A Comprehensive Numerical Model of Thrombus Embolization: Fluid-Thrombus Interactions Through a Coupled Computational...

Thromboembolic diseases, which account for approximately one-third of global deaths, are characterized by thrombus embolization-the process whereby blood clots undergo cohesive/adhesive fracture under fluid-induced forces. Comprehensive numerical modeling of this multiphysics phenomenon has remained challenging, and robust computational frameworks are scarce. This work substantially advances the state-of-the-art of numerical models of thrombus embolization by presenting a framework that couples Lagrangian non-ordinary state-based peridynamics with Eulerian computational fluid dynamics. The formulation can (i) incorporate complex macroscale constitutive laws for a thrombus, (ii) capture delamination physics between a thrombus and a contacting surface, and (iii) couple thrombus structural dynamics with fluid flow discretized on arbitrary unstructured meshes. The latter capability is achieved through the development of a robust interpolation scheme for fast bi-directional data transfer between polyhedral meshes and peridynamic particle clouds. This also advances the literature of peridynamic coupled fluid numerical models, which are mostly limited to bond-based peridynamics and Cartesian meshes. The framework undergoes rigorous validation through five computationally unique benchmarks. The validated framework is then applied to reproduce reported experimental results of embolization of preformed thrombus within a polycarbonate cylindrical tube under varying flow rates. To demonstrate that the numerical framework can support spatially heterogeneous material properties (a capability absent in other approaches), a synthetic test case is reported. Unlike homogeneous assumptions that always predict leading-edge detachment, heterogeneous material properties enable trailing-edge detachment, thus elucidating this previously unexplained experimental observation.