307 超音波による液体ガリウム層内対流運動の可視化(S42-1 流れの可視化実験解析(1),S42 流れの可視化実験解析)  [in Japanese] 307 Ultrasonic Visualization of Convection Motion in Liquid Gallium Layer  [in Japanese]

Natural convection induced by a vertical temperature gradient in a slab shape container filled with liquid Gallium is investigated experimentally. An instantaneous velocity profile in the fluid layer was measured using UVP (Ultrasonic Velocity Profiler), which can be used for opaque fluid such as liquid metal. The results represent a convective flow pattern and its temporal fluctuation. There are some situations, where 2, 3 or 4 convection rolls appear, on the visualized convective motion. A variation of the number of rolls is shown by spatio-temporal velocity map. Simultaneous velocity profile measurement using two ultrasonic transuducers indicates axial fluctutation of the rolls.