F1 Heat Transfer by Free Convection: Fundamentals

1 Formulation of the Problem

Free convection refers to the fluid flow which is driven by a spatially nonuniform distribution of density [1]. The nonuniformity of density can be either a result of inhomogeneous temperature distribution or nonuniform concentration of an admixture such as salt concentration in seawater. The present overview is exclusively devoted to free convection due to temperature differences.

The general formulation of heat transfer problems as relevant to practical applications is shown in Fig. 1, where Fig. 1a is for external flows and Fig. 1b is for internal flows. For external flows the heat transfer problem consists in computing the total heat flow $\dot{Q}$ from a hot body to the surrounding fluid for given values of the uniform surface temperature T _S of the hot body and of the temperature of the fluid T _∞ far away from the body. For internal flows the heat transfer problem consists in computing the total heat flow $\dot{Q}$for given values of the uniform...