A STUDY OF NATURAL-CONVECTION IN A ROTATING ENCLOSURE

The local and mean natural convection heat transfer characteristics an d flow fields were studied experimentally and numerically in an air-fi lled, differentially heated enclosure with a cross-sectional aspect ra tio of one. The enclosure is rotated above its longitudinal horizontal axis. A Mach-Zehnder interferometer was employed to reveal the entire temperature field, which enable the measurement of the local and mean Nusselt numbers at the hot and cold surfaces. Laser sheet flow visual ization was employed to observe the flow field. The result showed that the Coriolis and centrifugal buoyancy forces arising from rotation ha ve a remarkable influence on the local heat transfer when compared wit h the nonrotating results. Local heat fluxes were obtained as a functi on of Taylor (Ta less-than-or-equal-to 4 x 10(5)) and Rayleigh numbers (10(4) < Ra less-than-or-equal-to 3 x 10(5)), at different angular po sitions of the enclosure. In addition, a series of interferograms, str eam function and isotherm plots demonstrated the strong effect of rota tion on the flow field and heat transfer. A correlation of Nusselt num ber as a function of Taylor and Rayleigh numbers is presented.