Granular Turbulence in Two Dimensions---Microscale Reynolds Number and Final Condensed States---
Granular Turbulence in Two Dimensions---Microscale Reynolds Number and Final Condensed States---
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二维粒状湍流---微尺度雷诺数和最终凝聚态---
DOI：
10.1142/s0129183112500325
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发表时间：
2012
影响因子：
1.9
通讯作者：
Masaharu Isobe
中科院分区：
文献类型：
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作者：
四竃格久;下川達也;高橋一志;森初果;熊井玲児;中尾朗子;中尾裕則;小林賢介;村上洋一;木俣基;田島裕之;松林和幸;上床美也;荘涛，平岡耕一，小島健一，鬼丸孝博，高畠敏郎;磯野貴之，加茂博道，四竈格久，高橋一志，中尾朗子，熊井玲児，小林賢介， 中尾裕則，村上洋一，山本薫，松林和幸，上床美也，森初果;Masaharu Isobe
从“二维湍流”的角度研究颗粒气体。在准弹性和热力学极限下，我们通过执行大规模（N ~ 1680 万个圆盘）事件驱动的分子动力学模拟，获得了 Kraichnan-Leith-Bachelor 能谱中熵（涡度平方）级联和 -3 指数的明确证据。在这些计算中，熵耗散率显示出与能谱中指数的演化密切相关。基于微尺度的雷诺数的增长证实了熵级联状态是完全发展的湍流状态。此外，在衰减的二维纳维-斯托克斯湍流中类似玻色-爱因斯坦凝聚的凝聚态也出现为长时限内演化的粒状气体的最终吸引子。
Granular gases from the viewpoint of "two-dimensional turbulence" are investigated. In the quasi-elastic and thermodynamic limit, we obtained clear evidence for an enstrophy (square of vorticity) cascade and -3 exponent in the Kraichnan–Leith–Bachelor energy spectrum by performing large-scale (N ~ 16.8 million number of disks) event-driven molecular dynamics simulations. In these calculations, the enstrophy dissipation rate showed a strong relationship with the evolution of the exponent in the energy spectrum. The growth of the Reynolds number based on the microscale confirmed that the enstrophy cascade regime was that of fully developed turbulence. Moreover, a condensed state resembling Bose–Einstein condensation in decaying two-dimensional Navier–Stokes turbulence also appeared as the final attractor of the evolving granular gas in the long time limit.