skin Friction ◽  
Viscous Dissipation ◽  
Joule Heating ◽  
Wavy Surface ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Local Skin ◽  
Local Skin Friction

A mathematical model will be analyzed in order to study the effects of viscous dissipation and Ohmic heating (Joule heating) on magnetohydrodynamic (MHD) natural convection flow of a temperature dependent viscosity from heated vertical wavy surface. The present physical problem is studied numerically by using the appropriate variables, which reduce the complex wavy surface into a flat one. An implicit marching Chebyshev collocation scheme is employed for the analysis. Numerical solutions are obtained for velocity, temperature, local skin friction, and Nusselt number for a selection of parameter sets consisting of Eckert number, Prandtl number, MHD variation, and amplitude-wavelength ratio parameter. Numerical results show that these parameters have significant influences on the velocity and the temperature profiles as well as for the local skin friction and Nusselt number

Chemically Reacting MHD Mixed Convection Variable Viscosity Blasius Flow Embedded in a Porous Medium

2017 ◽  
Vol 374 ◽  
pp. 83-91 ◽  
Author(s):  
Oluwole Daniel Makinde ◽  
S.R. Mishra
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Nusselt Number ◽  
Mixed Convection ◽  
Skin Friction ◽  
Sherwood Number ◽  
Variable Viscosity ◽  
Fluid Viscosity ◽  
Reaction Heat ◽  
Blasius Flow

In this paper, the combined effects of magnetic field, buoyancy forces, nth order chemical reaction, heat source, viscous dissipation, Joule heating and variable viscosity on mixed convection Blasius flow of a conducting fluid over a convectively heated permeable plate embedded in a porous medium is investigated. The fluid properties are assumed to be constant except for the density variation with the temperature and reacting chemical species concentration. The nonlinear governing differential equations were obtained and solved numerically using the Runge-Kutta-Fehlberg method with shooting technique. The dimensionless velocity, temperature and concentration profiles are shown graphically. The effects of pertinent parameters on the skin friction, Nusselt number and Sherwood number are examined. It is found that skin friction decreases while Nusselt number and Sherwood number increase with a decrease in the fluid viscosity in the presence of magnetic field.

scholarly journals Computational analysis of viscous dissipation and joule-heating effects on non-Darcy MHD natural convection flow from a horizontal cylinder in porous media with internal heat generation

2014 ◽  
Vol 41 (1) ◽  
pp. 37-70 ◽  
Author(s):  
Ramachandra Prasad ◽  
Subba Rao ◽  
Anwar Bég
Keyword(s):  
Natural Convection ◽  
Heat Source ◽  
Skin Friction ◽  
Viscous Dissipation ◽  
Joule Heating ◽  
Local Skin ◽  
Grashof Number ◽  
Dissipation Parameter ◽  
Local Skin Friction ◽  
Source Sink

In the present paper we examine the effects of viscous dissipation, Joule heating and heat source/sink on non-Darcy MHD natural convection heat transfer flow over permeable horizontal circular cylinder in a porous medium. The boundary layer equations, which are parabolic in nature, are normalized into non-similar form and then solved numerically with the well-tested, efficient, implicit, stable Keller-box finite difference scheme. A parametric study illustrating the influence of Darcy parameter (Da), Forchheimer parameter (?), Grashof number(Gr), heat source/sink parameter (?) and viscous dissipation parameter (Ec) on the fluid velocity, temperature as well as local skin-friction and Nusselt numbers is conducted Increasing Forchheimer inertial drag parameter (?) retards the flow considerably but enhances temperatures. Increasing viscous dissipation parameter(Ec) is found to elevate velocities i.e. accelerate the flow and increase temperatures. Increasing heat source/sink parameter (?) is found to elevate velocities and increase temperatures. Increasing the Grashof number (Gr) is found to elevate the velocity and decrease the temperatures. Local skin friction number is found to be increases with increasing heat source/sink parameter (?) where as Local Nusselt number is found to decrease with increasing heat source/sink parameter (?).

scholarly journals Natural Convection Flow of MHD Micropolar Fluid Along a Vertical Wavy Surface

