Velocity measurements in metallic melts: New developments and applications

In processes involving electrically conducting liquids, the application of an external magnetic field offers efficient opportunities for a contactless flow control and fluid handling. However, for a well-aimed optimisation of the flow structure local information about flow quantities like velocity, pressure, temperature, concentration or void fraction are necessary. In case of liquid metals the choice of a suitable measuring technique is a crucial problem, because the user is confronted not only with the opaqueness but also with high temperatures as well as a strong chemical reactivity of the fluid against many materials. Therefore, measuring techniques well-known from ordinary hydrodynamics generally fail for liquid metal applications. As a consequence, no commercial measuring systems are available for liquid metal applications.
During the last years experimental activities of FZR were focussed on the development and qualification of techniques to measure the velocity in liquid metal flows. Various liquid metal model experiments with various liquid melts at different temperatures have been performed to test and evaluate local sensors as well as integral methods.