Interaction of small scale Homogenenous Isotropic Turbulence with an Actuator Disk
Interaction of small scale Homogenenous Isotropic Turbulence with an Actuator Disk
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小尺度均匀各向同性湍流与致动器盘的相互作用
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
A. Towne
中科院分区：
文献类型：
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作者：
A. Ghate;N. Ghaisas;S. Lele;A. Towne
采用高分辨率大涡模拟研究了拖曳固定推力系数驱动盘与不同空间积分长度尺度和耗散率的衰减均匀各向同性湍流（HIT）的相互作用。详细描述了湍流压力的调制、流入湍流进入核心时的变形以及尾流剪切层湍流，并报道了与该问题建模相关的各种湍流量。剪切层卷带（因此尾迹恢复）对上游HIT的积分长度尺度（与其强度相反）非常敏感，并且使用流场的时空模态分解来确定主导剪切层增长速率的开尔文-亥姆霍兹波包，从而协调了这一观察结果。
The interaction of a dragging, fixed thrust coefficient actuator disk with decaying homogeneous isotropic turbulence (HIT) of varying spatial integral length scales and dissipation rates is studied using Large Eddy Simulation performed at high resolution. Modulation of the turbulence pressure, the deformation of the inflow turbulence as it enters the core, and the wake shear layer turbulence are characterized in detail, and various turbulence quantities pertinent for modeling the problem are reported. The shear layer entrainment (and hence wake recovery) is shown to be strongly sensitive to the integral length scale of the upstream HIT (as opposed to its intensity), and this observation is reconciled using a space-time modal decomposition of the flow field to identify the dominant Kelvin-Helmholtz wavepackets that dictate the shear layer growth rate.