scholarly journals Effects of viscous dissipation and boundary wall thickness on steady natural convection Couette flow with variable viscosity and thermal conductivity

2020 ◽  
Vol 7-8 ◽  
pp. 100052
Author(s):  
Abiodun O. Ajibade ◽  
Ayuba M. Umar
Keyword(s):  
Thermal Conductivity ◽  
Natural Convection ◽  
Couette Flow ◽  
Viscous Dissipation ◽  
Wall Thickness ◽  
Variable Viscosity ◽  
Boundary Wall

scholarly journals COMBINED EFFECTS OF VARIABLE VISCOSITY, VISCOUS DISSIPATION AND THERMAL RADIATION ON UNSTEADY NATURAL CONVECTION COUETTE FLOW THROUGH A VERTICAL POROUS CHANNEL

2020 ◽  
Vol 4 (2) ◽  
pp. 135-150
Author(s):  
Yusuf A. Bichi ◽  
A. O. Ajibade
Keyword(s):  
Natural Convection ◽  
Differential Equations ◽  
Thermal Radiation ◽  
Couette Flow ◽  
Viscous Dissipation ◽  
Variable Viscosity ◽  
Porous Channel ◽  
Combined Effects ◽  
Flow Through ◽  
Unsteady Natural Convection

The present article investigates combined effects of variable viscosity, viscous dissipation and thermal radiation on unsteady natural convection Couette flow through vertical porous channel. Non-linear Rosseland heat diffusion is deployed for the solution of the flow equations which as a consequence; together with the effects of variable viscosity, viscous dissipation and thermal radiation have resulted to high non-linear equations for the flow formation. Appropriate similarity variables are used to convert the partial differential equations associated with the fluid formation into dimensionless ordinary differential equations (ODEs) and the emerging ODEs are solved using Adomian decomposition method (ADM) and computer aided algebra package. Influences of the physical parameters involved in the problem are presented, discussed and conclusions are drawn. During the investigation; it was found that the fluid velocity and temperature were found to increase with increase in Eckert number, viscosity variation and thermal radiation.

Effects of Variable Viscosity and Thermal conductivity on Natural-Convection of Nanofluids Past a Vertical Plate in Porous Media

2013 ◽  
Vol 30 (3) ◽  
pp. 265-275 ◽  
Author(s):  
A. Noghrehabadi ◽  
M. Ghalambaz ◽  
A. Ghanbarzadeh
Keyword(s):  
Thermal Conductivity ◽  
Brownian Motion ◽  
Natural Convection ◽  
Differential Equations ◽  
Vertical Plate ◽  
Volume Fraction ◽  
Variable Viscosity ◽  
Increase With Increase ◽  
Dimensional Parameters ◽  
Brownian Motion And Thermophoresis

ABSTRACTThe effects of variable viscosity and thermal conductivity on the natural convection heat transfer over a vertical plate embedded in a porous medium saturated by a nanofluid are investigated. In the nanofluid model, a gradient of nanoparticles concentration because of Brownian motion and thermophoresis forces is taken into account. The nanofluid viscosity and the thermal conductivity are assumed as a function of local nanoparticles volume fraction. The appropriate similarity variables are used to convert the governing partial differential equations into a set of highly coupled nonlinear ordinary differential equations, and then, they numerically solved using the Runge-Kutta-Fehlberg method. The practical range of non- dimensional parameters is discussed. The results show that the range of Lewis number as well as Brownian motion and thermophoresis parameters which were used in previous studies should be reconsidered. The effect of non-dimensional parameters on the boundary layer is examined. The results show that the reduced Nusselt number would increase with increase of viscosity parameter and would decrease with increase of thermal conductivity parameter.

Viscous dissipation effect on steady natural convection Couette flow with convective boundary condition

2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Abiodun O. Ajibade ◽  
Tafida M. Kabir
Keyword(s):  
Boundary Condition ◽  
Natural Convection ◽  
Couette Flow ◽  
Viscous Dissipation ◽  
Fluid Velocity ◽  
Convective Boundary Condition ◽  
Heated Plate ◽  
Fluid Temperature ◽  
Convective Boundary ◽  
Energy And Momentum

Abstract The present article explores the effect of viscous dissipation on steady natural convection Couette flow subject to convective boundary condition. Due to the nonlinearity and coupling of the governing equations in the present situation, the homotopy perturbation method was employed to obtain the solutions of the energy and momentum equations. The impacts of the controlling parameters were investigated and discussed graphically. In the course of investigation, it was found that fluid temperature increases with an increase in viscous dissipation while the reverse trend was observed in fluid velocity. However, it was also discovered that heat generation leads to a decrease in the rate of heat transfer on the heated plate and it increases on the cold plate. Finally, it was concluded that the velocity boundary layer thickness increases with an increase in Biot number.

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.

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