Unsteady hydromagnetic flow of a viscoelastic fluid with temperature-dependent viscosity

2002 ◽  
Vol 80 (9) ◽  
pp. 1015-1024 ◽  
Author(s):  
A L Aboul-Hassan ◽  
H A Attia
Keyword(s):  
Viscoelastic Fluid ◽  
Energy Equation ◽  
Transverse Magnetic ◽  
Fluid Viscosity ◽  
Hydromagnetic Flow ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Different Temperatures ◽  
Horizontal Pressure ◽  
Dependent Viscosity

The flow of a conducting, viscoelastic fluid between two horizontal porous plates in the presence of a transverse-magnetic field is studied. The plates are assumed to be nonconducting and maintained at two fixed but different temperatures. The fluid viscosity is assumed to be temperature dependent and the fluid is subjected to a uniform suction from above and injection from below. The motion of the fluid is produced by a uniform horizontal pressure gradient. The equation of motion and the energy equation are solved numerically to yield the velocity and temperature distributions. PACS Nos.: 44.05+e, 44.10+i, 44.15+a, 44.20+b, 4435+c, 47.11+j, 47.15-x, 47.15cb, 47.60+i, 47.65+a

Heat Transfer in Turbulent Pipe Flow for Liquids Having a Temperature-Dependent Viscosity

1978 ◽  
Vol 100 (2) ◽  
pp. 224-229 ◽  
Author(s):  
O. T. Hanna ◽  
O. C. Sandall
Keyword(s):  
Heat Transfer ◽  
Friction Factor ◽  
Pipe Flow ◽  
Turbulent Pipe Flow ◽  
Fluid Viscosity ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Analytical Approximations ◽  
Constant Viscosity ◽  
Dependent Viscosity

Analytical approximations are developed to predict the effect of a temperature-dependent viscosity on convective heat transfer through liquids in fully developed turbulent pipe flow. The analysis expresses the heat transfer coefficient ratio for variable to constant viscosity in terms of the friction factor ratio for variable to constant viscosity, Tw, Tb, and a fluid viscosity-temperature parameter β. The results are independent of any particular eddy diffusivity distribution. The formulas developed here represent an analytical approximation to the model developed by Goldmann. These approximations are in good agreement with numerical solutions of the model nonlinear differential equation. To compare the results of these calculations with experimental data, a knowledge of the effect of variable viscosity on the friction factor is required. When available correlations for the friction factor are used, the results given here are seen to agree well with experimental heat transfer coefficients over a considerable range of μw/μb.

Thermal radiation and buoyancy effects on MHD free convective heat generating flow over an accelerating permeable surface with temperature-dependent viscosity

2001 ◽  
Vol 79 (4) ◽  
pp. 725-732 ◽  
Author(s):  
M A Seddeek
Keyword(s):  
Thermal Radiation ◽  
Shooting Method ◽  
Skin Friction Coefficient ◽  
Permeable Surface ◽  
Fluid Viscosity ◽  
Governing Equations ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Thermal Buoyancy ◽  
Dependent Viscosity

The paper presents a study of the flow of a viscous incompressible fluid over an accelerating permeable surface with temperature-dependent viscosity, taking into account the effect of thermal radiation and thermal buoyancy in the presence of a magnetic field. The fluid viscosity is assumed to vary as an inverse linear function of temperature. The governing equations for laminar free convection of fluid are changed to dimensionless ordinary differential equations by similarity transformation. They are solved by a shooting method. The effects of various parameters on the velocity and temperature profiles as well as the skin friction coefficient and wall heat transfer are presented graphically and in tabulated form. PACS Nos.: 47.65ta, 52.30–q

scholarly journals Magneto Hydrodynamic Incompressible Laminar Flow With Temperature Dependent Viscosity Between Two Parallel Porous Walls

2019 ◽  
Keyword(s):  
Temperature Distribution ◽  
Laminar Flow ◽  
Incompressible Fluid ◽  
Energy Equation ◽  
Constant Pressure ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Porous Walls ◽  
Effects Of Temperature ◽  
Dependent Viscosity

This paper studied Magneto hydrodynamics viscious, incompressible fluid bounded by the parallel non-conducting porous walls. The viscousity of the fluid is assumed to be temperature dependent. The fluid is subjected to a constant pressure gradient and an external uniformmagnetic field perpendicular to the walls. The two walls are kept different but constant temperature while the Joule and viscious dissipation are included in the energy equation. Graphs were presented to show the effects of temperature depentent viscosity on both the velocity and temperature distribution.

The linear stability of channel flow of fluid with temperature-dependent viscosity

1996 ◽  
Vol 323 ◽  
pp. 107-132 ◽  
Author(s):  
D. P. Wall ◽  
S. K. Wilson
Keyword(s):  
Linear Stability ◽  
Channel Flow ◽  
Finite Difference Methods ◽  
Fluid Viscosity ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Viscosity Models ◽  
Shape Effects ◽  
The Stability ◽  
Dependent Viscosity

The classical fourth-order Orr-Sommerfeld problem which arises from the study of the linear stability of channel flow of a viscous fluid is generalized to include the effects of a temperature-dependent fluid viscosity and heating of the channel walls. The resulting sixth-order eigenvalue problem is solved numerically using high-order finite-difference methods for four different viscosity models. It is found that temperature effects can have a significant influence on the stability of the flow. For all the viscosity models considered a non-uniform increase of the viscosity in the channel always stabilizes the flow whereas a non-uniform decrease of the viscosity in the channel may either destabilize or, more unexpectedly, stabilize the flow. In all the cases investigated the stability of the flow is found to be only weakly dependent on the value of the Péclet number. We discuss our results in terms of three physical effects, namely bulk effects, velocity-profile shape effects and thin-layer effects.

scholarly journals Effect of thermal radiation on natural convection in a square porous cavity filled with a fluid of temperature-dependent viscosity

2018 ◽  
Vol 22 (1 Part B) ◽  
pp. 391-399 ◽  
Author(s):  
Marina Astanina ◽  
Mikhail Sheremet ◽  
Jawali Umavathi
Keyword(s):  
Natural Convection ◽  
Thermal Radiation ◽  
Numerical Study ◽  
Darcy Number ◽  
Radiation Parameter ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Porous Cavity ◽  
Different Temperatures ◽  
Dependent Viscosity

A numerical study of the natural convection combined with thermal radiation inside a square porous cavity filled with a fluid of temperature-dependent viscosity is carried out. The side horizontal walls are assumed to be adiabatic while both the left and right vertical walls are kept at constant but different temperatures. The Rosseland diffusion approximation is used to describe the radiative heat flux in the energy equation. The governing equations formulated in dimensionless stream function, vorticity, and temperature variables are solved using finite difference method. A parametric analysis illustrating the effects of the radiation parameter (0 ? Rd ? 10), Darcy number (10?5 ? Da ? 10?2), and viscosity variation parameter (0 ? C ? 6) on fluid flow and heat transfer is implemented. The results show an essential intensification of convective flow with an increase in the radiation parameter.

Sign in / Sign up

Export Citation Format

Share Document