Analysis on the characteristics of pulsed electromagnetic force and the fluctuation behavior of molten metal free surface under pulsed magnetic field

A self-made line laser liquid level measurement system was used to measure the fluctuation of molten metal free surface under pulsed magnetic field. The electromagnetic characteristics of pulsed electromagnetic force were mathematically analyzed. Results showed that the electromagnetic force presents oscillatory attenuation during a single pulse period. The electromagnetic force was composed of turning force f t u r n and non-turning force f n o n t u r n . The direction of f t u r n was always consistent with the melt circumferential direction, which turned the f n o n t u r n consisted of electromagnetic pull and push forces, which caused the melt to oscillate. Under the pulsed magnetic field, the free surface formed a meniscus with a high middle, low side structure. With increased pulsed field intensity, the center surface of molten melt had an oscillation of ±3.52 mm at 0.187 T. The wave power density had only two spectral peaks (at 0.60 and 3.36 Hz) without a magnetic field. Under pulsed magnetic field, four spectral peaks were found at 0.40, 3.00, 6.50 and 13.00 Hz.