Flux expulsion in shallow water magnetohydrodynamics

地球、太阳、恒星和星系的磁流体是由导电流体的运动产生的，例如太阳的氢等离子体，地球的液态金属。该项目涉及磁场和流体相互作用的一个基本过程，称为通量驱逐，其中磁场从封闭流线区域驱逐，例如流体漩涡。这一过程最早由奈杰尔·韦斯（Nigel Weiss）在20世纪60年代发现，但直到最近，研究才包括通过洛伦兹力对流动的磁场反馈，例如Gilbert， Mason和Tobias（2016）。该项目的目标是利用流体运动与重力波耦合的浅水磁流体动力学（MHD）方程研究薄层中的通量排出。这种模式与太阳速斜和其他流体分层的系统有关。这项研究最初将在周期几何中使用数值模拟，但目标也将是发展比例定律和分析模型。

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.