报告地点：行健楼学术活动室526
邀请人：王雨顺教授
摘要：We introduce a novel computational framework designed to explore the dynamicinteractions between fluid and solid particles or structures immersed in a viscous fluid medium. This innovative framework harnesses the power of the phase-field-embedding method, inwhich each solid component, whether rigid or elastic, is characterized by a volume-preservingphase field. The unified velocity within the fluid-solid ensemble governs the movementof both solid particles and the surrounding fluid, specifically for passive particles. Activeparticles, however, are not only influenced by this unified velocity but are also driven bytheir self-propelling velocities. To capture exclusive volume interactions among particlesand between particles and boundaries, we employ repulsive potential forces at a coarserscale. These forces effectively model repulsion and collision effects. Rigid particles maintainstructural integrity by enforcing a zero velocity gradient tensor within their spatial domains, necessitating the introduction of a constraining stress tensor. In contrast, elastic particles aregoverned by a quasi-linear constitutive equation describing the elastic stress within their domains,allowing for accurate modeling of their deformations. The motion of solid particlesis tracked by monitoring the dynamics of their centers of mass. This approach facilitates thedevelopment of a hybrid, thermodynamically consistent hydrodynamic model applicable toboth rigid and elastic particles. Adhering to the generalized Onsager principle, this modelspans the entire computational domain. To numerically solve this thermodynamically consistentmodel for elastic particles, we present a structure-preserving numerical algorithm.Notably, in the limit of an infinite elastic modulus, this algorithm converges to the one employedfor modeling rigid particles. Finally, we substantiate the effectiveness, accuracy, andstability of our proposed scheme through a series of numerical experiments. These experimentsnot only validate the computational framework but also showcase its capabilities,reinforcing the reliability of our approach.
