Weakly turbulent Rayleigh-Bénard convection in a horizontal magnetic field

MHD Rayleigh-Bénard convection was studied experimentally using a liquid metal inside a box with square horizontal cross section and aspect ratio five. Systematic flow measurements were performed by means of ultrasound Doppler velocimetry that can capture time variations of instantaneous velocity profiles. Applying a horizontal magnetic field organizes the convective motion into a flow pattern of quasi-two dimensional rolls arranged parallel to the magnetic field. If the Rayleigh number (Ra) is increased over a certain threshold Ra/Q, whereby Q is the Chandrasekhar number, the convection flow undergoes a transition to turbulence. We explore the flow structure in a weakly turbulent convection pattern by means of experiments and by means of numerical simulations.