Transitions near the onset of low Prandtl-number rotating magnetoconvection

Abstract

We investigate the onset of convective instability and subsequent transitions near it in Rayleigh-Bénard convection (RBC) of electrically conducting low Prandtl-number (Pr) fluids in the simultaneous presence of rotation about the vertical axis and external uniform horizontal magnetic field with free-slip boundary conditions. Both three dimensional direct numerical simulations (DNS) and low dimensional modeling of the system have been performed for the investigation. DNS results show a plethora of patterns near the onset of convection for weak magnetic field. Most interestingly, the Nusselt number (Nu) computed from the DNS data for relatively stronger magnetic field shows a sharp jump at the onset, indicating substantial enhancement of the convective heat transfer. The origin of these flow patterns, as well as the reason for a notable increase of heat transfer near the onset of convection, are then explained using low dimensional models constructed from DNS data.

arXiv comment31 pages, 20 figures, Submitted to journal

References in corpus (10)

• Large scale dynamics in turbulent Rayleigh-Benard convection
• Interdependent networks: Reducing the coupling strength leads to a change from a first to second order percolation transition
• Subcritical thermal convection of liquid metals in a rapidly rotating sphere
• Square patterns in Rayleigh-Benard convection with rotation about a vertical axis
• Imperfect Homoclinic Bifurcations
• Rayleigh-Bénard convection with uniform vertical magnetic field
• Role of uniform horizontal magnetic field on convective flow
• Pattern dynamics near homoclinic bifurcation in Rayleigh-Bénard convection
• A model for Rayleigh-Bénard magnetoconvection
• Zero Prandtl-number rotating magnetoconvection