Radiation Effect on the Mixed Convection Flow of a Viscoelastic Fluid Along an Inclined Stretching Sheet

2012 ◽  
Vol 67 (3-4) ◽  
pp. 195-202 ◽  
Author(s):  
Muhammad Qasim ◽  
Tasawar Hayat ◽  
Saleem Obaidat
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Viscoelastic Fluid ◽  
Radiative Heat ◽  
Heat Transfer Analysis ◽  
Convection Flow ◽  
Viscoelastic Parameter ◽  
Homotopy Analysis ◽  
Rosseland Approximation ◽  
Momentum Boundary Layer

This study concentrates on the heat transfer analysis of the steady flow of viscoelastic fluid along an inclined stretching surface. Analysis has been carried out in the presence of thermal radiation and the Rosseland approximation is used to describe the radiative heat flux in the energy equation. The equations of continuity, momentum and energy are reduced into the system of governing differential equations and solved by homotopy analysis method (HAM). The velocity and temperature are illustrated through graphs. Exact and homotopy solutions are compared in a limiting sense. It is noticed that viscoelastic parameter decreases the velocity and boundary layer thickness. It is also observed that increasing values of viscoelastic parameter reduces the thickness of momentum boundary layer and increase the heat transfer rate. However, it is found that increasing the radiation parameter has the effect of decreasing the local Nusselt number

Mixed Convection Flow of Viscoelastic Fluid over a Sphere under Convective Boundary Condition Embedded in Porous Medium

2015 ◽  
Vol 362 ◽  
pp. 67-75 ◽  
Author(s):  
A.R.M. Kasim ◽  
L.Y. Jiann ◽  
N.A. Rawi ◽  
A. Ali ◽  
S. Shafie
Keyword(s):  
Boundary Layer ◽  
Boundary Condition ◽  
Porous Medium ◽  
Boundary Conditions ◽  
Mixed Convection ◽  
Viscoelastic Fluid ◽  
Convective Boundary Condition ◽  
Convection Flow ◽  
Convective Boundary ◽  
Viscoelastic Parameter

The investigation on mixed convection boundary layer of a viscoelastic fluid over a sphere which is embedded in porous medium under convective boundary condition is carried out in this paper. The boundary layer equations of viscoelastic fluid are an order higher than Newtonian (viscous) fluid and the adherence boundary conditions are insufficient to determine the solution of these equations completely. Hence, the augmentation on extra boundary conditions is needed in order to solve this problem. The governing partial differential equations are first transformed into non-dimensional forms and then solved numerically using the Keller-box method by augmenting extra boundary conditions at infinity. The numerical results obtained for limiting case are comparing with related outcomes in order to validate the present results. Results on the effects of the viscoelastic parameter in the presence of porosity and mixed convection on the skin friction and heat transfer as well as velocity and temperature profile have been discussed.

Effects of Radiation and Variable Thermal Conductivity on the MHD Flow of a Viscoelastic Fluid and Heat Transfer Over a Stretching Porous Sheet

2008 ◽  
Author(s):  
P. Anuradha ◽  
S. Krishnambal
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Boundary Layer ◽  
Prandtl Number ◽  
Viscoelastic Fluid ◽  
Variable Thermal Conductivity ◽  
Integration Scheme ◽  
Viscoelastic Parameter ◽  
Porous Sheet ◽  
Effects Of Radiation

A numerical study on the effects of radiation and variable thermal conductivity on the flow and heat transfer in the boundary layer of a viscoelastic fluid (Walters’ liquid B’ model) over a stretching porous sheet in the presence of a magnetic field is studied. The momentum differential equation is solved exactly. Two cases of sheet surface conditions are considered — (i) PST case involving prescribed surface temperature and (ii) PHF case involving prescribed heat flux at the surface. The energy equation is solved with the application of the shooting technique using the fourth order Runge-Kutta integration scheme. Numerical results are obtained for various values of non-dimensional parameters — which include among others, the Prandtl number (P), the Eckert number (E) and the Radiation number (N). The significant conclusions are: (1) the momentum boundary layer can be minimized by considering the sheet to be influenced by a continuous suction of the fluid through the porous boundary and by choosing large values for the viscoelastic parameter and the magnetic parameter (2) an ideal combination for faster cooling of the thermal boundary layer would be to consider the suction velocity of the fluid along with a large value for the Prandtl number combined with small values for Radiation and Eckert numbers.

scholarly journals Natural Convection Flow in a Strong Cross Magnetic Field With Radiation

