Acceleration statistics as measures of statistical persistence of streamlines in isotropic turbulence.
Acceleration statistics as measures of statistical persistence of streamlines in isotropic turbulence.
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DOI：
10.1103/physreve.71.015301
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发表时间：
2004-07
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影响因子：
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通讯作者：
S. Goto;D. Osborne;J. C. Vassilicos;J. Haigh
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文献类型：
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作者：
S. Goto;D. Osborne;J. C. Vassilicos;J. Haigh
我们引入速度Vs的停滞点作为一种手段来表征和测量的流线的统计持久性。利用理论论证，直接数值模拟（DNS），和运动学模拟（KS）的三维各向同性湍流的不同比例的内部和外部长度尺度L/η的自相似范围，我们表明，存在一个框架，其中平均Vs = 0，即均方根值的加速度，湍流速度，和Vs与La '/u' 2近似相关（V's/u '）（L/eta）（2/3+q），并且V's/u'近似（L/eta）q，其中在Kolmogorov湍流中q = -1/3，在当前DNS中q = -1/6，在我们的KS中q = 0。统计持久性假说与Tennekes清扫假说密切相关。
We introduce the velocity Vs of stagnation points as a means to characterize and measure statistical persistence of streamlines. Using theoretical arguments, direct numerical simulations (DNS), and kinematic simulations (KS) of three-dimensional isotropic turbulence for different ratios of inner to outer length scales L/eta of the self-similar range, we show that a frame exists where the average Vs = 0 , that the rms values of acceleration, turbulent fluid velocity, and Vs are related by La'/u'2 approximately (V's/u')(L/eta)(2/3+q) , and that V's/u' approximately (L/eta)q with q = -1/3 in Kolmogorov turbulence, q = -1/6 in current DNS, and q = 0 in our KS. The statistical persistence hypothesis is closely related to the Tennekes sweeping hypothesis.