The University of Exeter’s College of Engineering, Mathematics and Physical Sciences is inviting applications for a PhD studentship funded by the Science and Technology Facilities Council (STFC) to commence in September 2019 or as soon as possible thereafter. This research project is in competition with one other studentship project. One studentship will be awarded to the best applicant for either project. For eligible students the studentship will cover UK/EU tuition fees plus an annual tax-free stipend of at least £14,777 for 3.5 years full-time, or pro rata for part-time study. The student would be based in the Centre for Geophysical and Astrophysical Fluid Dynamics which is part of the Department of Mathematics in the College of Engineering, Mathematics and Physical Sciences at the Streatham Campus in Exeter.
Magnetic fluids of the Earth, Sun, stars and galaxies are generated by the motion of electrically conducting fluid, for example hydrogen plasma in the case of the Sun, liquid metal for the Earth. The project concerns a fundamental process in the interaction of magnetic field and fluid called flux expulsion, where field is expelled from regions of closed streamlines, for example a fluid vortex. This process was first identified by Nigel Weiss in the 1960s, but it was only recently that studies included the magnetic field feedback on the flow through the Lorentz force, e.g. Gilbert, Mason and Tobias (2016). The goal of the project is to study flux expulsion in a thin layer using the equations of shallow water magnetohydrodynamics (MHD) where the fluid motion is coupled to gravity waves. Such models are relevant to the solar tachocline and other systems where the fluid is stratified. The study would initially use numerical simulations in periodic geometry, but the goal would be also to develop scaling laws and analytical models.
A.D. Gilbert, J. Mason & S.M. Tobias 2016 Flux expulsion with dynamics, J. Fluid Mech. 791, 568-58
For students who meet the residency requirements outlined by Research Councils UK this award provides annual funding to cover UK/EU tuition fees and a tax-free stipend. For students who pay UK/EU tuition fees the award will cover the tuition fees in full, plus at least £14,777 per year tax-free stipend. Applicants who are classed as international for tuition fee purposes are not eligible for funding. EU applicants who do not meet the residency requirements may still be eligible for a fees-only award.