Viscous and inviscid nonlinear dynamics on an axisymmetric ferrofluid jet

• Main Author: Cornish, Michael
• Format: Dissertation
• Language: English
• Published: Imperial College London 2018
• DOI: 10.25560/75535

In this thesis the dynamical properties of an axisymmetric ferrofluid jet are investigated. The flow is subject to the Rayleigh-Plateau instability. However, the ferrofluid is centred on a current carrying wire which produces an azimuthal magnetic field. Consequently, a super-critical magnetic field stabilises perturbations about the perfect cylinder solution but is unstable otherwise. The linearly stable regime is primarily investigated in the inviscid limit where long wave dynamics produce solitary wave structures. The dynamics of the ferrofluid are considered when either surrounded by a gas or a non-conducting fluid. The linearly unstable regime is investigated in the inviscid single-fluid and two-fluid regimes as well as in the viscous regime. In particular, the Kelvin-Helmholtz instability is investigated. Nonlinear dynamics and comparison with experimental findings are considered throughout all regimes. The nonlinear solitary wave structures show good comparison to both the theoretical and experimental literature. The nonlinear viscous regime produces static droplet chains that align with experimental findings in the literature. The final static state solutions are investigated numerically as well.