用于剪切流中囊泡动力学的SPH-网格耦合方法
An SPH--mesh Coupling for Vesicle Dynamics in Shear Flow
浏览论文内容
中文总结 AI 辅助
该研究提出SPH与三角化膜网格耦合的计算框架，含四种弯曲能模型，经囊泡平衡与坦克履带运动验证，揭示弯曲模型对剪切流中囊泡的形态与动力学的影响，为相关研究提供准确工具。
中文摘要 AI 辅助
我们提出了一种将光滑粒子流体动力学（SPH）与三角化膜网格耦合的新型计算框架，用于模拟悬浮在流体中的囊泡的动力学。一种新型的界面追踪方法自然地保证了膜的不可渗透性，无需采用粒子反射或反弹边界条件等非物理约束。该膜模型包含四种不同的弯曲能公式，即最小模型、自发曲率（SC）模型、双层耦合（BC）模型和面积差弹性（ADE）模型，为多种生物物理场景提供了通用工具。该框架通过囊泡的平衡形状和坦克履带式运动进行了严格验证，与先前的理论和数值研究显示出极好的一致性。对每种弯曲模型对剪切流中囊泡的倾斜角、旋转频率和形态的影响进行的系统研究揭示了关键物理见解：值得注意的是，自发曲率对稳态取向的影响可忽略不计，但在低约化体积下通过出现具有深收缩的哑铃状形状显著改变旋转动力学；相比之下，BC和ADE模型则诱导出特征性的不对称和 stomatocyte（口形细胞）形态。我们的结果证实，所提出的SPH-网格耦合是探索流体流动中囊泡复杂的、与形状相关的动力学的准确且鲁棒的工具。
英文摘要
We present a novel computational framework that couples smoothed particle hydrodynamics~(SPH) with a triangulated membrane mesh to simulate the dynamics of vesicles suspended in fluids. A novel interface-tracking approach enforces membrane impermeability naturally, without resorting to non-physical constraints such as particle reflection or bounce-back boundary conditions. The membrane model incorporates four distinct bending energy formulations, namely the minimal model, the spontaneous curvature (SC) model, the bilayer couple (BC) model, and the area difference elasticity (ADE) model, providing a versatile tool for diverse biophysical scenarios. The framework is rigorously validated against equilibrium shapes and tank-treading motion of a vesicle, demonstrating excellent agreement with previous theoretical and numerical studies. A systematic investigation into the effects of each bending model on the vesicle's inclination angle, revolution frequency, and morphology in shear flow reveals key physical insights. Notably, spontaneous curvature has a negligible effect on steady-state orientation but profoundly alters rotational dynamics at low reduced volumes through the emergence of dumbbell-like shapes with deep constrictions. In contrast, the BC and ADE models induce characteristic asymmetric and stomatocyte morphologies. Our results establish the proposed SPH--mesh coupling as an accurate and robust tool for exploring the complex, shape-dependent dynamics of vesicles in fluid flows.
