Pattern formation in non-equilibrium fluid, solid and multiphase systems

非平衡流体、固体和多相系统中的模式形成

• 批准号: RGPIN-2014-04359
• 负责人: Morris, Stephen
• 金额: $ 3.79万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=610985
• 关键词: Pattern; formation; non; equilibrium; fluid

Why does syrup coil when it hits a pancake? What determines the rippled shape of icicles? Why does lava sometimes crack into perfectly hexagonal columns? All these questions are the subject matter of Pattern Formation, the branch of Physics that deals with the emergence of ordered stuctures under driven, open, far-from-equilibrium conditions. Physics usually treats systems in a state of equilibrium, where they show no change in time. A perfect crystal is an example of order that appears in equilibrium. Ordered structures can also appear when a system is driven into motion by outside forces. In fact, most of the order we see in the universe is of this kind. This category of order encompasses everything from ripples on wind-blown sand to the structure of galaxies to Life Itself. Patterns have underlying symmetries and mathematical similarities that can be investigated by a combination of laboratory experiments, theory and computer simulation. Patterns exhibit universal behaviour across many length and time scales. The research program of the Experimental Nonlinear Physics Group at the University of Toronto involves work on icicle and stalactite shapes, patterns in the flow of viscous fluids, like honey, fracture patterns in cracking lava, the flow of liquid crystals and many other experiments. Our aim is to understand the Physics behind these diverse phenomena under the rubric of Pattern Formation, as well as to bring new physical understanding to patterns encountered in fields like geomorphology that are normally thought to be far removed from Physics.

为什么糖浆碰到煎饼会卷曲？是什么决定了冰柱的波纹形状？为什么熔岩有时会裂成完美的六边形柱？所有这些问题都是模式形成的主题，这是物理学的分支，研究在驱动、开放、远离平衡的条件下有序结构的出现。物理学通常处理处于平衡状态的系统，在这种状态下，它们不会随时间发生变化。完美的晶体是平衡状态下有序的一个例子。当系统被外力驱动而运动时，有序结构也会出现。事实上，我们在宇宙中看到的大部分秩序都是这样的。这类秩序包含了一切，从风吹沙上的涟漪到星系的结构，再到生命本身。模式具有潜在的对称性和数学相似性，可以通过实验室实验，理论和计算机模拟相结合来研究。模式在许多长度和时间尺度上表现出普遍的行为。多伦多大学实验非线性物理组的研究项目涉及冰柱和钟乳石形状、蜂蜜等粘性流体流动模式、熔岩破裂模式、液晶流动和许多其他实验。我们的目标是在模式形成的标题下理解这些不同现象背后的物理学，并为地貌学等领域中遇到的模式带来新的物理理解，这些领域通常被认为与物理学相去甚远。