Visualization of Rayleigh-benard convection in liquid metals

摘要

A layer of liquid gallium, laterally confined in a small cavity, is heated from below and cooled from above. Real-time radioscopy is used for density field visualizations. For the first time the onset of convection in an opaque liquid metal is determined from direct optical visualizations. For slightly supercritical Rayleigh numbers the wave numbers are measured and compared to linear stability analysis. Good agreement between theory and experiments is achieved.