HEAT-TRANSFER IN ROTATING CYLINDRICAL CAVITIES

Nusselt numbers are measured on the heated disc of a rotating cylindrical cavity, with either an axial throughflow or a radial outflow of coolant, over a range of gap ratios, 0. 13 less than equivalent to G less than equivalent to 0. 4, flow rates up to Re//z approximately equals 1. 8 multiplied by 10**5, rotational speeds up to Re// phi approximately equals 2. 5 multiplied by 10**6, and Grashof numbers up to Gr approximately equals 1. 7 multiplied by 10**1**2. For the axial throughflow case, dramatic increases in the values of local Nusselt numbers are observed at certain Rossby numbers; these increases are consistent with the vortex breakdown observed on a separate, isothermal laser Doppler anemometry (L. D. A. ) rig. For the radial outflow case, the mean Nusselt numbers show three separate regimes which depend on Re//z and Re// phi but are only weakly affected by G.