Persistent Non-Homogeneous Features in Periodic Channel-Flow Simulations
Persistent Non-Homogeneous Features in Periodic Channel-Flow Simulations
复制标题
周期性通道流模拟中的持续非均匀特征
DOI：
10.1007/s10494-009-9209-z
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Fishpool G
中科院分区：
文献类型：
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作者：
Fishpool G
简单剪切流（如边界层和槽道流）的时间分辨模拟通常用于前体模拟，为模拟更复杂几何形状内和周围的湍流提供流入边界条件。对于前兆和主要模拟，计算的平均流量的准确性依赖于模拟运行足够长的时间以包含湍流过程的全部频谱，从而产生物理上有效的统计表示。从简单剪切流的基本研究中获得统计收敛所需的时间尺度是基于在流动几何形状不变的空间方向上平均的数据，即均匀性被认为是极限情况的方向。本文报告和讨论的功能，代表显着偏离空间均匀性的流动在这样一个方向上，坚持在这个时间尺度上，从而限制了模拟湍流流入的空间均匀性。特征的持久性和大小被量化。一系列的模拟域尺寸和流动参数的不同组合已经进行了两个独立的代码（DNS和LES），以探索如何控制的持久性和大小。虽然没有明确的物理机制已被确定，有人建议，功能可能与实验观察壁有界流动中的持久性结构。
Time-resolved simulations of simple shear flows, such as boundary layers and channel flows, are often used asprecursor simulationsthat provide the inflow-boundary conditions for simulations of turbulent flows in and around more complex geometries. For both the precursor and main simulations, the accuracy of the calculated mean flow relies on the simulations being run for long enough to contain the full spectrum of turbulent processes, resulting in a physically valid statistical representation. The time scale needed to achieve convergence of statistics from fundamental studies of simple shear flows is based on data that is averaged in spatial directions in which the flow geometry is invariant—i.e. directions in which homogeneity is expected to be the limiting case. This paper reports and discusses features that represent significant departures from spatial homogeneity of the flow in such a direction, that persist on this time scale, thereby limiting the spatial uniformity of a simulated turbulent inflow. The persistence and size of the features is quantified. A range of simulations for different combinations of domain dimensions and flow parameters has been performed with two independent codes (DNS and LES) to explore how the persistence and size are controlled. While no definitive physical mechanism has been identified, it is suggested that the features may be related to experimental observations of persistent structures in wall-bounded flows.
高雷诺数下纳维-斯托克斯方程的显式分步格式的稳定性界限
DOI：
--
发表时间：
2009
期刊：
影响因子：
--
作者：
G. Fishpool;M. Leschziner
通讯作者：
M. Leschziner
湍流河道流中的平面波和结构
DOI：
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发表时间：
1990
期刊：
影响因子：
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作者：
L. Sirovich;K. Ball;L. Keefe
通讯作者：
L. Keefe