Inhibiting bulging deformation of liquid metal free surface by magnetic pressure

A new method was presented to inhibit bulging deformation and fluctuation of free surface by magnetic pressure. A research combined with numerical and experimental methods was conducted to investigate the feasibility and inhibition efficiency. The parameters including magnetic flux density, frequency and action area of magnetic pressure were analyzed. The results show that the method is feasible, and the bulged free surface is fully inhibited by the proper magnetic pressure. The inhibition efficiency increases as the increase in magnetic flux density and frequency, which shows a linear relationship with the magnetic flux density. The frequency has a great influence on the inhibition efficiency when the frequency is changed from 0.15 to 5.00 kHz. However, the frequency more than 5.00 kHz has little influence on the inhibition efficiency and is recommended in application process. When the ratio of the action area to the area of bulged free surface is 0.8, the best inhibition is achieved. However, when the ratio is more than 1.2, a distinct W-shaped free surface is observed. The surficial and internal flow is strengthened with proper magnetic pressure imposed. Moreover, under the action of magnetic pressure, the fluctuation amplitude of free surface decreases from 4.0 to 1.2 mm and the main fluctuation with frequency of 2.34 Hz is dispersed into several minor fluctuations with frequency of 0.4–4.3 Hz.