论文标题

通过相互作用电势形成湍流

Formation of turbulence via an interaction potential

论文作者

Abramov, Rafail V.

论文摘要

在最近的一项工作中,我们提出了一个假设,即通过电势相互作用的颗粒可以产生气体的湍流 - 例如,短范围的原子间电位以及长范围的静电电位。在这里,我们研究了两个粒子的简单模型中提出的湍流形成的力学,这些机制仅通过电势相互作用。遵循动力学理论方法,我们得出了速度矩传输方程的层次结构,然后通过基于高雷诺数条件的新颖闭合将其截断。尽管玻尔兹曼方程的速度矩层次结构的标准封闭导致了可压缩的欧拉和方程式的纳维尔 - 斯托克斯系统,但我们的闭合会导致单独的速度的传输方程,这是由潜在强迫驱动的。从大型层流剪切流开始,我们在数值上模拟了速度传输方程的解,重力,Thomas-Fermi和Lennard-Jones电位以及Vlasov-type型大型平均场电位。在所有研究的场景中,动能的时间平均傅立叶光谱显然表现出Kolmogorov的“五三分之二”的功率衰减率。

In a recent work, we proposed a hypothesis that the turbulence in gases could be produced by particles interacting via a potential - for example, the interatomic potential at short ranges, and the electrostatic potential at long ranges. Here, we examine the proposed mechanics of turbulence formation in a simple model of two particles, which interact solely via a potential. Following the kinetic theory approach, we derive a hierarchy of the velocity moment transport equations, and then truncate it via a novel closure based on the high Reynolds number condition. While standard closures of the velocity moment hierarchy of the Boltzmann equation lead to the compressible Euler and Navier-Stokes systems of equations, our closure leads to a transport equation for the velocity alone, which is driven by the potential forcing. Starting from a large scale laminar shear flow, we numerically simulate the solutions of our velocity transport equation for the electrostatic, gravity, Thomas-Fermi and Lennard-Jones potentials, as well as the Vlasov-type large scale mean field potential. In all studied scenarios, the time-averaged Fourier spectra of the kinetic energy clearly exhibit Kolmogorov's "five-thirds" power decay rate.

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