Secondary circulation within a mixing box and its effect on turbulence
Secondary circulation within a mixing box and its effect on turbulence
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混合箱内的二次循环及其对湍流的影响
DOI：
10.1007/s00348-020-03064-9
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发表时间：
2020
影响因子：
2.4
通讯作者：
Bennett, Sean
中科院分区：
文献类型：
--
作者：
Matinpour, Hadis;Atkinson, Joseph;Bennett, Sean
本文通过实验研究了格栅混合箱中二次环流的形成及其对湍流度的影响。该装置已被广泛用于研究各种地球物理背景下的湍流和混合，通常假设湍流几乎是各向同性和水平均匀的，并且它是零平均剪切流。然而，与这些假设不同的是，已经有报告指出，观察到的二次流型由两个大致对称的大尺度环流组成，在盒的中心有向上的流动，沿沿着有向下的回流。这些二次流似乎与不同的网格振荡条件和盒和网格的几何形状，和标准已被提出来描述的条件时，可能会出现二次流。实验进行了三种不同的组合的网格振荡冲程和频率，同时保持一个接近恒定的网格雷诺数，以检查的形成和二次流的强度和它的影响的大小和分布的盒子内的湍流。利用粒子图像测速仪（PIV）获得了流场的速度特性。结果表明：（1）二次环流存在于所有网格振荡条件的组合中;（2）随着冲程长度的增加，二次环流的强度和这些运动对总动能的贡献增加;（3）二次环流的存在导致网格附近区域更大的总体混合和湍流输送。这些见解预计将与广泛的混合箱应用相关。图形摘要
AbstractAn experimental study was conducted to examine the formation of secondary circulation in a grid-mixing box and to determine its effect on turbulence. This apparatus has been used extensively to study turbulence and mixing in a variety of geophysical contexts, and it is commonly assumed that turbulence is nearly isotropic and horizontally homogenous and that it is a zero-mean shear flow. Exceptions to these assumptions, however, have been reported, where a secondary flow pattern has been observed consisting of two roughly symmetric large-scale circulations with upward flow in the center of the box and downward return flow along the sides. These secondary flows appear to be associated with different grid oscillation conditions and box and grid geometries, and criteria have been proposed to describe conditions when secondary flow may be expected. Experiments were conducted for three different combinations of the grid oscillation stroke and frequency, while maintaining a near constant grid Reynolds number, to examine the formation and strength of the secondary flow and its effect on the magnitude and distribution of turbulence within the box. Velocity characteristics were obtained by particle image velocimetry (PIV). Results show that (1) secondary circulations were present for all combinations of the grid oscillation conditions; (2) as stroke length increased, the intensity of the secondary circulation and the contribution of these motions to total kinetic energy increased; and (3) the presence of secondary circulation results in greater overall mixing and turbulent transport in the region close to the grid. These insights are expected to be relevant to a wide range of mixing box applications.Graphic abstract
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影响因子：
1.5
作者：
Nobuhiro Matsunaga;Y. Sugihara;Toshimitsu Komatsu;Akira Masuda
通讯作者：
Akira Masuda
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影响因子：
2.4
作者：
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通讯作者：
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影响因子：
11.4
作者：
S. Bennett;J. Atkinson;Yinting Hou;M. Fay
通讯作者：
M. Fay
影响因子：
2.7
作者：
H. Matinpour;S. Bennett;J. Atkinson;M. Guala
通讯作者：
H. Matinpour;S. Bennett;J. Atkinson;M. Guala
水下水生植被对振荡网格引起的湍流影响的模型
DOI：
--
发表时间：
2012
期刊：
影响因子：
--
作者：
D. Pujol;J. Colomer;T. Serra;X. Casamitjana
通讯作者：
X. Casamitjana