Model for propagation speed in turbulent channel flows.
Model for propagation speed in turbulent channel flows.
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DOI：
10.1103/physreve.86.046307
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发表时间：
2012-10
期刊：
影响因子：
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通讯作者：
J. Pei;J. Chen;Z. She;F. Hussain
中科院分区：
文献类型：
--
作者：
J. Pei;J. Chen;Z. She;F. Hussain
采用直接数值模拟（DNS）方法，计算了四种马赫数（M=0，0.8，2.0和3.0）下槽道湍流中流向速度脉动u'的传播速度Vc。在不同的M值下，Vc的分布具有明显的相似性.定量模型是根据一种称为速度-涡度相关结构（Vestivity Correlation Structure，Vestivity Correlation Structure）的统计结构开发的，Vestivity Correlation Structure定义为与固定位置的速度波动最相关的涡度区域。良好的协议与DNS测量的传播速度得到整个通道和所有M。结果证实了早先的推测，近壁传播是由于平流的相干涡结构，并验证了的概念，近壁传播。
The propagation speed Vc of the streamwise velocity fluctuations u' in turbulent channel flows is calculated using direct numerical simulation (DNS) data at four Mach numbers (M=0, 0.8, 2.0, and 3.0). The profiles of Vc are shown to display remarkable similarity at different M. Quantitative models are developed based on a statistical structure called Velocity-Vorticity Correlation Structure (VVCS), defined as the vorticity region most correlated to velocity fluctuations at a fixed location. Good agreement with DNS-measured propagation velocities is obtained throughout the channel and for all M. The result confirms earlier speculation that the near-wall propagation is due to an advection by coherent vortex structures, and validates the concept of the VVCS.