Axisymmetric Bubble Growth and Detachment Subject to Inhomogeneous Magnetic Fields in Microgravity*

Understanding interfacial flows in microgravity is essential for space technologies such as water electrolysis or boiling. The use of magnetic polarization forces has been recently proposed to control bubble flows, whose magnetic susceptibility may be increased by employing ferrofluids. This paper introduces a numerical interface-tracking model addressing the growth and detachment of axisymmetric gas bubbles when subject to inhomogeneous magnetic fields in microgravity. A fully coupled ferrohydrodynamic framework of analysis is implemented using an efficient monolithic approach and second-order finite differences. The equilibrium, global stability, and modal response of axisymmetric bubbles within ferrofluids are studied. In particular, the shape and departure volume of the bubble under different fluid-magnetic configurations is addressed, offering key insights into this problem and paving the path for the development of novel space applications.