Mechanism of Convective Heat Transfer and its Role in Gas Turbines *

Abstract

The fundamental dependence of convective heat transfer on the pattern of fluid flow is first stated, and this is followed by an elementary presentation, illustrated by examples of the behaviour of models, of the governing principles of fluid dynamics, particularly those concerning the boundary layer. The resultant relative levels of heat transfer from various surfaces are then discussed, together with the effect of different types of fluid. With these fundamental considerations established, an analysis is made of the economics of different types and arrangements of heat exchanger. Finally, methods of turbine-blade cooling are considered from estimates of the heat-transfer pattern round the surface of the blade.