Diffusion properties of gradient-based lattice Boltzmann models of immiscible fluids
Diffusion properties of gradient-based lattice Boltzmann models of immiscible fluids
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DOI：
10.1103/physreve.71.056702
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发表时间：
2005-05-01
影响因子：
2.4
通讯作者：
Rothman, DH
中科院分区：
文献类型：
--
作者：
Latva-Kokko, M;Rothman, DH
研究了不互溶流体的梯度格子Boltzmann模型的扩散和相分离性质.我们量化的晶格钉扎与模型相关的问题，并提出了一个计划，消除这些文物。界面宽度由单个参数控制，该参数充当逆扩散长度。我们推导出一个充分发展的界面曲线的解析表达式，并表明，如果没有流体被困在这个稳定的分布，接口演变。如果不存在到本体相的连接路径，则流体可以被捕获在竞争相内。这种被捕获的气泡也会向充分发展的界面曲线发展，但质量守恒的约束限制了这种发展。我们还展示了如何小的数值误差导致自发相分离的扩散长度的所有值。
We study the diffusion and phase separation properties of a gradient- based lattice Boltzmann model of immiscible fluids. We quantify problems of lattice pinning associated with the model, and suggest a scheme that removes these artifacts. The interface width is controlled by a single parameter that acts as an inverse diffusion length. We derive an analytic expression of a fully developed interfacial curve and show that interfaces evolve towards this stable distribution if no fluid is trapped. Fluid can become trapped inside a competing phase if no connecting path to the bulk phase exists. Such trapped bubbles also evolve towards the fully developed interfacial curve but constraints on mass conservation limit this development. We also show how small numerical errors lead to spontaneous phase separation for all values of the diffusion length.