Applied Mathematics Research Centre, Coventry University, Priory Street, Coventry CV1 5FB, United Kingdom.
Phys Rev Lett. 2010 Jan 22;104(3):034502. doi: 10.1103/PhysRevLett.104.034502. Epub 2010 Jan 21.
We characterize experimentally how three dimensionality appears in wall-bounded magnetohydrodynamic flows. Our analysis of the breakdown of a square array of vortices in a cubic container singles out two mechanisms: first, a form of three dimensionality we call weak appears through differential rotation in individual 2D vortices. Second, strong three dimensionality characterized by vortex disruption leads on the one hand to a remarkable vortex array that is both steady and 3D, and, on the other hand, to scale-selective breakdown of two dimensionality in chaotic flows. Most importantly, these phenomena are entirely driven by inertia, so they are relevant to other flows with a tendency to two dimensionality, such as rotating, or stratified flows in geophysics and astrophysics.
我们通过实验研究了三维结构如何出现在壁面限制的磁流体动力学流动中。我们对立方容器中四边形涡旋阵列的破坏的分析突出了两种机制：首先，我们称之为弱的三维性通过单个二维涡旋的差速旋转出现。其次，由涡旋破坏引起的强三维性导致一方面出现一种稳定的、三维的显著涡旋阵列，另一方面，在混沌流中出现二维性的选择性破坏。最重要的是，这些现象完全是由惯性驱动的，因此它们与其他具有二维倾向的流动有关，如地球物理学和天体物理学中的旋转或分层流动。
