scholarly journals Effects of Radiation and Heat Generation/Absorption on MHD Free Convective Heat Transfer of Power-Law Non-Newtonian Fluids Along a Power-Law Stretching Sheet with Uniform Surface Heat Flux

2013 ◽  
Vol 5 (2) ◽  
pp. 519-530
Author(s):  
M.A. Samad ◽  
M.R. Hossain
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Heat Generation ◽  
Power Law ◽  
Surface Heat Flux ◽  
Stretching Sheet ◽  
Surface Heat ◽  
Effects Of Radiation

Effect of Edge Conditions on Natural Convective Heat Transfer From a Narrow Vertical Flat Plate With a Uniform Surface Heat Flux

2007 ◽  
Author(s):  
Patrick H. Oosthuizen ◽  
Jane T. Paul
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Surface Heat Flux ◽  
Three Dimensional ◽  
Surface Heat ◽  
Heated Plate ◽  
Two Dimensional ◽  
Adiabatic Surface

Two-dimensional natural convective heat transfer from vertical plates has been extensively studied. However, when the width of the plate is relatively small compared to its height, the heat transfer rate can be greater than that predicted by these two-dimensional flow results. Because situations that can be approximately modelled as narrow vertical plates occur in a number of practical situations, there exists a need to be able to predict heat transfer rates from such narrow plates. Attention has here been given to a plate with a uniform surface heat flux. The magnitude of the edge effects will, in general, depend on the boundary conditions existing near the edge of the plate. To examine this effect, two situations have been considered. In one, the heated plate is imbedded in a large plane adiabatic surface, the surfaces of the heated plane and the adiabatic surface being in the same plane while in the second there are plane adiabatic surfaces above and below the heated plate but the edge of the plate is directly exposed to the surrounding fluid. The flow has been assumed to be steady and laminar and it has been assumed that the fluid properties are constant except for the density change with temperature which gives rise to the buoyancy forces, this having been treated by using the Boussinesq approach. It has also been assumed that the flow is symmetrical about the vertical centre-plane of the plate. The solution has been obtained by numerically solving the full three-dimensional form of the governing equations, these equations being written in terms of dimensionless variables. Results have only been obtained for a Prandtl number of 0.7. A wide range of the other governing parameters have been considered for both edge situations and the conditions under which three dimensional flow effects can be neglected have been deduced.

Transient Convective Heat Transfer in Planar Stagnation Flows With Time-Varying Surface Heat Flux and Temperature

1992 ◽  
Vol 114 (1) ◽  
pp. 85-93 ◽  
Author(s):  
D. A. Zumbrunnen
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Steady State ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Governing Equation ◽  
Surface Heat Flux ◽  
Surface Heat ◽  
Time Varying ◽  
Rapid Transients

Impinging flows are used in a variety of applications where effective and localized heat transfer is mandated by short residence times or by space constraints, as in cooling materials moving along a conveyor or removing heat dissipated within microelectronic circuitry. A wide selection of heat transfer correlations is available for steady-state conditions. However, instantaneous heat transfer coefficients can differ significantly from steady-state values when temporal variations occur in the surface heat flux or surface temperature. Under these conditions, the temperatures of fluid layers near the surface are affected preferentially due to their proximity to the temporal variation. A theoretical model is formulated to assess the importance of a time-varying surface heat flux or temperature on convective heat transfer in a steady, planar stagnation flow. A governing equation for the transient heat transfer response is formulated analytically from the boundary layer equations for momentum and energy conservation in the fluid. Numerical solutions to the governing equation are determined for ramp and sinusoidal changes in the surface heat flux or temperature. Results indicate that the time response is chiefly governed by the velocity gradient in the free stream and to a lesser extent by the Prandtl number. Departures from steady-state Nusselt numbers are larger for more rapid transients and smaller or comparable in size to the magnitude of the imposed variation at the surface.

Influence of Space-Varying Surface Heat Flux on the Heat Transfer Due to a Moving Fluid Over a Moving Surface

2013 ◽  
Vol 135 (8) ◽  
Author(s):  
Swati Mukhopadhyay ◽  
Iswar Chandra Mondal ◽  
Kuppalapalle Vajravelu ◽  
Robert A. Van Gorder
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Heat Flux ◽  
Power Law ◽  
Surface Heat Flux ◽  
Flat Surface ◽  
Similarity Solutions ◽  
Surface Heat ◽  
Forced Convective Heat Transfer ◽  
Moving Fluid

Boundary-layer forced convective heat transfer at a moving flat surface parallel to a moving stream is presented for the case where the plate is subjected to a variable heat flux. In particular, we assume that the surface heat flux varies with spatial variable x according to a power-law rule. The similarity solutions for the problem are obtained by solving the reduced ordinary differential equations numerically, while exact solutions are provided for certain parametric values. It is noted that even in the case of prescribed surface heat flux, dual solutions exist when the surface and the fluid move in opposite directions.

scholarly journals Thermo-micropolar fluid flow along a vertical permeable plate with uniform surface heat flux in the presence of heat generation

2009 ◽  
Vol 13 (1) ◽  
pp. 23-36 ◽  
Author(s):  
Mohammad Rahman ◽  
Ibrahim Eltayeb ◽  
Mohammad Rahman
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Friction Coefficient ◽  
Skin Friction ◽  
Heat Generation ◽  
Surface Heat Flux ◽  
Micropolar Fluid ◽  
Skin Friction Coefficient ◽  
Surface Heat ◽  
Viscous Drag

A two-dimensional steady convective flow of thermo-micropolar fluid past a vertical permeable flat plate in the presence of heat generation with uniform surface heat flux has been analyzed numerically. The local similarity solutions for the flow, microrotation (angular velocity) and heat transfer characteristics are illustrated graphically for various material parameters entering into the problem. The effects of the pertinent parameters on the local skin friction coefficient, plate couple stress, and the rate of heat transfer are also calculated and displayed graphically. The results show that skin friction coefficient (viscous drag) and the rate of heat transfer (Nusselt number) in micropolar fluid are less compared to that of the Newtonian fluid.

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