D1.1 - Ultrasound array measurement system for multi-plane and multi-component flow mapping in liquid metals

Flows of metal melts are of outstanding importance for a variety of technological processes, especially for steel production, such as the continuous casting process. In recent developments, the application of magnetic fields is investigated to influence the flow in a defined way and to optimize the quality of the resulting product. Experimental flow investigations are indispensable to understand the interaction between the magnetic fields and the induced flows. The ultrasound pulse Doppler technique is appropriate for flow investigations. However, the available devices employ only a strongly limited number of transducers, which often is not sufficient for a flow mapping. In order to overcome these limitations a dual-plane, dual-component ultrasound array Doppler velocimeter for mapping of transient flow phenomena is presented. It utilizes four sensor arrays consisting of 25 single element transducers along a line of 67 mm. The system combines a spatial resolution of up to 3 mm with a temporal resolution of 30 Hz using electronic beam traversing and time division multiplex. The modular realization of the measurement system allows flexible sensor configuration, e. g. four planes can be measured with one velocity component, two planes with two components or two lines with three components. Those capabilities are demonstrated by measurements in a magnetically stirred metal melt at room temperature.