论文标题

循环流体的统计平衡

Statistical Equilibrium of Circulating Fluids

论文作者

Migdal, Alexander

论文摘要

我们正在研究Navier-Stokes方程的无粘性极限,并且发现以前未知的异常术语在哈密顿量,耗散和螺旋度中,可以在此极限上幸存下来并定义了湍流统计。 我们发现负责涡旋表和线条负责的CLEBSCH字段的各种拓扑非平地配置。特别是,发现了一个稳定的涡旋表系列,但其异常耗散消失了,$ \sqrtν$。 引入了我们称之为Kelvinons的拓扑稳定的固定奇异流。他们在环路$ c $周围有一个保守的速度循环$γ_α$,而另一个$γ_β$,用于无穷小的闭环$ \ tilde c $ co $ concircirling $ c $,从而导致有限的螺旋。异常耗散的限制有限,我们通过分析进行计算。 Kelvinon负责速度循环的渐近PDF尾巴,\ textbf {完全匹配的数值模拟}。 循环pdf作为回路形状的功能的环方程得出和研究。该方程式为\ textbf {恰好}等效于循环空间中的schrödinger方程,粘度$ν$扮演着普朗克常数的角色。 Kelvinons是WKB限制$ν\ rightarrow 0 $的循环方程的固定点。 Kelvinons的异常Hamiltonian包含一个大参数$ \ log \ frac {|γ_β|}ν$。该参数的主要力量可以概括,从而导致熟悉的渐近自由,例如QCD。特别是,所谓的多重尺度标准定律如QCD所示,是由对数的力量所修改的。

We are investigating the inviscid limit of the Navier-Stokes equation, and we find previously unknown anomalous terms in Hamiltonian, Dissipation, and Helicity, which survive this limit and define the turbulent statistics. We find various topologically nontrivial configurations of the confined Clebsch field responsible for vortex sheets and lines. In particular, a stable vortex sheet family is discovered, but its anomalous dissipation vanishes as $\sqrtν$. Topologically stable stationary singular flows, which we call Kelvinons, are introduced. They have a conserved velocity circulation $Γ_α$ around the loop $C$ and another one $Γ_β$ for an infinitesimal closed loop $\tilde C$ encircling $C$, leading to a finite helicity. The anomalous dissipation has a finite limit, which we computed analytically. The Kelvinon is responsible for asymptotic PDF tails of velocity circulation, \textbf{perfectly matching numerical simulations}. The loop equation for circulation PDF as functional of the loop shape is derived and studied. This equation is \textbf{exactly} equivalent to the Schrödinger equation in loop space, with viscosity $ν$ playing the role of Planck's constant. Kelvinons are fixed points of the loop equation at WKB limit $ν\rightarrow 0$. The anomalous Hamiltonian for the Kelvinons contains a large parameter $\log \frac{|Γ_β|}ν$. The leading powers of this parameter can be summed up, leading to familiar asymptotic freedom, like in QCD. In particular, the so-called multifractal scaling laws are, as in QCD, modified by the powers of the logarithm.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源