在衰变流中普遍速度统计
Christian Küchler1, Gregory P Bewley2, Eberhard Bodenschatz3
1Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany; Institute for Dynamics of Complex Systems, University of Göttingen, Göttingen, Germany; and Max Planck University of Twente Center for Complex Fluid Dynamics, Göttingen, Germany and Twente, Netherlands.
Physical review letters
|July 28, 2023
概括
流在不同尺度上转移能量. 实验表明速度差异是雷诺兹数独立的,但偏离了经典的功率定律,建议进行对数校正.
科学领域:
- 流体动力学 流体动力学
- 流的研究研究.
- 统计力学就是统计力学.
背景情况:
- 流表现出从大到小的能量转移,最终以热的形式消散.
- 科尔莫戈罗夫的1941年推测假定惯性力在高雷诺兹数的惯性范围内主导能量转移.
- 对于惯性范围内的速度差统计数据的普遍功率定律是理论上预测的.
研究的目的:
- 在流中实验研究速度差统计的行为.
- 为了测试科尔摩戈罗夫的猜想和功率定律的普遍性,在广泛的雷诺兹数范围内.
- 在高雷诺兹数流中识别经典功率定律预测的偏差.
主要方法:
- 在马克斯·普朗克变频密度流道 (Max Planck Variable Density Turbulence Tunnel) 中,在一个精心控制的风洞流中进行的实验.
- 测量二次速度差统计数据在雷诺兹数的前所未有的范围.
- 分析流数据以确定缩放定律和雷诺兹数依赖关系.
主要成果:
- 测量了二次速度差统计数据,证明它与雷诺兹数独立.
- 观察到普遍的行为,与衰变的流相一致.
- 经典的功率定律甚至在测试的最高雷诺兹数时也没有被观察到.
结论:
- 这些发现表明,雷诺兹数独立的对经典功率定律进行了对衰变流的逻辑校正.
- 这些结果挑战了现有的理论预测,并要求进一步发展理论.
- 突出了在流中普遍行为的实验验证,与简单功率规律的偏差,是突出.
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