Laminar Natural Convection of Bingham Fluids in a Square Enclosure with Vertical Walls Subjected to Constant Heat Flux

2011 ◽  
Vol 60 (5) ◽  
pp. 381-409 ◽  
Author(s):  
Osman Turan ◽  
Anuj Sachdeva ◽  
Robert J. Poole ◽  
Nilanjan Chakraborty
1999 ◽  
Vol 121 (1) ◽  
pp. 57-62 ◽  
Author(s):  
A. F. Emery ◽  
J. W. Lee

Natural convection in a square enclosure with heated vertical walls and temperature-dependent conductivity and viscosity was simulated for Prandtl numbers ranging from 0.01 to 1.0 and Ra ≤ 106. Although the variable properties produced observable changes in the the temperatures and velocities, the overall heat transfer, as represented by the Nusselt number, was found to be unaffected and was accurately correlated in terms of the Rayleigh and Prandtl numbers using Nu=0.185Ra00.278Pr00.089 with properties evaluated at the average temperature. This correlation applies to both isothermal and constant heat flux hot walls.


2017 ◽  
Vol 9 (2) ◽  
pp. 463-484 ◽  
Author(s):  
Ammar I. Alsabery ◽  
Habibis Saleh ◽  
Ishak Hashim

AbstractEffects of viscous dissipation and radiation on MHD natural convection in oblique porous cavity with constant heat flux is studied numerically in the present article. The right inclined wall is maintained at a constant cold temperatureTcand the left inclined wall has a constant heat fluxqwith lengthS, while the remainder of the left wall is adiabatic. The horizontal walls are assumed to be adiabatic. The governing equations are obtained by applying the Darcy model and Boussinesq approximations. COMSOL's finite element method is used to solve the non-dimensional governing equations together with specified boundary conditions. The governing parameters of this study are Rayleigh number (Ra=10,100,200,250,500 and 1000), Hartmann number (0≤Ha≤20), inclination angle of the magnetic field (0° ≤ω≤π/2), Radiation (0≤R≤15), the heater flux length (0.1≤H≤1) and inclination angle of the sloping wall (–π/3≤ϕ≤π/3). The results are considered for various values of the governing parameters in terms of streamlines, isotherms and averageNusselt number. It is found that the intensity of the streamlines and the isotherm patterns decrease with an increment in Hartmann number. The overall heat transfer is significantly increased with the increment of the viscous dissipation and the radiation parameters.


Author(s):  
G. Tomita ◽  
M. Kaneda ◽  
T. Tagawa ◽  
H. Ozoe

Three-dimensional numerical computations were carried out for the natural convection of air in a horizontal cylindrical enclosure in a magnetic field, which is modeled for a bore space of a horizontal superconducting magnet. The enclosure was cooled from the circumferential sidewall at the constant heat flux and vertical end walls were thermally insulated. A strong magnetic field was considered by a one-turn electric coil with the concentric and twice diameter of the cylinder. Without a magnetic field, natural convection occurs along the circumferential sidewall. When a magnetic field was applied, magnetizing force induced the additional convection, that is, the cooled air at the circumferential wall was attracted to the location of a coil. Consequently, the temperature around the coil decreased extensively.


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