Dynamics of Argon Gas Bubbles Rising in Liquid Steel in the Presence of Transverse Magnetic Field

TL;DR

This study numerically investigates how a transverse magnetic field influences the dynamics, shape, and flow structures of rising Argon bubbles in molten steel, revealing more organized flow patterns under magnetic influence.

Contribution

It introduces a volume of fluid method combined with a sharp surface force approach to accurately simulate bubble behavior in liquid metal under magnetic fields, advancing understanding of magnetohydrodynamic effects.

Findings

Magnetic field organizes and elongates flow structures behind bubbles.

Bubbles exhibit more stable and streamlined paths with magnetic influence.

Flow complexity increases without magnetic field.

Abstract

Bubbly flows are present in various industrial processes including metallurgical processes in which gas bubbles are injected at the bottom of bulk liquid metal to stir the liquid metal and homogenize the metal. Understanding the motion of such bubbles is essential, as it has been shown that bubble flotation can remove inclusions. In this work, we have numerically studied three-dimensional dynamics of a pair of inline Argon bubbles rising in molten steel under the influence of a transverse magnetic field. We have explored the effects of two transverse magnetic field strengths (Bx = 0 and 0.2 T). The bubbles' motion and transient rise velocities are compared under different magnetic fields. The shape deformations and path of the bubbles are discussed. The flow structures behind the bubbles are analyzed. We found that structures are more organized and elongated under a magnetic field, whereas it is complex and intertwined when the magnetic field is not included. We have used a geometry construction-based volume of fluid (VOF) method to track interface, maintain mass balance and estimate the interface curvature. Additionally, we have incorporated a Sharp Surface Force Method (SSF) for surface tension forces. The algorithm is able to minimize the spurious velocities.