Development of the flow field visualization technique for thermocapillary convection of low Prandtl number fluid(2)

In the observation of thermocapillary flow using a molten metal which is an opaque low Prandtl number fluid, the internal flow pattern has to be estimated from the fluctuation pattern of the surface temperature. In order to obtain the internal flow pattern directly, the visualization technique using an ultrasonic wave has been developed. The position of a tracer can be detected by small array transducer, and the internal flow pattern can be visualized from dynamic position change of the tracers. The tracer and signal processing equipment which is used for an actual flow examination were manufactured, and these were checked satisfying a required function by the test. Moreover, the numerical simulation was performed to verify the capability of this system.