Efficient and accurate simulations of deformable particles immersed in a fluid using a combined immersed boundary lattice Boltzmann finite element method
Efficient and accurate simulations of deformable particles immersed in a fluid using a combined immersed boundary lattice Boltzmann finite element method
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DOI：
10.1016/j.camwa.2010.03.057
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发表时间：
2011-06-01
影响因子：
2.9
通讯作者：
Raabe, D.
中科院分区：
文献类型：
--
作者：
Krueger, T.;Varnik, F.;Raabe, D.
初始球形胶囊的变形，自由悬浮在简单剪切流中，可以在小变形的限制下进行分析计算[D. Barthes-Biesel，J.M. Rallison，自由悬浮在线性剪切流中的胶囊的时间相关变形，J. Fluid Mech。 113（1981）251-267]。这些解析近似被用来研究网格细分方法、空间分辨率和浸入边界法的离散δ函数对耦合浸入边界格子Boltzmann有限元法获得的数值结果的影响。对于胶囊膜的描述，有限元方法和 Skalak 本构模型 [R. Skalak、A. Tozeren、R.P. Zarda、S. Chien，红细胞膜的应变能函数，Biophys。 J.13(1973)245-264]已被采用。我们的主要目标是研究所提出的小分辨率模型，为有效而准确地模拟浸入流体中的多个可变形粒子提供坚实的基础。我们得出的结论是，膜网格的细节（例如镶嵌方法和分辨率）仅发挥次要作用。流体动力学分辨率，即离散δ函数的宽度，可以显着影响模拟的准确性。 δ函数的离散化引入了人工长度尺度，有效地改变了胶囊的半径和变形能力。我们讨论了在保持高精度的同时减少浸入流体中的可变形物体的模拟计算时间的可能性。 (C) 2010 Elsevier Ltd. 保留所有权利。
The deformation of an initially spherical capsule, freely suspended in simple shear flow, can be computed analytically in the limit of small deformations [D. Barthes-Biesel, J.M. Rallison, The time-dependent deformation of a capsule freely suspended in a linear shear flow, J. Fluid Mech. 113 (1981) 251-267]. Those analytic approximations are used to study the influence of the mesh tessellation method, the spatial resolution, and the discrete delta function of the immersed boundary method on the numerical results obtained by a coupled immersed boundary lattice Boltzmann finite element method. For the description of the capsule membrane, a finite element method and the Skalak constitutive model [R. Skalak, A. Tozeren, R.P. Zarda, S. Chien, Strain energy function of red blood cell membranes, Biophys. J. 13 (1973) 245-264] have been employed. Our primary goal is the investigation of the presented model for small resolutions to provide a sound basis for efficient but accurate simulations of multiple deformable particles immersed in a fluid. We come to the conclusion that details of the membrane mesh, as tessellation method and resolution, play only a minor role. The hydrodynamic resolution, i.e., the width of the discrete delta function, can significantly influence the accuracy of the simulations. The discretization of the delta function introduces an artificial length scale, which effectively changes the radius and the deformability of the capsule. We discuss possibilities of reducing the computing time of simulations of deformable objects immersed in a fluid while maintaining high accuracy. (C) 2010 Elsevier Ltd. All rights reserved.