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arXiv 2302.03382cond-mat.softphysics.flu-dyn
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液-汽系统三维相分离中的生长机制

Growth regimes in three-dimensional phase separation of liquid-vapor systems

Giuseppe Negro, Giuseppe Gonnella, Antonio Lamura, Sergiu Busuioc, Victor Sofonea

AI总结:

本文利用三维格子 Boltzmann 模拟和多组大尺度数据,揭示液-汽等温相分离仅经历指数 1/2 与 2/3 的动力学和惯性生长阶段,并排除指数为 1 的黏性机制。

摘要:

本文通过三维格子 Boltzmann 模拟研究了液-汽相分离。在以约化物理单位表示长度和时间尺度后,我们结合了若干大型模拟(在 $512^3$ 个节点上)的数据,这些模拟具有不同的黏度、表面张力和温度值,从而得到重标度长度 $\hat{l}$ 作为重标度时间 $\hat{t}$ 函数的单一曲线。我们发现证据表明,在数个时间十年范围内存在动力学和惯性机制,其生长指数分别为 $α_d=1/2$ 和 $α_i=2/3$,并且在 $\hat{t} \simeq 1$ 时发生从 $α_d$ 到 $α_i$ 的交叉。这使我们能够排除三维液-汽等温相分离中存在 $α_v=1$ 的黏性机制的可能性,这与二元流体混合物中的情况不同。文中还进一步深入分析了相分离过程的动力学,并表征了形貌和流动性质,以便为理解相分离过程的动力学提供线索。

英文摘要:

The liquid-vapor phase separation is investigated via lattice Boltzmann simulations in three dimensions. After expressing length and time scales in reduced physical units, we combined data from several large simulations (on $512^3$ nodes), with different values of viscosity, surface tension and temperature, to obtain a single curve of rescaled length $\hat{l}$ as a function of rescaled time $\hat{t}$. We find evidence of the existence of kinetic and inertial regimes with growth exponents $α_d=1/2$ and $α_i=2/3$ over several time decades, with a crossover from $α_d$ to $α_i$ at $\hat{t} \simeq 1$. This allows us to rule out the existence of a viscous regime with $α_v=1$ in three-dimensional liquid-vapor isothermal phase separation, differently from what happens in binary fluid mixtures. An in-depth analysis of the kinetics of the phase separation process, as well as a characterization of the morphology and the flow properties, are further presented in order to provide clues into the dynamics of the phase-separation process.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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