2017 ◽  
Vol 65 (2) ◽  
pp. 91-96
Author(s):  
S Sultana ◽  
Nepal C Roy
Keyword(s):  
Nusselt Number ◽  
Natural Convection ◽  
Skin Friction ◽  
Micropolar Fluid ◽  
Couple Stress ◽  
Magnetic Parameter ◽  
Wavy Surface ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Viscosity Parameter

We study the boundary layer characteristics of natural convection flow of an electrically conducting micropolar fluid along a vertical wavy surface. The dimensionless governing equations have been solved numerically. Results are presented in terms of the local skin-friction coefficient, the local Nusselt number and the local couple stress with the variation of amplitude-wavelength ratio, magnetic parameter, vortex viscosity parameter and spin-gradient viscosity parameter. Due to increase of the amplitude wave-length ratio, the skin-friction and the couple stress are found to decrease whereas the Nusselt number increases. The skin friction and the couple stress increase but the Nusselt number decreases for increasing values of vortex viscosity parameter. In addition, when the spin-gradient viscosity is increased, the maximum values of the Nusselt number and the couple stress significantly increase but the skin-friction decreases. The magnetic parameter considerably reduces the skin-friction, Nusselt number and couple stress. Dhaka Univ. J. Sci. 65(2): 91-96, 2017 (July)

Magnetohydrodynamic (MHD) mixed convection stagnation point flow of a nanofluid over a vertical plate with viscous dissipation

2015 ◽  
Vol 93 (11) ◽  
pp. 1365-1374 ◽  
Author(s):  
Irfan Mustafa ◽  
Tariq Javed ◽  
Abid Majeed
Keyword(s):  
Nusselt Number ◽  
Friction Coefficient ◽  
Mixed Convection ◽  
Skin Friction ◽  
Viscous Dissipation ◽  
Local Nusselt Number ◽  
Vertical Plate ◽  
Volume Fraction ◽  
Skin Friction Coefficient ◽  
Flow Case

In this study, magnetohydrodynamic effects on the mixed convection flow of nanofluid particles, namely, Cu (copper) and Al2O3 (alumina) near a stagnation region over a vertical plate in the presence of viscous dissipation is investigated. The governing equations of the nanofluid flow model proposed by Tiwari and Das (Int. J. Heat Mass Transfer, 50, 2002 (2007). doi:10.1016/j.ijheatmasstransfer.2006.09.034) are converted into a dimensionless nonlinear system of ordinary differential equations by using the similarity transformation. The solution of the resulting equations is obtained numerically by using a very efficient implicit scheme known as the Keller box method. A comparison with previous studies is shown in tabular form and excellent agreement is found. The effects of pertinent parameters like magnetic parameter M, Eckert number Ec, and volume fraction parameter ϕ on velocity, temperature, skin friction coefficient, and local Nusselt number with fixed value of Prandtl number Pr = 6.2 are shown graphically and discussed. These results show that the skin friction coefficient increases for both nanoparticles in assisting and opposing flow cases because of increasing absolute values of M and Ec, on the other hand heat transfer rate is enhanced in the opposing flow case and reduced in the assisting flow case. The values of skin friction coefficient for both nanoparticles, namely, Cu and Al2O3 increase with the increase in volume fraction parameter ϕ in both assisting and opposing flow cases and Cu has a higher value than Al2O3. The same behavior is observed for local Nusselt number in opposing flow, but in assisting flow the value of local Nusselt number decreases with the increase of ϕ in the presence of magnetic and viscous dissipation effects and Cu has a smaller value than Al2O3.

scholarly journals Viscous Dissipation Effects on MHD Natural Convection Flow along a Sphere

1970 ◽  
Vol 36 ◽  
pp. 44-48 ◽  
Author(s):  
Md. M Alam ◽  
MA Alim ◽  
Md. MK Chowdhury
Keyword(s):  
Nusselt Number ◽  
Natural Convection ◽  
Viscous Dissipation ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Local Skin ◽  
Boundary Layer Equations ◽  
Box Scheme ◽  
Dissipation Parameter ◽  
Local Skin Friction

