Interacting Vortices, their Formation and Evolution

非技术：漩涡在流体中无处不在，可以在小到一毫米的几分之一到大到数百公里的尺度上形成。飓风的形成只是大尺度大气现象的一个极端例子，它可以造成毁灭性的后果。这一提议旨在理解控制二维流体薄片中漩涡形成、相互作用和演化的基本物理学。据信，如果流体流动主要是二维和湍流的，如在大气和海洋中，流动可以自组织成大型的动力结构。一种数学理论，类似于化学物质混合的热力学理论，被用来解释这一非凡的过程。这个提议是试图用控制良好的实验室实验来检验这样一个理论。这项研究的一个重要部分是教育和训练不同层次的学生，他们将成为科学和工程的新成员。这个研究项目本身对学生很有吸引力，因为物理现象很有趣，视觉上很愉悦。技术：本提案旨在理解控制二维流体薄片中漩涡形成、相互作用和演变的基本物理。后一种特性可以防止涡旋拉伸，并被认为是形成具有显著稳定性的大尺度相干结构的原因。与自然界中发生的漩涡不同，实验室漩涡可以以可控的方式产生，从而可以进行详细的研究。假设这些大尺度相干结构的稳定性是由于系统接近于由最大混合熵原理控制的唯一状态。这是一个重要的假设，我们的实验旨在测试熵原理是否适用于涡旋以及普通的热力学系统。这项研究的一个重要部分是教育和训练科学和工程领域的新学生。这个研究项目本身对所有年龄段的学生都很有吸引力，因为物理现象很有趣，但在视觉上令人愉悦。

Non-Technical:Vortices are ubiquitous in fluids and can form on scales as small as a fraction of a millimeter to as large as hundreds of kilometers. The formation of hurricanes is just one of the extreme examples of large- scale atmospheric phenomenon, which can have devastating consequences. This proposal is aimed at understanding fundamental physics that governs the formation, interaction, and evolution of vortices in a thin sheet of fluid that behave two dimensionally. It is believed that if fluid flow is predominantly two dimensional and turbulent, as in the atmosphere and in oceans, the flow can self organize into large, power structures. A mathematical theory, similar to thermodynamic theory of mixing of chemicals, has been formulated to explain this remarkable process. This proposal is an attempt to test such a theory using well-controlled laboratory experiments. A significant part of this research is to educate and train students, at different levels, who will be the new to science and engineering. The research project itself is very attractive to students because the physical phenomena are intriguing and visually pleasing.Technical:This proposal is aimed at understanding fundamental physics that governs the formation, interaction, and evolution of vortices in thin sheets of fluid that behave two dimensionally. This latter property prevents vortex stretching and is believed to be responsible for the formation of large-scale coherent structures with remarkable stability. Unlike vortices occurring in nature, laboratory vortices can be created in a controlled manner, allowing detailed studies to be carried out. It has been postulated that stability of these large-scale coherent structures results from the system being close to a unique state governed by the principle of maximum mixing entropy. This is an important hypothesis and our experiment is designed to test whether this entropy principle works for vortices as well as for an ordinary thermodynamic system. A significant part of this research is to educate and train students who will be new to science and engineering. The research project itself is very attractive to students of all age groups because the physical phenomena are intriguing but visually pleasing.