Numerical and experimental investigation of heat transfer process in electromagnetically driven flow within a vacuum induction furnace

The paper presents an advanced numerical study of the operation of the vacuum induction furnace. The two-way coupling of electromagnetic and fluid dynamics fields was developed to accurately predict the temperature distribution within the crucible melt and walls that were simplified to two-dimensional axisymmetric domain. To define the heat transfer inside the charge, both radiative and convective heat fluxes were taken into consideration. To solve electromagnetic problem, a set of differential Maxwell equations with appropriate boundary conditions were specified. Numerical simulations were performed for several cases to examine the influence of inductor position and power on the coupled processes inside the crucible. The proposed mathematical model was validated against experimental data obtained in the real vacuum induction furnace. The measurements were performed using non-intrusive contactless methods with infrared and high-speed cameras. Validation of free surface showed clearly that numerical results were within the standard deviation for two variants of coil input power. The obtained results of heat transfer within the crucible indicated importance of the radiative heat transfer, especially that of the charge. Moreover, the proposed model showed a good agreement in terms of charge temperature and temperature profile on the crucible wall with a relative error lower than 5%.