Buaria Dhawal, Pumir Alain
Tandon School of Engineering, New York University, New York, New York 11201, USA.
Max Planck Institute for Dynamics and Self-Organization, 37077 Göttingen, Germany.
Phys Rev Lett. 2022 Mar 4;128(9):094501. doi: 10.1103/PhysRevLett.128.094501.
Building upon the intrinsic properties of Navier-Stokes dynamics, namely the prevalence of intense vortical structures and the interrelationship between vorticity and strain rate, we propose a simple framework to quantify the extreme events and the smallest scales of turbulence. We demonstrate that our approach is in excellent agreement with the best available data from direct numerical simulations of isotropic turbulence, with Taylor-scale Reynolds numbers up to 1300. We additionally highlight a shortcoming of prevailing intermittency models due to their disconnection from the observed correlation between vorticity and strain. Our work accentuates the importance of this correlation as a crucial step in developing an accurate understanding of intermittency in turbulence.
基于纳维-斯托克斯动力学的内在特性，即强烈涡旋结构的普遍存在以及涡度与应变率之间的相互关系，我们提出了一个简单的框架来量化极端事件和湍流的最小尺度。我们证明，我们的方法与各向同性湍流直接数值模拟中可获得的最佳数据高度吻合，泰勒尺度雷诺数高达1300。我们还强调了现有间歇性模型的一个缺点，即它们与观测到的涡度和应变之间的相关性脱节。我们的工作强调了这种相关性的重要性，它是准确理解湍流间歇性的关键一步。
