Fully Coupled Two-Fluid Dynamics in Superfluid He4 : Anomalous Anisotropic Velocity Fluctuations in Counterflow
Fully Coupled Two-Fluid Dynamics in Superfluid He4 : Anomalous Anisotropic Velocity Fluctuations in Counterflow
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超流体 He4 中的完全耦合二流体动力学：逆流中的反常各向异性速度脉动
DOI：
10.1103/physrevlett.124.155301
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发表时间：
2020
影响因子：
8.6
通讯作者：
Guo, Wei
中科院分区：
文献类型：
--
作者：
Yui, Satoshi;Kobayashi, Hiromichi;Tsubota, Makoto;Guo, Wei
通过数值模拟两种流体，即量子化涡旋和正常流体的三维完全耦合动力学，研究了超流的热逆流。我们分析了层流正常流体的速度波动所产生的相互摩擦与超流分量的量子湍流。流向波动表现出更高的强度和更长范围的自相关，相比横向的。异常波动与可视化实验一致[Mastracciet al.，Phys. Rev. Fluids 4，083305（2019）PLFHBR 2469 -990X10.1103/PhysRevFluids.4.083305]，我们的结果证实了他们对各向异性波动的简单模型的分析。这一成功验证了完全耦合动力学模型的正确性，并为解决该双流体系统中的一些突出问题铺平了道路。
We investigate the thermal counterflow of the superfluidby numerically simulating three-dimensional fully coupled dynamics of the two fluids, namely quantized vortices and a normal fluid. We analyze the velocity fluctuations of the laminar normal fluid arising from the mutual friction with the quantum turbulence of the superfluid component. The streamwise fluctuations exhibit higher intensity and longer-range autocorrelation, as compared to transverse ones. The anomalous fluctuations are consistent with visualization experiments [Mastracciet al., Phys. Rev. Fluids 4, 083305 (2019)PLFHBR2469-990X10.1103/PhysRevFluids.4.083305], and our results confirm their analysis with simple models on the anisotropic fluctuations. This success validates the model of the fully coupled dynamics and paves the way for solving some outstanding problems in this two-fluid system.