Ultrasonic flow measurements in electrically magnetized Couette-Taylor and related flows

Studying magnetized Couette-Taylor experiments requires an interaction of the flow and magnetic field. So a good conductive liquid is needed. Therefore liquid metal is the best choice in laboratory experiments. Liquid metals are opaque and optical measurement techniques are not suitable. The Ultrasound Doppler Velocimetry (UDV) is a non-intrusive technique to measure velocities of liquid flows. Because of the ability to work in opaque fluids and to deliver complete velocity profiles in real time it is very attractive for liquid metal applications.
For instance the MRI comes up at magnetic fields which are generated by strong currents up to 20 kA in the modified PROMISE facility. Other related experiments at our multipurpose magnetic field system (MULTIMAG) using alternating magnetic fields to influence or drive the flow. Magnetizing a flow due to electrical current generates always electromagnetic indifferences (EMI) on the weak receiver signal at the UDV instrument.
In this poster we present solutions to reduce EMI and present some special results from the magnetorotational instability (MRI), discovered by Velikhov in 1959 and a wind in a thermal and electromagnetic driven flow.