An Analysis of Laminar Free and Forced Convection between Finite Vertical Parallel Plates

1973 ◽  
Vol 95 (1) ◽  
pp. 53-59 ◽  
Author(s):  
J. Quintiere ◽  
W. K. Mueller
Keyword(s):  
Heat Transfer ◽  
Forced Convection ◽  
Wall Temperature ◽  
Parallel Plates ◽  
Constant Property ◽  
Uniform Wall Temperature ◽  
Approximate Analytical Solutions ◽  
Wide Range ◽  
Free And Forced Convection ◽  
Prandtl Numbers

Approximate analytical solutions are presented for constant-property laminar free- and forced-convection flows between finite vertical parallel plates. For free convection, the thermal boundary conditions considered include the thermally symmetric channel with uniform wall temperature or step change in wall temperature and the unsymmetric channel with uniform but unequal wall temperatures. For forced convection and combined free and forced convection, the thermally symmetric and uniform thermal boundary condition is considered. Where possible, results are compared with available numerical and experimental results. Particular attention is given to heat-transfer results, which cover a wide range of Rayleigh and Prandtl numbers. For combined convection the heat-transfer results are related to the impressed pressure difference and flow rate.

On Unsteady Heat Transfer of Combined Free and Forced Convection in Circular Tubes

1963 ◽  
Vol 30 (2) ◽  
pp. 257-262 ◽  
Author(s):  
L. N. Tao
Keyword(s):  
Heat Transfer ◽  
Forced Convection ◽  
Wall Temperature ◽  
Time Variation ◽  
Circular Tube ◽  
Unsteady Heat Transfer ◽  
Transient Problem ◽  
Axial Temperature ◽  
Free And Forced Convection ◽  
Transfer Problems

The unsteady heat-transfer problems of combined free and forced convection of a fully developed laminar flow of a heat-generating fluid in a circular tube with constant axial temperature gradient at the wall are investigated. The general solution with arbitrary time-dependent pressure gradient, heat generation, and wall temperature is established by the application of the “generalized Duhamel’s theorem.” Two specific cases are then studied. The results indicate that this type of transient problem has a time-variation of an oscillatory type with decaying amplitude. This time-variation is different from that of forced convection or of combined free and forced convection with constant axial wall temperature.

Fluid-to-Fluid Conjugate Heat Transfer for a Vertical Pipe—Internal Forced Convection and External Natural Convection

1980 ◽  
Vol 102 (3) ◽  
pp. 402-407 ◽  
Author(s):  
E. M. Sparrow ◽  
M. Faghri
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Nusselt Number ◽  
Natural Convection ◽  
Forced Convection ◽  
Wall Temperature ◽  
Bulk Temperature ◽  
Vertical Pipe ◽  
Uniform Wall Temperature ◽  
Uniform Wall

An analysis is made of the interactive heat transfer problem involving forced convection flow in a vertical pipe and natural convection boundary layer flow external to the pipe. Both flows are laminar. Solutions of the conservation equations for mass, momentum, and energy were obtained numerically by an iterative scheme which deals successively with the internal and external flows. Remarkably rapid convergence was achieved by adopting a procedure whereby information is transferred between the two flows via heat transfer coefficients rather than via the wall or bulk temperatures or the heat flux. Results are presented for the axial distributions of the internal and external Nusselt numbers, of the wall temperature, and of the bulk temperature of the internal flow—all as a function of three parameters. It was found that at any (dimensionless) axial station, the pipe Nusselt number is insensitive to the parameters and is bounded between the values for uniform wall temperature and uniform wall heat flux. On the other hand, the external natural convection Nusselt number is highly sensitive to the parameters and departs substantially from the standard uniform wall temperature results.

Combined Free and Forced Convection Heat Transfer From a Heated Tube to a Transverse Air Stream

1969 ◽  
Vol 91 (3) ◽  
pp. 457-459 ◽  
Author(s):  
G. K. Sharma ◽  
S. P. Sukhatme
Keyword(s):  
Heat Transfer ◽  
Forced Convection ◽  
Convection Heat Transfer ◽  
Reynolds Numbers ◽  
Convection Heat ◽  
Heated Tube ◽  
Combined Convection ◽  
Air Stream ◽  
Wide Range ◽  
Free And Forced Convection

Heat transfer by combined free and forced convection from a heated tube to a transverse air stream has been experimentally studied over a wide range of Grashof and Reynolds numbers. The data obtained have been correlated with Gr/Re2.5 as the correlating parameter. Criteria for transition from free convection to combined convection and from combined convection to forced convection have also been obtained.

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