Dry calibration of a new generation local Lorentz force flowmeter

Local Lorentz force velocimetry (LFV) is a local velocity measurement technique for liquid metals. Due to the interaction between an electrically moving liquid and an applied magnetic field, eddy currents and flow-braking Lorentz forces are induced within the fluid. Due to Newtons’s third law, a force of the same magnitude acts on the source of the applied magnetic field which is in our case a permanent magnet. The magnet is connected to a new generation L2F2 that has been especially developed to record all these three force and three torque components. This sensor has already been tested at a continuous casting model with a 15 mm cubic magnet providing an insight of the 3-D velocity distribution of GaInSn near the wide face of the mold. For a better understanding of these results, especially regarding torque sensing, we propose dry experiments which consist on replacing the flowing liquid by a moving solid. In this kinematic approach, where the velocity field is already given, we are able to decrease considerably the variability and the noise of the measurements providing an accurate calibration of the system. In this paper we present the numerical results using a rotating disc made of aluminum and two different magnet systems that move across the plane of its axis of rotation.