管道流中从精确相干解涌现的时空动力学
流体动力学
2016-08-16 v2
摘要
湍流-层流图样在壁面有界剪切流中转捩附近无处不在。尽管近期在类比非平衡相变描述其动力学方面取得了进展，仍无理论解释其涌现。动力学系统方法表明，Navier--Stokes equations 的不变解，如管道流中的行波与相对周期轨道，充当了无序动力学的构建块。虽然近期研究已展示瞬态混沌如何从这些解中产生，但随之而来的动力学缺乏实验中观测到的湍流斑在尺寸、形状和速度上的强烈涨落。我们在此展示，具有不同动力学和运动学性质的混沌斑在相空间中合并，并产生了管道流中观测到的增强时空图样。这为壁面有界扩展剪切流中湍流-层流图样的现象学提供了动力学系统基础。
引用
@article{arxiv.1512.02382,
title = {Emergence of spatio-temporal dynamics from exact coherent solutions in pipe flow},
author = {Paul Ritter and Fernando Mellibovsky and Marc Avila},
journal= {arXiv preprint arXiv:1512.02382},
year = {2016}
}
备注
Implemented changes after peer review. Besides some minor tweaking the major ones were: The new title better reflects the scope of the paper. We have rewritten Section V to make a more compelling case. The caption of Figure 6 more clearly describes the global dynamics close to the boundary crisis. In the conclusion we now discuss the challenge of addressing the problem in full space