The Coupling of Conduction With Laminar Natural Convection From a Vertical Flat Plate With Arbitrary Surface Heating

1970 ◽  
Vol 92 (3) ◽  
pp. 528-535 ◽  
Author(s):  
A. E. Zinnes
Keyword(s):  
Boundary Layer ◽  
Natural Convection ◽  
Flat Plate ◽  
Finite Thickness ◽  
Heat Conducting ◽  
Constant Property ◽  
Difference Form ◽  
Laminar Natural Convection ◽  
Degree Of Coupling ◽  
Experimental Corroboration

A method has been developed for coupling conduction in a solid with natural convection in a surrounding fluid. The problem investigated is that of steady, constant-property, two-dimensional, laminar natural convection from a vertical, heat-conducting flat plate of finite thickness with an arbitrary heating distribution in its surface. Using this method it is possible to predict the variation of temperature in the plate and the velocity and temperature profiles in the boundary layer as a function of the heating distribution and the thermal properties of the plate and fluid. The equations for conduction in the plate and convection in the boundary layer are written in finite difference form, coupled through the common heat flux at the plate-fluid interface, and solved numerically by an iterative technique. Experimental corroboration of the numerical results is provided by measuring temperatures, both with thermocouples and a laser holographic interferometer, along ceramic and glass plates heated by thin film resistance heating elements vacuum deposited on their surface. The results indicate that the degree of coupling between conduction in the plate and natural convection in the fluid is greatly influenced by the plate-fluid conductivity ratio.

NATURAL CONVECTION BOUNDARY LAYER FLOW PAST A FLAT PLATE OF FINITE DIMENSIONS

2012 ◽  
Vol 15 (6) ◽  
pp. 585-593
Author(s):  
M. Jana ◽  
S. Das ◽  
S. L. Maji ◽  
Rabindra N. Jana ◽  
S. K. Ghosh
Keyword(s):  
Boundary Layer ◽  
Natural Convection ◽  
Flat Plate ◽  
Boundary Layer Flow ◽  
Convection Boundary Layer ◽  
Flow Past ◽  
Convection Boundary ◽  
Layer Flow

The Effect of Partitions on the Laminar Natural Convection in a Square Cavity

2008 ◽  
Author(s):  
Wenjiang Wu ◽  
Chan Y. Ching
Keyword(s):  
Boundary Layer ◽  
Natural Convection ◽  
Secondary Flow ◽  
Rear Surface ◽  
Vertical Wall ◽  
Convection Flow ◽  
Square Cavity ◽  
Flow Circulation ◽  
Laminar Natural Convection ◽  
Layer Flow

The effect of a partition on the laminar natural convection flow in an air-filled square cavity driven by a temperature difference across the vertical walls was investigated experimentally. Two partitions with non-dimensional heights of 0.0625 and 0.125 was attached either to the upper half of the heated vertical wall or the top wall at different locations. The experiments were performed for a global Grashof number of approximately 1.24×108 and non-dimensional top wall temperatures of approximately 0.48 to 2.28. At the higher top wall temperatures, a secondary flow circulation region formed between the partition attached to the top wall and the heated vertical wall of the cavity. This secondary flow circulation region was sensitive to the location and height of the partition, in addition to the top wall temperature of the cavity. The secondary flow circulation region moved the location where the upward boundary layer flow along the heated vertical wall turned over to be further away from the top wall, than in the cavity without the partition. A thermal boundary layer was observed to move along the rear surface of the partition attached to the top wall. In the region close to the top wall, the partitions caused the non-dimensional temperature outside of the boundary layer and the local Nusselt number along the heated vertical wall to be different from that in the cavity without the partition. There were no significant effects of the partition on the flow and heat transfer characteristics in the lower half of the cavity.

Heat and mass transfer from a flat plate of finite thickness to a boundary layer flow with transpiration

1997 ◽  
Vol 38 (10-13) ◽  
pp. 1209-1218 ◽  
Author(s):  
Shigeru Mori ◽  
Mikio Kumita ◽  
Tohru Takahashi ◽  
Akira Tanimoto ◽  
Mikio Sakakibara
Keyword(s):  
Boundary Layer ◽  
Mass Transfer ◽  
Flat Plate ◽  
Heat And Mass Transfer ◽  
Boundary Layer Flow ◽  
Finite Thickness ◽  
Layer Flow

Mass transfer in laminar flow

1954 ◽  
Vol 221 (1144) ◽  
pp. 78-99 ◽  
Keyword(s):  
Boundary Layer ◽  
Mass Transfer ◽  
Natural Convection ◽  
Laminar Flow ◽  
Flat Plate ◽  
The Body ◽  
Liquid Fuels ◽  
Fluid Stream ◽  
Mean Values ◽  
Fluid Properties

Starting from the differential equation of mass transfer in laminar flow and the appropriate boundary condition, expressions are derived for the rate of mass transfer from ( a ) a flat plate in a longitudinal fluid stream, ( b ) a vertical flat plate by natural convection, ( c ) the forward stagnation point of a sphere in a fluid stream. Only outward mass transfer is considered; this corresponds to blowing outwards from the plate at a rate inversely proportional to the boundary-layer thickness. The Kármán-Pohlhausen-Kroujiline method is used. Where appropriate the Prandtl or Schmidt number has been taken as 0⋅71. The calculations are valid for all mass-transfer processes for which a single diffusion coefficient can be ascribed to the diffusing property, but are particularly relevant to the combustion of liquid fuels, for which the outward mass-transfer rates are so high that important deviations occur from boundary-layer profiles without mass transfer. Despite the great temperature variations present in boundary layers with combustion, mean values for the fluid properties are assumed. In the case of natural convection, it is assumed that the body forces on the fluid in the boundary layer are everywhere zero; this leads to a less serious over-estimate of the buoyancy than the usual assumptions which are valid only for small temperature differences.

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