In this paper, we describe the viscous dissipation effects in magnetohydrodynamic (MHD) natural convection flow on a sphere. The natural convection laminar flow from a sphere immersed in a viscous incompressible optically thin fluid in the presence of magnetic field has been investigated. The governing boundary layer equations are first transformed into a non-dimensional form and the resulting nonlinear system of partial differential equations are then solved numerically using a very efficient finite-difference method with Keller-box scheme. Here we have focused our attention on the evolution of shear stress in terms of the local skin friction and the rate of heat transfer in terms of local Nusselt number, velocity profiles as well as temperature profiles for some selected parameters consisting of magnetic parameter M, viscous dissipation parameter N and the Prandlt number Pr.Keywords: Viscous dissipation, magnetohydrodynamics, natural convection, Nusselt number. Journal of Mechanical Engineering Vol.36 Dec. 2006 pp.44DOI = 10.3329/jme.v36i0.810

scholarly journals THERMAL RADIATION EFFECT ON MHD NATURAL CONVECTION BOUNDARY LAYER FLOW OVER A PLATE WITH SUCTION (INJECTION) AND VARIABLE VISCOSITY

2017 ◽  
Vol 5 (4RAST) ◽  
pp. 52-58
Author(s):  
Jalaja P ◽  
Venkataramana B.S ◽  
Naveen V ◽  
K.R. Jayakumar
Keyword(s):  
Magnetic Field ◽  
Boundary Layer ◽  
Natural Convection ◽  
Thermal Radiation ◽  
Boundary Layer Flow ◽  
Variable Viscosity ◽  
Convection Boundary Layer ◽  
Implicit Finite Difference Scheme ◽  
Convection Boundary ◽  
Layer Flow

The effect of thermal radiation on steady natural convection boundary layer flow over a plate with variable viscosity and magnetic field has been studied in this paper. The effect of suction and injection is also considered in the investigation. The system of partial differential equations governing the nonsimilar flow has been solved numerically using implicit finite difference scheme along with a quasilinearization technique. The thermal radiation has significant effect on heat transfer coefficient and thermal transport in presence of viscosity variation parameter and magnetic field in case of suction and injection.

scholarly journals EFFECT OF HEAT AND MASS TRANSFER AND THERMAL RADIATION ON A STEADY MHD CONVECTIVE FLOW WITH VISCOUS DISSIPATION AND SUCTION/INJECTION

2022 ◽  
Vol 52 (1) ◽  
pp. 35-41
Author(s):  
Silpisikha Goswami ◽  
Kamalesh Kumar Pandit ◽  
Dipak Sarma
Keyword(s):  
Nusselt Number ◽  
Thermal Radiation ◽  
Temperature Profile ◽  
Skin Friction ◽  
Viscous Dissipation ◽  
Sherwood Number ◽  
Fluid Velocity ◽  
Physical Parameters ◽  
Flow Equations ◽  
The Impact

Our motive is to examine the impact of thermal radiation and suction or injection with viscous dissipation on an MHD boundary layer flow past a vertical porous stretched sheet immersed in a porous medium. The set of the flow equations is converted into a set of non-linear ordinary differential equations by using similarity transformation. We use Runge Kutta method and shooting technique in MATLAB Package to solve the set of equations. The impact of non-dimensional physical parameters on flow profiles is analysed and depicted in graphs. We observe the influence of non-dimensional physical quantities on the Nusselt number, the Sherwood number, and skin friction and presented in tables. A comparison of the obtained numerical results with existing results in a limiting sense is also presented. We enhance radiation to observe the deceleration of fluid velocity and temperature profile for both suction and injection. While enhancing porosity parameter accelerates velocity whereas decelerates temperature profile. As the heat source parameter increases, the temperature of the fluid decreases for both suction and injection, it has been found. With the increasing values of the radiation parameter, the skin friction and heat transfer rate decreases. Increasing magnetic parameter decelerates the skin friction, Nusselt number, and Sherwood number.

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