罕见的,噪声引起的,绕过过渡在平面库埃特流可以绕过瞬时
1Laboratoire de Mécanique des Fluides de Lille (LMFL), Kampé de Fériet, Univ. Lille, CNRS, ONERA, Arts et Métiers Institute of Technology (ENSAM), école centrale de Lille, UMR 9014, F-59000 Lille, France.
Physical review. E
|February 7, 2025
概括
这项研究研究了平面Couette流中从层状流向流的罕见过渡. 研究人员发现,这些转变涉及大规模的能量再分配,在旋转出现之前形成速度管,这是一个两阶段的过程,与典型的瞬间路径不同.
科学领域:
- 流体动力学 流体动力学
- 流理论是关于流的.
- 非线性动力学是一种非线性动力学.
背景情况:
- 平面库埃特流是流体动力学的一个基本模型.
- 了解从层状流向流的过渡对于许多应用至关重要.
- 噪声诱导的过渡是非线性系统中的一个关键现象.
研究的目的:
- 为了研究罕见的噪声诱导的过渡从层状流向流在平面库埃特流.
- 为了确定这些过渡路径是否与更简单的系统中的噪声诱导过渡具有相同的特性.
- 在过渡期间分析能量再分配和结构形成的动态.
主要方法:
- 适应性多层分离用于罕见事件模拟.
- 直接进行数值模拟以进行验证.
- 分析流动轨迹和能量谱的分析.
- 对域名大小效应的研究.
主要成果:
- 罕见的过渡路径涉及从小到大规模的非线性能量再分配.
- 流向速度管首先形成,其次是流向旋,表明两阶段的过渡.
- 随着域大小的增加,观察到空间定位和连贯结构的扩展.
- 计算的路径表现出一些实时特征,但缺乏关键特征,如位点邻里访问.
结论:
- 观察到的两阶段过渡过程与墙壁流中的经典实时行为有所不同.
- 这些差异表明,在将传统的瞬间计算应用到围墙流时,存在挑战.
- 可能需要进一步的研究来理解在非常低的能量速率下即时重新连接.
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