Teikyo University, 6-22 Misakimachi, Omuta-city, Fukuoka 836-8505, Japan.
Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga-Koen, Kasuga-city, Fukuoka 816-8580, Japan.
Sci Rep. 2016 Sep 15;6:33371. doi: 10.1038/srep33371.
Turbulence and its structure formation are universal in neutral fluids and in plasmas. Turbulence annihilates global structures but can organize flows and eddies. The mutual-interactions between flow and the eddy give basic insights into the understanding of non-equilibrium and nonlinear interaction by turbulence. In fusion plasma, clarifying structure formation by Drift-wave turbulence, driven by density gradients in magnetized plasma, is an important issue. Here, a new mutual-interaction among eddy, drift wave and flow in magnetized plasma is discovered. A two-dimensional solitary eddy, which is a perturbation with circumnavigating motion localized radially and azimuthally, is transiently organized in a drift wave - zonal flow (azimuthally symmetric band-like shear flows) system. The excitation of the eddy is synchronized with zonal perturbation. The organization of the eddy has substantial impact on the acceleration of zonal flow.
湍流及其结构形成在中性流体和等离子体中是普遍存在的。湍流会湮灭整体结构，但也可以组织流动和旋涡。流动和旋涡之间的相互作用为理解非平衡和非线性相互作用提供了基本的认识。在聚变等离子体中，由磁化等离子体中的密度梯度驱动的漂移波湍流导致的结构形成是一个重要的问题。在这里，发现了磁化等离子体中旋涡、漂移波和流动之间的一种新的相互作用。二维孤立旋涡是一种具有环绕运动的局部化的扰动，在漂移波-纬流（轴对称带状剪切流）系统中暂态地组织起来。旋涡的激发与纬向扰动同步。旋涡的组织对纬向流的加速有很大的影响。
