论文标题
热和动量通量在对流表面层湍流中的持续性行为
Persistence behaviour of heat and momentum fluxes in convective surface layer turbulence
论文作者
论文摘要
壁挂式湍流中热和动量通量的表征对于众多应用至关重要，从工程到地球科学范围。但是，与速度和温度波动相关的湍流结构如何相互作用以产生新出现的通量特征，这是迄今为止尚不明显的。在这项工作中，我们通过研究从一个状态到另一个状态的湍流波动的间歇性波动的转换模式来研究这个基本问题，这一现象称为持久性。我们发现，热量和动量通量的持久性模式大不相同。此外，我们发现了导致这种行为的湍流运动的幂律缩放和长度尺度。此外，通过将通量事件的相和幅度分开，我们解释了对流湍流中热量和动量传递效率之间的起源和差异。我们的发现提供了对流动组织与通量产生机制之间的联系的新理解，这是湍流研究的两个基石。
The characterization of heat and momentum fluxes in wall-bounded turbulence is of paramount importance for a plethora of applications, ranging from engineering to Earth sciences. However, how the turbulent structures associated with velocity and temperature fluctuations interact to produce the emergent flux signatures, is not evident till date. In this work, we investigate this fundamental issue by studying the switching patterns of intermittently occurring turbulent fluctuations from one state to another, a phenomenon called persistence. We discover that the persistence patterns for heat and momentum fluxes are widely different. Moreover, we uncover power-law scaling and length scales of turbulent motions that cause this behavior. Furthermore, by separating the phases and amplitudes of flux events, we explain the origin and differences between heat and momentum transfer efficiencies in convective turbulence. Our findings provide new understanding on the connection between flow organization and flux generation mechanisms, two cornerstones of turbulence research.
