Viscous tilting and production of vorticity in homogeneous turbulence
Viscous tilting and production of vorticity in homogeneous turbulence
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均匀湍流中的粘性倾斜和涡度的产生
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
A. Tsinober
中科院分区：
文献类型：
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作者：
M. Holzner;M. Guala;B. Luthi;Alexander Liberzon;N. Nikitin;W. Kinzelbach;A. Tsinober
粘性涡量消耗是湍流的一个基本和众所周知的性质，它平衡了与涡拉伸机制相关的净涡量产生。然而，在这封信中，我们证明了粘性效应并不局限于一个单纯的破坏过程，而是在涡度动力学中发挥着与涡拉伸一样重要的更复杂的作用。基于三维粒子跟踪测速实验和对均匀湍流和准各向同性湍流的直接数值模拟结果，我们表明涡量方程中的粘性项也可以局部诱导涡量的产生和涡量矢量方向的改变（粘性倾斜）。
Viscous depletion of vorticity is an essential and well known property of turbulent flows, balancing, in the mean, the net vorticity production associated with the vortex stretching mechanism. In this letter, we, however, demonstrate that viscous effects are not restricted to a mere destruction process, but play a more complex role in vorticity dynamics that is as important as vortex stretching. Based on the results from three dimensional particle tracking velocimetry experiments and direct numerical simulation of homogeneous and quasi-isotropic turbulence, we show that the viscous term in the vorticity equation can also locally induce production of vorticity and changes of the orientation of the vorticity vector (viscous tilting).