Free convection around a vertical isothermically heated plate of finite length at large prandtl numbers

1985 ◽  
Vol 19 (5) ◽  
pp. 811-815
Author(s):  
A. A. Berezovskii ◽  
A. A. Kovkova ◽  
Yu. A. Sokovishin
Keyword(s):  
Free Convection ◽  
Finite Length ◽  
Heated Plate ◽  
Prandtl Numbers

Study of the Laminar Free-Convection Wake Above an Isothermal Vertical Plate

1973 ◽  
Vol 95 (3) ◽  
pp. 289-294 ◽  
Author(s):  
N. E. Hardwick ◽  
E. K. Levy
Keyword(s):  
Free Convection ◽  
Vertical Plate ◽  
Fluid Motion ◽  
Heated Plate ◽  
Two Dimensional ◽  
Wake Region ◽  
Hot Wire ◽  
Near Wake ◽  
Steady Laminar ◽  
Finite Difference Techniques

The steady, laminar, two-dimensional wake above a thin vertical isothermal heated plate cooled by free convection was investigated theoretically and experimentally. The system of partial differential equations governing the fluid motion and heat transfer in the vicinity of the plate and in the near wake region was formulated and solved using finite difference techniques. Using air, the temperature and velocity profiles in the wake region were measured experimentally using a laser holographic interferometer and a constant temperature hot wire anemometer.

An Experimental Investigation of Heat Transfer and Buoyancy Induced Transition from Laminar Forced Convection to Turbulent Free Convection over a Horizontal Isothermally Heated Plate

1978 ◽  
Vol 100 (3) ◽  
pp. 429-434 ◽  
Author(s):  
H. Imura ◽  
R. R. Gilpin ◽  
K. C. Cheng
Keyword(s):  
Heat Transfer ◽  
Free Convection ◽  
Forced Convection ◽  
Leading Edge ◽  
Finite Amplitude ◽  
Heated Plate ◽  
Transfer Rates ◽  
Longitudinal Vortices ◽  
Turbulent Flow Regime ◽  
Laminar Forced Convection

The flow over a horizontal isothermally heated plate at Reynolds numbers below that at which hydrodynamic instabilities exist, is characterized by a region of laminar forced convection near the leading edge, followed by the onset of longitudinal vortices and their growth to a finite amplitude and finally a transition to a turbulent flow regime. Results are presented for the temperature profiles, the thermal boundary layer thickness, and the local Nusselt number. They are used to identify the various flow regimes. It was found that the transition from laminar forced convection to turbulent convection was characterized by the parameter Grx/Rex1.5 falling in the range 100 to 300. For values of this parameter greater than 300 the heat transfer rates were independent of Reynolds number and typical of those for turbulent free convection from a horizontal surface.

Free-convection effects in the boundary layer along a vertically stretching flat surface

1992 ◽  
Vol 70 (12) ◽  
pp. 1253-1260 ◽  
Author(s):  
John E. Daskalakis
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Free Convection ◽  
Skin Friction ◽  
Flat Surface ◽  
Relaxation Method ◽  
Boussinesq Approximation ◽  
Axial Coordinate ◽  
Prandtl Numbers ◽  
Energy Equations

We assess the effects of free convection on the boundary layer formed along a flat surface stretching vertically in a quiescent fluid. The flow is laminar and incompressible, the buoyancy forces conform to the Boussinesq approximation and the surface temperature is variable. The two-point boundary value problem of the coupled momentum and energy equations is solved using a simple and accurate relaxation method that provides the general nonsimilar solution to the flow. The effect of free-convection currents on velocity and temperature profiles, skin friction, and heat transfer is studied by varying the flow Grashof and Prandtl numbers. Zero shear stress and heat-transfer rate are predicted at some axial coordinate on a surface with decreasing wall temperature. Also the skin friction is markedly modified by the buoyancy while the heat transfer at the surface is correspondingly only moderately influenced.

Development of Wall and Free Plumes Above a Heated Vertical Plate

1978 ◽  
Vol 100 (2) ◽  
pp. 184-190 ◽  
Author(s):  
E. M. Sparrow ◽  
S. V. Patankar ◽  
R. M. Abdel-Wahed
Keyword(s):  
Boundary Layer ◽  
Vertical Plate ◽  
Leading Edge ◽  
Convection Boundary Layer ◽  
Heated Plate ◽  
Adiabatic Wall ◽  
Similarity Type ◽  
Vertical Extension ◽  
Prandtl Numbers ◽  
Wall Plume

An analysis has been made to determine the successive stages of development as the natural convection boundary layer on a steadily heated vertical plate evolves into a plume. Both the wall plume and the free plume are investigated. The wall plume develops along an adiabatic wall which is the vertical extension of the heated plate. The free plume is created as the boundary layer streams away from the upper edge of the plate. Since the plate is heated on only one of its faces, the free plume is initially unsymmetric. The development of these plumes does not admit similarity-type boundary layer solutions, and numerical techniques were, therefore, employed, with results being obtained for Prandtl numbers of 0.7, 2, 5, and 10. It was found that at sufficient downstream distances both plumes attain their respective fully developed behaviors (i.e., similar profiles at successive streamwise stations). For the wall plume, the development for all Prandtl numbers is completed at a position that is about five plate lengths above the leading edge of the heated plate. The development length for the free plume for Pr = 0.7 is about the same as that for the wall plume, but about 30 plate lengths are required for the development of the free plume when Pr = 10. The fully developed free plume is symmetric.

Hydromagnetic Free Convection for High and Low Prandtl Numbers

1970 ◽  
Vol 29 (6) ◽  
pp. 1608-1618 ◽  
Author(s):  
R. S. Nanda ◽  
H. K. Mohanty
Keyword(s):  
Free Convection ◽  
Prandtl Numbers
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