Repeller or Attractor? Selecting the Dynamical Model for the Onset of Turbulence in Pipe Flow
Repeller or Attractor? Selecting the Dynamical Model for the Onset of Turbulence in Pipe Flow
复制标题
DOI：
10.1103/physrevlett.101.214501
复制
发表时间：
2008-11-21
影响因子：
8.6
通讯作者：
Westerweel, Jerry
中科院分区：
文献类型：
--
作者：
Hof, Bjoern;de Lozar, Alberto;Westerweel, Jerry
在低雷诺数的剪切流中可以观察到湍流的崩溃，这提出了一个问题：湍流通常具有瞬态性质还是在某个临界点变得持续。最近的数据导致与大多数支持湍流转变为吸引状态模型的研究存在相互矛盾的观点。在这里，我们提出了管流湍流的寿命测量，时间跨度达 8 个数量级，极大地扩展了之前的所有研究。我们表明，该政权不存在临界点，并且与普遍观点相反，动荡状态仍然是短暂的。据我们所知，这是对湍流中超指数瞬变的首次观察，证实了源自低维系统的猜想。
The collapse of turbulence, observable in shear flows at low Reynolds numbers, raises the question if turbulence is generically of a transient nature or becomes sustained at some critical point. Recent data have led to conflicting views with the majority of studies supporting the model of turbulence turning into an attracting state. Here we present lifetime measurements of turbulence in pipe flow spanning 8 orders of magnitude in time, drastically extending all previous investigations. We show that no critical point exists in this regime and that in contrast to the prevailing view the turbulent state remains transient. To our knowledge this is the first observation of superexponential transients in turbulence, confirming a conjecture derived from low-dimensional systems.