具有复杂界面的三维弹性液滴动力学模拟

Three-Dimensional Numerical Simulation of Dynamics of Elastic Capsules

具有复杂界面特性(如界面弹性、界面抗弯特性等)的弹性液滴(如血液细胞)的动力学行为对理解血流等液滴群流动极其重要。本文采用界面追踪法(Front tracking method)捕捉界面演变,界面有限元考虑界面弹性和抗弯特性,有限差分法求解控制方程,发展了研究复杂界面液滴动力学的直接数值模拟方法。通过模拟球形弹性液滴的变形运动验证了该方法的准确性,进而研究了线性剪切流场中弹性液滴的坦克履带式、摇摆式和翻滚式运动。

Dynamics of capsules with complex membrane mechanics,e.g.elasticity and bending resistance,are essential to understand flow behaviors of blood.Basing on a finite difference-front tracking method,a three-dimensional model was developed to study capsule dynamics.Finite element method was employed to consider membrane elasticity and bending resistance.The model was validated by simulating the deformation of spherical capsules.Using this model,three dynamical states of capsules in a linear shear flow were studied,including tank-treading,swinging and tumbling.