Vortex structure and control in a lid-driven cavity with magnetic field

Ferrofluids are magnetic field-sensitive colloidal solutions of ultra-fine, single-domain superpara-magnetic nanoparticles of metallic materials. An external magnetic field can be used to regulate the magnetic nanoparticles in the ferrofluid, which permits the fluid to flow and distribute within the domain in a predetermined way. This study examines the ferrofluid flow properties in a lid-driven cavity exposed to an external magnetic field. We investigate the impact of different aspect ratios, Reynolds number, and magnetic field strength on generation of vortices and their behavior. We have simulated aspect ratios of 1, 0.5, and 2 in this investigation, using Reynolds number values of 100, 400, and 1000 and magnetic field strength of 0, 1, and 4 tesla. Our results show that the introduction of magnetic fields greatly modifies the behavior of vortex, affecting the flow stability, and vorticity patterns inside the cavity. These findings have ramifications for actuation mechanisms, drug delivery systems, and microfluidic devices. In particular, we find that the flow patterns in the cavity evolve from basic recirculation to more intricate vortex structures. The commencement of these transitions is largely dependent on the Reynolds numbers. Along the sidewalls, secondary vortices form at higher Reynolds numbers. Practical applications can benefit from the enhanced mixing provided by these sidewall vortices. Additionally, we talk about how ferrofluids might improve fluid control and manipulation in constrained geometries. The interaction of magnetism and fluid dynamics creates opportunities for new types of actuation mechanisms in which the ferrofluid flow can be steered and controlled by magnetic fields. Our research opens up new avenues for creative applications in microfluidics and other fields by providing insightful information on ferrofluid behavior.