Influence of Coil Angle Arrangement on Dynamic Deformation and Stability of Molten Droplet in Electromagnetic Levitation System

摘要

This work presents a transient simulation of electromagnetically levitated deformed droplet based on Arbitrary Lagrangian-Eulerian method. The magnetic, flow, temperature fields as well as free surface deformation of a molten aluminum droplet are coupled to investigate the influence of coil angle arrangement on dynamic deformation and stability of the droplet under terrestrial conditions. Our results confirm that the Arbitrary Lagrangian-Eulerian method can trace the interface of molten droplet more precisely and the calculation of surface effect is more reliable than that of VOF method. Simulation results show that the electromagnetically levitated molten droplet tends to oscillate in vertical direction and the sphere shape deforms largely at the very beginning of simulation. The dynamic deformation of the molten droplet is small during vertical oscillations since the density of aluminum is small. With the increasing of coil angle, the maximum velocity inside droplet decreases gradually and an over 10% difference is observed comparing with 0 and 30 degree coil angles. At the same time, the temperature of droplet declines significantly with the increasing of coil angles, which is of potential interest for temperature control improvement and undercooling processes in electromagnetic device. The deformation of droplet is observed to be most serious with a coil angle of 12 degree, which should be avoided in future coil design for the purpose of stable levitation of massive materials.