论文标题
基于光谱尺度的扩展到附着的壁扰动模型
A spectral-scaling based extension to the attached eddy model of wall-turbulence
论文作者
论文摘要
在摩擦雷诺数（2400至26000）下测量的流速速度分量的二维（2-D）光谱，用于完善湍流边界层对数区域的模型。在这里，我们关注所附涡模型（AEM）。传统的AEM假设边界层仅由自相似壁连接的层次结构（$ type \，$ $）eddies。尽管$ type \ a $ eddies代表了高雷诺数在高雷诺数下的主要能量大规模动作，但观察到没有用这种涡流代表的尺度含有很大比例的总动能。因此，在本研究中，我们提出了一个扩展的AEM，其中包含了另外两个代表性的涡流。这些涡流称为$ type \，c_a $和$ type \，ss $，分别代表自相似但壁成分的低雷诺数特征，分别代表了非sefl-self Similar Suminer壁挂式上层建筑。显示扩展的AEM可以更好地预测更大的能量长度尺度，并捕获所有三个速度组件的2-D光谱中的低和高元素缩放趋势。还提出了有关光谱自相似性和相关$ k^{ - 1} $缩放定律的讨论。
Two-dimensional (2-D) spectra of the streamwise velocity component, measured at friction Reynolds numbers ranging from 2400 to 26000, are used to refine a model for the logarithmic region of turbulent boundary layers. Here, we focus on the attached eddy model (AEM). The conventional AEM assumes the boundary layer to be populated with hierarchies of self-similar wall-attached ($Type\,A$) eddies alone. While $Type\,A$ eddies represent the dominant energetic large-scale motions at high Reynolds numbers, the scales that are not represented by such eddies are observed to carry a significant proportion of the total kinetic energy. Therefore, in the present study, we propose an extended AEM that incorporates two additional representative eddies. These eddies, named $Type\,C_A$ and $Type\,SS$, represent the self-similar but wall-incoherent low-Reynolds number features, and the non-self-similar wall-coherent superstructures, respectively. The extended AEM is shown to better predict a greater range of energetic length scales and capture the low- and high-Reynolds number scaling trends in the 2-D spectra of all three velocity components. A discussion on spectral self-similarity and the associated $k^{-1}$ scaling law is also presented.
