High Frequency Magnetohydrodynamic Calculations in COMSOL
In many metallurgical processes metals are (heated and) stirred by an oscillating external magnetic field. The magnetic field induces electric currents in the metal and the currents interact with the magnetic field to create a force, the Lorentz force. For high frequencies induction only takes place in an electromagnetic boundary layer due to the skin effect and the force is confined within this limited region.
The Lorentz force will influence both pressure and the flow in the metal. The conservative part of the force changes the pressure of the fluid and modifies its free surface, while the rotational part generates fluid flow. In most industrial processes the flow is turbulent and numerical models are required to calculate the fluid motion.