We analyze numerically the behavior of a deformable micro-capsule confined in a pipe under a pulsatile flow. The capsule moves and is deformed by the action of a pulsatile flow inside the tube with a non-null mean velocity. This configuration can be found in the nature and in many bioengineering systems where artificial capsules are driven by micro-pumps through micro-channels. The capsule is considered as a thin hyperelastic membrane, which encloses an internal fluid. As it has been demonstrated in the literature, this model represents a wide range of artificial capsules, for example, the alginate-based capsules, typically used in bioengineering applications. A hybrid isogeometric finite element method and boundary element method based on a T-spline discretization and formulated in the time domain is used to solve the mechanical and hydrodynamical equations. The influence of the relative rigidity of the membrane, frequency and amplitude of the pulsatile flow is studied. Results show that the behavior of the capsule differs from steady flows and it depends strongly on the frequency of the flow and mechanical characteristic of the capsule.

我们从数值上分析了在脉动流下封闭在管道中的可变形微囊的行为。胶囊在管内以非零平均速度通过脉动流的作用而移动并变形。这种配置可以在自然界和许多生物工程系统中找到，在这些系统中，人造胶囊由微泵通过微通道驱动。胶囊被认为是包裹内部流体的超弹性薄膜。正如文献所证明的那样，该模型代表了广泛的人造胶囊，例如，通常用于生物工程应用中的基于藻酸盐的胶囊。在时域内采用基于T样条离散化的等几何混合有限元方法和边界元方法求解力学方程和流体力学方程。研究了膜的相对刚度，脉动流的频率和幅度的影响。结果表明，胶囊的性能与稳定流动不同，它在很大程度上取决于流动的频率和胶囊的机械特性。