摘要

An Archimedean helical magnetic field was constructed upon small permanent magnet units and the flow pattern of molten metal driven by helical magnetic field was researched. First, the distribution of helical magnetic field was analyzed by experimental measurements and numerical simulations: helical magnetic field could be considered as the superposition of rotating magnetic field and traveling magnetic field; second, the results of experimental measurement and numerical simulation show that the distribution and strength of magnetic field between the ideal helical magnets and actual magnets constructed upon permanent magnet units is consistent; finally, the velocity of molten metal flow driven by permanent magnet helical magnetic field was measured by Ultrosonic Doppler Velocimetry (UDV) quantitatively and the results indicate that the permanent magnet helical magnetic field can drive molten metal in a flow pattern of a global helical flow under certain experimental parameters.