Dual cascade and dissipation mechanisms in helical quantum turbulence
Dual cascade and dissipation mechanisms in helical quantum turbulence
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DOI：
10.1103/physreva.95.053636
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发表时间：
2017-05-26
影响因子：
2.9
通讯作者：
Brachet, Marc E.
中科院分区：
文献类型：
--
作者：
Clark di Leoni, Patricio;Mininni, Pablo D.;Brachet, Marc E.
在经典湍流中，螺旋度耗尽了非线性并改变了湍流的演化，而在量子湍流中，它的作用还没有完全被理解。本文采用高空间分辨率的Gross-Pitaevskii方程对螺旋量子湍流的自由衰变进行了数值模拟。这种演变与经典流动有显著的相似之处，后者在小尺度上表现出不可压缩动能和螺旋度的双重传递。时空分析表明，这两个量通过开尔文波的非线性激发和随后的声子发射在小尺度上耗散。在衰变开始时，产生的湍流显示出极化的大尺度结构和非极化的静止斑块，使人想起在非常大雷诺数的经典湍流模拟中观察到的那些。
While in classical turbulence helicity depletes nonlinearity and can alter the evolution of turbulent flows, in quantum turbulence its role is not fully understood. We present numerical simulations of the free decay of a helical quantum turbulent flow using the Gross-Pitaevskii equation at high spatial resolution. The evolution has remarkable similarities with classical flows, which go as far as displaying a dual transfer of incompressible kinetic energy and helicity to small scales. Spatiotemporal analysis indicates that both quantities are dissipated at small scales through nonlinear excitation of Kelvin waves and the subsequent emission of phonons. At the onset of the decay, the resulting turbulent flow displays polarized large scale structures and unpolarized patches of quiescence reminiscent of those observed in simulations of classical turbulence at very large Reynolds numbers.