How linear is wall-bounded turbulence?
How linear is wall-bounded turbulence?
复制标题
壁面湍流的线性程度如何？
DOI：
10.1063/1.4819081
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发表时间：
2013
影响因子：
4.6
通讯作者：
J. Jiménez
中科院分区：
文献类型：
--
作者：
J. Jiménez
Orr的无粘机制的相关性的瞬态放大剪切流中的扰动进行了探讨的背景下爆发的对数层的壁边界湍流。壁法向速度的线性化问题首先解决了小粘度的限制，均匀剪切和一个通道的conventent-like的轮廓，并与准周期爆发的完全湍流模拟箱设计为最小的对数层。许多属性，如时间和长度尺度，组件之间的能量通量，和倾角，同意以及两个系统之间。然而，一旦平均流的平流被减去，湍流加速度的直接计算的线性分量被发现是一个小的一部分的总数。湍流爆发中不同数量的时间相关性意味着经典模型，其中壁面法向速度产生的破坏的流向速度条纹，是…
The relevance of Orr's inviscid mechanism to the transient amplification of disturbances in shear flows is explored in the context of bursting in the logarithmic layer of wall-bounded turbulence. The linearized problem for the wall normal velocity is first solved in the limit of small viscosity for a uniform shear and for a channel with turbulent-like profile, and compared with the quasiperiodic bursting of fully turbulent simulations in boxes designed to be minimal for the logarithmic layer. Many properties, such as time and length scales, energy fluxes between components, and inclination angles, agree well between the two systems. However, once advection by the mean flow is subtracted, the directly computed linear component of the turbulent acceleration is found to be a small part of the total. The temporal correlations of the different quantities in turbulent bursts imply that the classical model, in which the wall-normal velocities are generated by the breakdown of the streamwise-velocity streaks, is ...