Publisher Summary The first part of the chapter focuses on determining equations for the local and mean rate of laminar heat transfer, which are approximately valid for different geometries By use of these equations, several new correlations are obtained for various laminar heat transfer problems, and the results compared with experiments The problems considered involve heat transfer (1) from a cylinder, (2) from a sphere, (3) between concentric cylinders, (4) between concentric and eccentric spheres, (5) between vertical plates, and (6) from a nonisothermal vertical plate Attention is then turned to turbulent free convection heat transfer where the heat transfer from inclined plates and between differentially heated plates is considered A method of solving problems involving both laminar and turbulent convection is then outlined The criterion developed for the regions of applicability of the laminar and turbulent equations is shown to accurately predict the experimentally determined onset of instability of the laminar flow for free convection from an isolated plate A recommendation is then made for correlating heat transfer results in a clearer and more convenient way

A General Method of Obtaining Approximate Solutions to Laminar and Turbulent Free Convection Problems

Experiments are carried out to establish the relationship between the nature of the flow instability and the inclination angle of the plate. The angular dependence of the Rayleigh number characterizing the onset of instability is also determined. An electrochemical flow visualization technique is utilized to expose the patterns of fluid motion. It is found that for inclination angles of less than 14° (relative to the vertical), waves are the mode of instability. On the other hand, for inclination angles in excess of 17°, the instability is characterized by longitudinal vortices. The range between 14° and 17° is a zone of continuous transition, with the two modes of instability co-existing.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022112070001416

On the instability of natural convection flow on inclined plates

On the stability of natural convection boundary layer flow over horizontal and slightly inclined surfaces

An experimental investigation of natural convection flow on an inclined surface

Wave instability of mixed convection flow over a horizontal flat plate

The results of an experimental study of the stability of boundary layer free convection from an inclined plane surface are presented. In particular, the relative contributions of hydrodynamic and thermal effects are investigated. It is demonstrated that thermal effects, through surface inclinations, are increasingly significant as the surface departs further from the vertical position and that positive and negative inclinations do not produce equal and opposite effects.

G. R. Pond

Papers

A study of instability in free convection from an inclined plate