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arXiv 2407.12263physics.flu-dyn
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一种无差分守恒相场格子玻尔兹曼方法

A difference-free conservative phase-field lattice Boltzmann method

Chunheng Zhao, Saumil Patel, Taehun Lee

AI总结:

提出无差分守恒相场格子玻尔兹曼方法,结合单流体与CPF-lBM,通过PDF矩求导消除有限差分,高效求解两相流,效率提升47%。

摘要:

我们提出了一种创新的无差分方案,该方案将单流体格子玻尔兹曼方法(lBM)与守恒相场(CPF)格子玻尔兹曼方法相结合,以有效解决大规模两相流体流动问题。无差分方案通过粒子分布函数(PDF)的矩来推导序参数和法向量的导数。我们进一步将表面张力力以连续表面应力形式纳入动量方程,通过修改平衡PDF来消除散度算子。因此,整个计算过程无需任何网格间有限差分格式,表现出更高的效率,使其成为高性能计算应用的理想选择。我们模拟单个静态液滴以评估寄生电流的强度并检验方案的精度。随后,我们引入密度或粘度比,并施加外部体积力分别模拟瑞利-泰勒不稳定性和单个上升气泡的行为。最后,我们采用我们的方法研究单个气泡在泰勒-格林涡中破裂的现象。无差分方案与有限差分方法的比较表明,该方案能够产生准确的结果。此外,基于性能评估,当前方案相比先前方法展现出令人瞩目的47%的效率提升。

英文摘要:

We propose an innovative difference-free scheme that combines the one-fluid lattice Boltzmann method (lBM) with the conservative phase-field (CPF) lBM to effectively solve large-scale two-phase fluid flow problems. The difference-free scheme enables the derivation of the derivative of the order parameter and the normal vector through the moments of the particle distribution function (PDF). We further incorporate the surface tension force in a continuous surface stress form into the momentum equations by modifying the equilibrium PDF to eliminate the divergence operator. Consequently, the entire computation process, executed without any inter-grid finite difference formulation, demonstrates improved efficiency, making it an ideal choice for high-performance computing applications. We conduct simulations of a single static droplet to evaluate the intensity of spurious currents and assess the accuracy of the scheme. We then introduce the density or viscosity ratio and apply an external body force to model the Rayleigh-Taylor instability and the behavior of a single rising bubble, respectively. Finally, we employ our method to study the phenomenon of a single bubble breaking up in a Taylor-Green vortex. The comparison between the difference-free scheme and the finite difference method demonstrates the scheme's capability to yield accurate results. Furthermore, based on the performance evaluation, the current scheme exhibits an impressive $47\% $ increase in efficiency compared to the previous method.

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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