Lorentz Force Velocimetry for Local Velocity Measurement

摘要

Standard flow measurement techniques fail for liquid metals due to their high temperatures,opaqueness and aggressiveness.However,recent developments in the measurement of volumetric fluxes of industrially relevant metal melts have been made.One of these methods,Lorentz Force Velocimetry(LFV)is based on the measurement of Lorentz forces generated when an electrically conducting fluid moves through a magnetic field.Our aim is to extend the working range of this method to the measurement of local flow velocities.To resolve local velocity fluctuations we reduce the size of the permanent magnet that produces the magnetic field.We use the fundamental setup of a square duct filled with the eutectic alloy GaInSn and having a cross-section of 5 cm by 5 cm.The magnet cube employed has an edge length of 1 cm.For this setup,we investigate both experimentally and numerically the interaction between the liquid metal flow and the non-uniform magnetic field.The results help in understanding the effect of flow dynamics on the total Lorentz force.