Simple theoretical and experimental study of convection with some geophysical applications and analogies

The paper considers a plane horizontal liquid layer into which heat is introduced, and an exact expression obtained within the Boussinesq approximation for the convection efficiency in transforming the rate of heat supplied into the generation of kinetic energy. Using laboratory produced estimates of convection efficiency, values of the rms velocity of convective motions and their time scale tau are obtained for conditions where viscocity is important. Dimensionless convection equations normalized by these scales show the existence of thermal boundary layers and of almost isothermal regions within the bulk of the fluid. Experiments were made to measure velocity of convective motions and tau for convection in water which show that a smooth transition region exists from the viscous convection conditions to the more fully-developed turbulent one. Density convection is considered which is produced by the separation of a medium into light and heavy fractions, and some general properties of forced flows, convection, turbulence, and atmospheric circulation are examined.