发表机构
INFN（意大利国家核物理研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
通过高分辨率数值模拟分解涡旋与背景分量，揭示二维湍流逆级联中涡旋分量对能谱及科尔莫戈罗夫标度的影响，推导并验证相关平衡关系。
AI 中文摘要
我们通过在中间波数处施加外力的高分辨率数值模拟，研究二维湍流的能量逆级联。为阐明在外力尺度附近产生的涡旋的作用，我们将涡量和速度场分解为涡旋分量与背景分量。尽管涡旋分量仅携带总能量的一小部分，但它对能谱有明显影响，并产生偏离量纲科尔莫戈罗夫标度的现象，而该标度由背景流实现。我们为分解后的场推导了广义冯·卡门-豪斯平衡，并得到一个涉及涡旋与背景速度增量之间三阶关联的关系。模拟结果支持该预测，我们将其解释为与涡旋-背景关联相关的惯性范围通量常数。
英文摘要
We study the inverse energy cascade of two-dimensional turbulence by means of high-resolution numerical simulations forced at intermediate wavenumbers. To clarify the role of vortices generated near the forcing scale, we decompose the vorticity and velocity fields into vortex and background components. Although the vortex component carries only a small fraction of the total energy, it has a clear effect on the energy spectrum and produces deviations from dimensional Kolmogorov scaling, which is realized by the background flow. We derive a generalized von Karman--Howarth balance for the decomposed fields and obtain a relation involving the third-order correlation between vortex and background velocity increments. The simulations support this prediction, which we interpret as a constant inertial-range flux associated with vortex-background correlations.
