论文标题
各向同性湍流中普遍缩放的出现
Emergence of universal scaling in isotropic turbulence
论文作者
论文摘要
传统上，湍流的普遍特性与很高的雷诺数字有关，但最近的工作表明，衍生统计中的幂律的发作发生在不温和的微观雷诺数为10的阶数，相应的指数与惯性范围的结构在很高的Reynolds数字上的功能一致。在本文中，我们使用精确的均质和各向同性湍流的直接数值模拟来确定具有不同强迫机制的一系列初始条件的结果。我们还表明，横向速度梯度的力矩比纵向矩的缩放指数更大，这证实了过去的结果比后者更间歇性。
Universal properties of turbulence have been associated traditionally with very high Reynolds numbers, but recent work has shown that the onset of the power-laws in derivative statistics occurs at modest microscale Reynolds numbers of the order of 10, with the corresponding exponents being consistent with those for the inertial range structure functions at very high Reynolds numbers. In this paper we use well-resolved direct numerical simulations of homogeneous and isotropic turbulence to establish this result for a range of initial conditions with different forcing mechanisms. We also show that the moments of transverse velocity gradients possess larger scaling exponents than those of the longitudinal moments, confirming past results that the former are more intermittent than the latter.
