Depolarization of decaying counterflow turbulence in He II.
Depolarization of decaying counterflow turbulence in He II.
复制标题
He II 中衰减逆流湍流的去极化。
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
L. Skrbek
中科院分区：
文献类型：
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作者：
C. Barenghi;A. Gordeev;L. Skrbek
本文给出了数值模拟支持的实验证据，证明传热逆流在He II中产生的稳态涡缠结是强极化的。当产生逆流乱流的加热器关闭时，漩涡缠结衰减，漩涡线的空间方向随机化，漩涡缠结的极化减小。去极化过程减缓了测量旋涡线密度的横向第二声信号的恢复；在某些参数值下，它甚至导致横向第二声振幅的净减小，而不是达到有限尺寸通道中典型的均匀各向同性湍流的普遍-32次幂时间律衰减。
We present experimental evidence backed up by numerical simulations that the steady-state vortex tangle created in He II by heat-transfer counterflow is strongly polarized. When the heater that generates the counterflow turbulence is switched off, the vortex tangle decays, the vortex lines randomize their spatial orientation and the tangle's polarization decreases. The process of depolarization slows down the recovery of the transverse second sound signal which measures the vortex line density; at some values of parameters it even leads to a net decrease of the amplitude of the transverse second sound prior to reaching the universal -32 power temporal law decay typical of classical homogeneous isotropic turbulence in a finite-sized channel.