Direct measurement of the energy dissipated by quantum turbulence
Direct measurement of the energy dissipated by quantum turbulence
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DOI：
10.1038/nphys1963
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发表时间：
2011-06-01
期刊：
影响因子：
19.6
通讯作者：
Tsepelin, V.
中科院分区：
文献类型：
--
作者：
Bradley, D. I.;Fisher, S. N.;Tsepelin, V.
由于没有一个通用的解决方案，以控制Navier-Stokes方程意味着没有基本的理论湍流。在简单的纯量子湍流的情况下，在T类似于O的超流体中，相同的单量子化涡旋的纠缠可能会提供对湍流的更深入的理解。著名的Kolmogorov理论（1）预测了湍流的能量分布及其如何衰减。在正常的系统中，湍流能量通常只是对支撑介质的总热能的小扰动。然而，在量子湍流中，能量是可以获得的。一个静止的凝聚物必然处于零焓的基态。因此，量子湍流占了超流体的全部自由能，没有其他贡献。在这里，我们利用这一性质，使自由衰减的量子湍流释放的能量的第一个直接测量。我们的结果是一致的Kolmogorov能谱与推断Kolmogorov常数非常相似的经典流体。
The lack of a general solution to the governing Navier-Stokes equations means that there is no fundamental theory of turbulence. In the simpler case of pure quantum turbulence, the tangle of identical singly quantized vortices in superfluids at T similar to O may provide a deeper understanding of turbulence in general. The well-known Kolmogorov theory(1) predicts the energy distribution of turbulence and how it decays. In normal systems the turbulent energy is generally only a small perturbation on the total thermal energy of the supporting medium. In quantum turbulence, however, the energy is accessible. A stationary condensate is necessarily in its ground state with zero enthalpy. Thus quantum turbulence accounts for the entire free energy of the superfluid and there are no other contributions. Here, we exploit this property to make the first direct measurement of the energy released by freely decaying quantum turbulence. Our results are consistent with a Kolmogorov energy spectrum with an inferred Kolmogorov constant remarkably similar to those of classical fluids.