Visualization of the normal-fluid turbulence in counterflowing superfluid 4He
Visualization of the normal-fluid turbulence in counterflowing superfluid 4He
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DOI：
10.1103/physrevb.91.094503
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发表时间：
2015-03-06
影响因子：
3.7
通讯作者：
Vinen, W. F.
中科院分区：
文献类型：
--
作者：
Marakov, A.;Gao, J.;Vinen, W. F.
我们描述了一种技术，利用飞秒激光场电离氦原子产生的三线态He-2* 分子示踪剂的细线，用于可视化超流He-4中正常流体的流动，以及其在通道中热逆流的应用。我们表明，在相对较小的速度，超流体已经湍流，正常流体的流动仍然是层流，但与扭曲的速度分布，而在较高的速度有一个过渡到湍流。在这种湍流状态下的结构函数的形式显着不同于在传统的湍流类型中发现的。这种可视化技术也有望适用于其他涉及低温氦的流体动力学问题。
We describe a technique, using thin lines of triplet-state He-2* molecular tracers created by femtosecond-laser field ionization of helium atoms, for visualizing the flow of the normal fluid in superfluid He-4, together with its application to thermal counterflow in a channel. We show that, at relatively small velocities, where the superfluid is already turbulent, the flow of the normal fluid remains laminar, but with a distorted velocity profile, while at a higher velocity there is a transition to turbulence. The form of the structure function in this turbulent state differs significantly from that found in types of conventional turbulence. This visualization technique also promises to be applicable to other fluid dynamical problems involving cryogenic helium.