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
S. Siddiqa ◽  
M. A. Hossain ◽  
Suvash C. Saha
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Boundary Layer ◽  
Natural Convection ◽  
Finite Difference ◽  
Radiative Heat ◽  
Liquid Metals ◽  
Convection Flow ◽  
Convection Boundary Layer ◽  
Physical Parameters

The problem of magnetohydrodynamic natural convection boundary layer flow of an electrically conducting and optically dense gray viscous fluid along a heated vertical plate is analyzed in the presence of strong cross magnetic field with radiative heat transfer. In the analysis radiative heat flux is considered by adopting optically thick radiation limit. Attempt is made to obtain the solutions valid for liquid metals by taking Pr ≪1. Boundary layer equations are transformed in to a convenient dimensionless form by using stream function formulation (SFF) and primitive variable formulation (PVF). Nonsimilar equations obtained from SFF are then simulated by implicit finite difference (Keller-box) method whereas parabolic partial differential equations obtained from PVF are integrated numerically by hiring direct finite difference method over the entire range of local Hartmann parameter, ξ. Further, asymptotic solutions are also obtained for large and small values of local Hartmann parameter ξ. A favorable agreement is found between the results for small, large and all values of ξ. Numerical results are also demonstrated graphically by showing the effect of various physical parameters on shear stress, rate of heat transfer, velocity, and temperature.

Effect of Nanofluid on Heat Transfer Enhancement for Mixed Convection Flow Over a Corrugated Surface

2020 ◽  
Vol 45 (4) ◽  
pp. 373-383
Author(s):  
Nepal Chandra Roy ◽  
Sadia Siddiqa
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Nusselt Number ◽  
Mixed Convection ◽  
Local Nusselt Number ◽  
Richardson Number ◽  
Thermal Boundary Layer ◽  
Volume Fraction ◽  
Convection Flow ◽  
Mixed Convection Flow

AbstractA mathematical model for mixed convection flow of a nanofluid along a vertical wavy surface has been studied. Numerical results reveal the effects of the volume fraction of nanoparticles, the axial distribution, the Richardson number, and the amplitude/wavelength ratio on the heat transfer of Al2O3-water nanofluid. By increasing the volume fraction of nanoparticles, the local Nusselt number and the thermal boundary layer increases significantly. In case of \mathrm{Ri}=1.0, the inclusion of 2 % and 5 % nanoparticles in the pure fluid augments the local Nusselt number, measured at the axial position 6.0, by 6.6 % and 16.3 % for a flat plate and by 5.9 % and 14.5 %, and 5.4 % and 13.3 % for the wavy surfaces with an amplitude/wavelength ratio of 0.1 and 0.2, respectively. However, when the Richardson number is increased, the local Nusselt number is found to increase but the thermal boundary layer decreases. For small values of the amplitude/wavelength ratio, the two harmonics pattern of the energy field cannot be detected by the local Nusselt number curve, however the isotherms clearly demonstrate this characteristic. The pressure leads to the first harmonic, and the buoyancy, diffusion, and inertia forces produce the second harmonic.

scholarly journals Heat Transfer to MHD Oscillatory Viscoelastic Flow in a Channel Filled with Porous Medium

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Rita Choudhury ◽  
Utpal Jyoti Das
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Porous Medium ◽  
Radiative Heat ◽  
Saturated Porous Medium ◽  
Transverse Magnetic ◽  
Viscoelastic Flow ◽  
Viscoelastic Parameter ◽  
Flow Parameters ◽  
The Magnetic Field

The combined effect of a transverse magnetic field and radiative heat transfer on unsteady flow of a conducting optically thin viscoelastic fluid through a channel filled with saturated porous medium and nonuniform walls temperature has been discussed. It is assumed that the fluid has small electrical conductivity and the electromagnetic force produced is very small. Closed-form analytical solutions are constructed for the problem. The effects of the radiation and the magnetic field parameters on velocity profile and shear stress for different values of the viscoelastic parameter with the combination of the other flow parameters are illustrated graphically, and physical aspects of the problem are discussed.

scholarly journals Radiative Heat Transfer Analysis in a Marine Boiler Furnace

1986 ◽  
Vol 21 (5) ◽  
pp. 311-316
Author(s):  
Hiroshi Hayasaka ◽  
Kazuhiko Kudo ◽  
Hiroshi Taniguchi ◽  
Noboru Okigami ◽  
Taketoshi Takahashi ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Radiative Heat Transfer ◽  
Radiative Heat ◽  
Heat Transfer Analysis ◽  
Boiler Furnace ◽  
Marine Boiler
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