We present a two-phase model of platelet aggregation in coronary-artery-sized blood vessels. The model tracks the number densities of three platelet populations as well as the concentration of a platelet activating chemical. Through the formation of elastic bonds, activated platelets can cohere with one another to form a platelet thrombus. Bound platelets in a thrombus move in a velocity field different from that of the bulk fluid. Stresses produced by the elastic bonds act on the bound platelet material. Movement of the bound platelet material and that of the background fluid are coupled through an interphase drag and an incompressibility constraint. The relative motion between bound platelets and the background fluid permits intraclot transport of individual platelets and activating chemical, allows the bound platelet density to reach levels much higher than the platelet density in the bulk blood, and allows thrombus formation to occur on a physiological timescale, all of which were precluded by our earlier single phase model. Computational results from the two-phase model indicate that through complicated fluid-structure interactions, the platelet thrombus can develop significant spatial inhomogeneities and that the amount of intraclot flow may greatly affect the growth, density, and stability of a thrombus.

中文翻译：

---

血小板聚集的两相混合模型。

我们目前在冠状动脉大小的血管中的血小板聚集的两阶段模型。该模型跟踪三个血小板种群的数量密度以及血小板活化化学物质的浓度。通过形成弹性键，活化的血小板可以彼此粘附形成血小板血栓。血栓中的结合血小板在不同于散装流体的速度场中移动。由弹性键产生的应力作用在结合的血小板材料上。结合的血小板物质的运动和背景流体的运动通过相间阻力和不可压缩性约束而耦合。结合的血小板和背景流体之间的相对运动允许单个血小板在凝块内转运并活化化学物质，可以使结合的血小板密度达到比大量血液中的血小板密度高得多的水平，并允许血栓形成在生理时间尺度上发生，所有这些都被我们较早的单相模型所排除。两相模型的计算结果表明，通过复杂的流体-结构相互作用，血小板血栓可能会形成明显的空间不均匀性，并且血块内血流量可能会极大地影响血栓的生长，密度和稳定性。