Ultrasonic flow measurements in a 1:6 downscaled water mockup of the DRESDYN dynamo experiment

The project DRESDYN (DREsden Sodium facility for DYNamo and thermohydraulic studies) conducted at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) provides a platform for a variety of liquid sodium experiments. Most ambitious experiment will be a precession driven dynamo experiment which consists of a large cylindrical cavity filled with liquid sodium that will simultaneously rotate around two axis. The experiment is motivated by the idea of a precession-driven flow as a complementary energy source for the geodynamo or the ancient lunar dynamo. The detailed knowledge of the flow structure in the precessing cylindrical vessel is of key importance for the prediction of the dynamo action. My presentation addresses experimental examinations with ultrasonic Doppler velocimetry in the low Reynolds region to validate numerical simulations.