论文标题
在二维逆向能量抗湍流中的两粒子相对速度的非kolmogorov缩放
Non-Kolmogorov scaling for two-particle relative velocity in two-dimensional inverse energy-cascade turbulence
论文作者
论文摘要
本文中，我们通过数值检查Lagrangian粒子对的相对分散在二维逆向能量cascade湍流中。 Richardson-Obukhov $ T^3 $相对分离定律的背后，我们发现相对速度的二阶时刻具有时间缩放指数与基于Kolmogorov的现象学的预测不同。结果还表明，相对速度的概率分布函数的时间演变是自相似的。这些发现是通过考虑特殊的初始分离或通过有条件抽样来执行Richardson-Obukhov法律获得的。特别是，我们证明条件抽样消除了分离和相对速度统计的初始分离依赖性。此外，我们证明了条件统计相对于所涉及的参数的变化具有鲁棒性，并且当雷诺数增加时，从采样对删除对的数量减少。我们还讨论了由于条件抽样而获得的见解。
Herein,we numerically examine the relative dispersion of Lagrangian particle pairs in two-dimensional inverse energy-cascade turbulence. Behind the Richardson-Obukhov $t^3$ law of relative separation, we discover that the second-order moment of the relative velocity have a temporal scaling exponent different from the prediction based on the Kolmogorov's phenomenology. The results also indicate that time evolution of the probability distribution function of the relative velocity is self-similar. The findings are obtained by enforcing Richardson-Obukhov law either by considering a special initial separation or by conditional sampling. In particular, we demonstrate that the conditional sampling removes the initial-separation dependence of the statistics of the separation and relative velocity. Furthermore, we demonstrate that the conditional statistics are robust with respect to the change in the parameters involved, and that the number of the removed pairs from the sampling decreases when the Reynolds number increases. We also discuss the insights gained as a result of conditional sampling.
