Experimental study of unsteady thermal convection in heated rotating inclined cylinders

An experimental study through temperature measurements was conducted to inv estigate the thermal characteristics induced by the interaction between the thermal buoyancy and rotation-induced Coriolis force and centrifugal force in an air-filled heated inclined cylinder rotating about its axis. Results were obtained for the following ranges of the governing groups: thermal Ra yleigh number Ra = 2.3 x 10(6) and 4.6 x 10(6), Taylor number 0 less than o r equal to Ta less than or equal to 2.2 x 10(10), rotational Rayleigh numbe r 0 less than or equal to Ra Omega less than or equal to 5.9 x 10(8) and in clined angle 0 less than or equal to Psi less than or equal to 90 degrees. The experimental data suggested that when the cylinder is stationary, the t hermal buoyancy driven flow is random oscillation at small amplitude after initial transient for inclined angle Psi < 60 degrees. Rotating the cylinde r was found to destabilize the temperature held when the rotation speed Ome ga is less than 30 rpm and to stabilize it when the Omega exceeds 30 rpm. A dditionally, the distributions of time-average temperature theta(av) in the Z-direction for various inclined angles become widely separate only at low rotation rates, Omega < 60 rpm. (C) 2000 Elsevier Science Ltd. All rights reserved.