Control of the gallium melting rate with a non-uniform magnetic field: Experimental and numerical study

The presence of magnetic fields in the metal melting process enables control over the phase-change in energy storage systems. In this work, the melting process of gallium in the presence of a static non-uniform magnetic field is studied experimentally and numerically. The experimental setup consists of a prismatic cavity with dimensions of 55 × 50 × 50 mm, filled with gallium, initially solid at 29 ° C . A horizontal temperature difference with values of 8, 9.5, and 11 ° C is set on two parallel faces. A permanent magnet, placed on the top wall, generates a non-uniform magnetic field. The main magnetic field component is aligned with gravity and perpendicular to the imposed temperature difference. Studies are conducted both with and without the magnetic field. Experimentally, ultrasonic Doppler techniques characterize the solid–liquid interface and velocity profiles. Additionally, a three-dimensional numerical study was conducted using ANSYS Fluent software. The experimental and numerical results for the magnetic field distribution, solid–liquid interface, and velocity profiles are consistent and demonstrate that the externally imposed magnetic field slows down the fluid flow and the melting rate by up to 38% and 22%, respectively. It also shows that the solid–liquid interface becomes flatter under the magnetic field. • The magnetic field slows down the melting rate by up to 22%. • Solid–liquid interface is flatter when the magnetic field is applied. • The Nusselt number decreases with the magnetic field.