FLOW REGIMES IN A SHALLOW ROTATING CYLINDRICAL ANNULUS WITH TEMPERATURE GRADIENTS IMPOSED ON THE HORIZONTAL BOUNDARIES.

The fluid flow types observed in a new rotating cylindrical annulus configuration are presented in regime diagrams. This new annulus has radial temperature gradients imposed on plane, horizontal, thermally conducting endwalls and the cylindrical sidewalls are insulators. This configuration is to be contrasted with the classical cylindrical annulus which has differentially heated conducting sidewalls and insulating endwalls. Unlike the classical annulus the new configuration permits a measure of control over the internal vertical temperature gradient. As well as the axisymmetric flow and non-axisymmetric baroclinic wave flow which occur in the classical annulus, two additional non-axisymmetric flow types, boundary-layer thermal convection and deep thermal convection, are observed in the new annulus. Three flow regime diagrams for three different values of the imposed vertical temperature difference are presented.