A Review of Recent Progress in Heat Transfer

Abstract

The state of knowledge of heat transfer in relation to mechanical engineering problems was summarized by Professor Dalby in a paper before the Institution in 1909. The present paper discusses the growth of knowledge during the past thirty years, and the ever-expanding fields of application. Complete rationalization is still not possible, but dimensional methods similar to those used in ship and aircraft design are being applied more and more generally to heat transfer problems. By their aid the practical range of any set of data may be greatly widened. For example, experiments made under pressure on surfaces only a few inches high may be used to deduce the heat transfer for surfaces several feet high at atmospheric pressure; or experiments made in gases may be used to predict the heat transfer in liquids. Selected cases dealt with in the paper are: forced convection for banks of tubes and beds of broken solids, and the relation between heat transfer and friction; natural convection from vertical and horizontal surfaces and across fluid layers; heat transfer in the drop and film condensation of steam, and in film and nucleate boiling; evaporation and its relation to convection; emissive powers of surfaces for radiation; and radiation from non-luminous gases.