Spatio-Temporal Chaos in Systems of Broken Symmetry

对称破缺系统中的时空混沌

• 批准号: 0305151
• 负责人: Eberhard Bodenschatz
• 金额: --
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0305151&HistoricalAwards=false
• 关键词: Spatio; Temporal; Chaos; Systems; Broken

This experimental project will continue investigations of non-linear, non-equilibrium pattern-forming phenomena in extended dynamical systems. The system of interest is thermal convection found in pressurized gases confined between two parallel plates. This system, and many others, exhibits non-transient states in which spatial and temporal correlations fall off quickly. These complex states are termed "Spatio-Temporal Chaos"(STC), and have received much attention in recent years. An open question addressed in this project, is how to interact with or even control STC. The research will address how thermal convection responds to spatial and spatio-temporal forcing. Two types of forcing schemes will be applied. The first uses micro-machined surfaces that are manufactured at Cornell's Nano Fabrication Facility, the second a thermal imprinting technique. Better knowledge of STC may potentially impact fundamental science areas such as physics, biology, and medicine, but also applied areas, like heating technology, materials processing, etc. The experimental results will also provide a benchmark for numerical codes developed for solving hydrodynamical problems on supercomputers. The investigation includes an international collaboration with Prof. W. Pesch (Germany) and Steve Lipson (Israel). In addition, a collaboration with Richard Wiener from Pacific University will be continued. Graduate students involved in the project and in this research group receive training in cutting edge experimental techniques ranging from microfabrication, design of mechanical and electronic systems, to digital image processing. This experience provides graduate students with training and preparation for careers in academe, industry, and government.This experimental research program continues an investigation into the pattern formation that occurs in thermally driven flows in pressurized gases confined between two parallel plates. The patterns are visible optically as spontaneous density fluctuations in the gas. The project will examine situations where the flow shows highly disordered convection patterns. Such situations also occur in everyday life; an example is striped cloud-streaks in the sky or in the somewhat repetitive patterns of windblown sand. The dynamics of these complex patterns is significant current scientific interest. An important question that will be addressed in this research program is how to interact with or even control these states that are chaotic both in space and time. This research program will address this question by using micro-machined surfaces that are manufactured at Cornell's Nano Fabrication Facility and by using thermal imprinting techniques. A better knowledge of these spatio-temporal chaotic states and their control can have an impact in both fundamental science, like physics, biology, and medicine (as in cardiac fibrillation, epilepsy), as well as in technology, like heating technology, materials processing, etc. The investigation includes an international collaboration with Prof. W. Pesch (Germany) and Steve Lipson (Israel). In addition, a collaboration with Richard Wiener from Pacific University will be continued. Graduate students involved in the project and in this research group receive training in cutting edge experimental techniques ranging from microfabrication, design of mechanical and electronic systems, to digital image processing. This experience provides graduate students with training and preparation for careers in academe, industry, and government.

这个实验项目将继续研究扩展动力系统中的非线性、非平衡模式形成现象。感兴趣的系统是在两个平行板之间的加压气体中发现的热对流。这个系统和许多其他系统一样，表现出非瞬态，在这种状态下，空间和时间相关性会迅速下降。这些复杂的状态被称为“时空混沌”（spatial - temporal Chaos， STC），近年来受到了广泛关注。在这个项目中解决的一个开放问题是如何与STC交互甚至控制STC。该研究将探讨热对流如何响应空间和时空强迫。将采用两种强制方案。第一个使用由康奈尔纳米制造工厂制造的微机械表面，第二个使用热压印技术。更好地了解STC可能会影响基础科学领域，如物理、生物和医学，以及应用领域，如加热技术、材料加工等。实验结果也将为在超级计算机上求解流体动力学问题开发数值代码提供基准。该研究包括与W. Pesch教授（德国）和Steve Lipson（以色列）的国际合作。此外，将继续与太平洋大学的Richard Wiener合作。参与该项目的研究生和本研究小组接受尖端实验技术的培训，范围从微加工、机械和电子系统设计到数字图像处理。这种经历为研究生在学术界、工业界和政府的职业生涯提供了培训和准备。这个实验研究项目继续调查在两个平行板之间的加压气体的热驱动流动中发生的模式形成。这些图案在光学上是可见的，因为气体中的自发密度波动。该项目将检查气流显示高度无序对流模式的情况。这种情况在日常生活中也会发生；例如，天空中的条纹云或被风吹过的沙子的重复图案。这些复杂模式的动态是当前科学的重要兴趣。在这个研究项目中要解决的一个重要问题是如何与这些在空间和时间上都是混沌的状态相互作用甚至控制它们。这个研究项目将通过使用康奈尔纳米制造工厂制造的微机械表面和热印迹技术来解决这个问题。更好地了解这些时空混沌状态及其控制可以对基础科学（如物理学、生物学和医学（如心脏颤动、癫痫））以及技术（如加热技术、材料加工等）产生影响。该研究包括与W. Pesch教授（德国）和Steve Lipson（以色列）的国际合作。此外，将继续与太平洋大学的Richard Wiener合作。参与该项目的研究生和本研究小组接受尖端实验技术的培训，范围从微加工、机械和电子系统设计到数字图像处理。这种经历为研究生在学术界、工业界和政府的职业生涯提供了培训和准备。