RUI: The effects of three-dimensional fluid flows on front propagation

非技术摘要流体流动在许多物理、化学、地质、天体物理和生物过程中起着至关重要的作用。在过去的十年里，PI的研究小组对简单的二维(2D)流体流动中的反应前锋行为进行了大量的实验。这些实验的结果导致了一种理论的发展，该理论预测了流动中存在“燃烧不变流形”(BIM)，这些流形充当阻止反应前沿运动的无形屏障。由这笔资金资助的实验将把这些研究扩展到三维流动。特别是，我们将探索3D流动中的BIM是否仍然充当阻碍反应前锋运动的障碍。最终，这些实验可能有助于更好地了解浮游生物在海洋中的繁殖；更高效的化学反应，特别是在微型设备中；等离子流动中可能导致经济的聚变发电的过程；细胞尺度流动在生物过程中的作用，包括发育中的胚胎的形态形成；超新星爆炸；以及人口流动对疾病传播的影响。这是一项RUI(本科院校研究)资助；因此，所有这项研究都将与本科生一起完成，他们将在研究的各个方面发挥积极作用，包括实验设计、仪器的建造和测试、数据收集和分析以及结果的发布和展示。这将是大多数学生第一次真正的研究经历，并将在他们作为科学家的发展中发挥重要作用。技术摘要这笔拨款将用于资助研究三维(3D)流体流动中反应前锋行为的实验。这是一个在物理、化学、生物和地质学的广泛前沿生产系统中应用的问题。PI有丰富的经验，在2D流动中做类似的实验(都是本科生做的)。这些实验的结果导致了一种理论的发展，该理论确定了流动中的“燃烧不变流形”(BIM)，这些流形充当阻挡反应前沿的障碍。拟议的实验将把这些研究扩展到由嵌套涡链组成的三维流动。反应前锋将由可激发的别洛索夫-扎博廷斯基化学反应产生，该化学反应已被证明表现出与广泛的前锋产生系统的动力学相似的动力学。本研究涉及的问题包括：(A)BIM理论能否推广到全3D问题；(B)在3D流动中是否仍然存在类似于2D流动中的BIM的势垒；以及(C)3D流动中的反应势垒是否可以被弱的时间依赖性所破坏。这是一项RUI(本科院校研究)资助；因此，所有这项研究都将与本科生一起完成，他们将在研究的各个方面发挥积极作用，包括实验设计、仪器的建造和测试；数据收集和分析；以及结果的发布和展示。这些将是这些学生第一次真正的研究经历，并将在他们作为科学家的发展中发挥重要作用。

Non-Technical abstractFluid flows play a crucial role in the behavior of many physical, chemical, geological, astrophysical and biological processes. During the past ten years, the PI's research group has done numerous experiments on the behavior of reaction fronts in simple, two-dimensional (2D) fluid flows. Results from those experiments have led to development of a theory that predicts the existence of "burning invariant manifolds" (BIMs) in the flow that act as invisible barriers that block the motion of reaction fronts. The experiments funded by this grant will extend those studies to three-dimensional (3D) flows. In particular, we will explore whether BIMs in 3D flows still act as barriers that impede the motion of reaction fronts. Ultimately, these experiments may lead to a better understanding of blooms of plankton in the oceans; more efficient chemical reactors, especially in micro-scale devices; processes in plasma flows that might lead to economical fusion-based electrical generation; the role of cellular-scale flows in biological processes including morphogenesis in a developing embryo; detonation of supernova explosions; and the effects of moving populations on the spreading of a disease. This is an RUI (Research at Undergraduate Institutions) grant; consequently, all of this research will be done with undergraduate students who will play an active role in all aspects of the studies, including experimental design, building and testing of the apparatus, data collection and analysis, and publication and presentation of the results. These will be the first real research experiences for most of these students, and will play an important role in their development as scientists.Technical AbstractThis grant will fund experiments that will study the behavior of reaction fronts in three-dimensional (3D) fluid flows. This is an issue with applications to a wide range of front-producing systems in physics, chemistry, biology and geology. The PI has extensive experience doing similar experiments (all with undergraduates) in 2D flows. Results from those experiments led to the development of a theory that identifies "burning invariant manifolds" (BIMs) in the flow that act as barriers that block reaction fronts. The proposed experiments will extend those studies to 3D flows composed of nested chains of vortices. Reaction fronts will be produced by the excitable Belousov-Zhabotinsky chemical reaction which has been shown to exhibit dynamics similar to those for a wide range of front-producing systems. Questions addressed by this research will include: (a) whether the BIM theory can be extended to the full 3D problem; (b) whether barriers similar to the BIMs in the 2D flows still exist to front propagation in 3D flows; and (c) whether reaction barriers in 3D flows can be destroyed by weak time dependence. This is an RUI (Research at Undergraduate Institutions) grant; consequently, all of this research will be done with undergraduate students who will play an active role in all aspects of the studies, including experimental design, building and testing of the apparatus; data collection and analysis; and publication and presentation of the results. These will be the first real research experiences for most of these students, and will play an important role in their development as scientists.