Transitions between turbulent states in rotating Rayleigh-Bénard convection.
Weakly rotating turbulent Rayleigh-Bénard convection was studied experimentally and numerically. With increasing rotation and large enough Rayleigh number a supercritical bifurcation from a turbulent state with nearly rotation-independent heat transport to another with enhanced heat transfer is observed at a critical inverse Rossby number 1/Roc approximately 0.4. The strength of the large-scale convection roll is either enhanced or essentially unmodified depending on parameters for 1/Ro<1/Roc, but the strength increasingly diminishes beyond 1/Roc where it competes with Ekman vortices that cause vertical fluid transport and thus heat-transfer enhancement.
Stevens
Richard J A M
RJ
Department of Science and Technology, Impact Institute, and J.M. Burgers Center for Fluid Dynamics, University of Twente, Post Office Box 217, 7500 AE Enschede, The Netherlands.
Zhong
Jin-Qiang
JQ
Clercx
Herman J H
HJ
Ahlers
Guenter
G
Lohse
Detlef
D