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arXiv 2501.11643physics.flu-dyn
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基于扩散界面方法模拟两相流的能量分析

On the Energy Analysis of Two-phase Flows Simulated with the Diffuse Interface Method

Ali Mostafavi, Mohammadmahdi Ranjbar, Vitaliy Yurkiv, Alexander L. Yarin, Farzad Mashayek

AI总结:

本文利用完全耦合 CHNS 方程的相场方法模拟两相流,通过总能量演化分析动能、混合能与耗散关系,并经液滴振荡和毛细丝线破碎基准验证其界面动力学模拟能力。

摘要:

本文采用相场方法(Phase-Field Method,PFM),通过完全耦合的 Cahn-Hilliard-Navier-Stokes(CHNS)方程控制时间演化,以模拟两相流。该方法使总能量泛函最小化,并计入扩散耗散与黏性耗散。文中借助总能量泛函的时间演化,分析动能、混合能与黏性耗散之间的相互作用,从而提出一种新视角。在特定条件下,经典表面能由混合能近似,并对这一替代的准确性进行了严格评估。由 Korteweg 应力张量导出的基于能量的表面张力公式,在捕捉混合能变化方面表现出极高精度。通过液滴振荡和毛细丝线破碎两个基准问题展示了这些概念。主要发现包括:验证了混合能理论适用于大变形界面,并揭示了丝线破碎与液滴振荡过程中不同的能量耗散模式。结果突出表明,基于自由能的 PFM 能够在保持能量守恒的同时,稳健而准确地捕捉复杂界面动力学。

英文摘要:

The Phase-Field Method (PFM) is employed to simulate two-phase flows with the fully-coupled Cahn-Hilliard-Navier-Stokes (CHNS) equations governing the temporal evolution. The methodology minimizes the total energy functional, accounting for diffusive and viscous dissipations. A new perspective is presented by analyzing the interplay between kinetic energy, mixing energy, and viscous dissipation using the temporal evolution of the total energy functional. The classical surface energy is approximated with mixing energy under specific conditions, and the accuracy of this substitution is rigorously evaluated. The energy-based surface tension formulation derived from the Korteweg stress tensor demonstrates exceptional accuracy in capturing variations in the mixing energy. These concepts are demonstrated by considering two benchmark problems: droplet oscillation and capillary thread breakup. Key findings include validating mixing-energy theory for highly deformed interfaces, as well as the discovery of distinct energy dissipation patterns during thread breakup and droplet oscillations. The results highlight the robustness of the free energy-based PFM in accurately capturing complex interfacial dynamics, while maintaining energy conservation.

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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