Heterogeneous gap size distribution. Based on experimental data (A-B), 2 different architectures were designed with a subset (the core) of more tightly packed platelets at the front (C) or in the center (D) of the hemostatic plug. The smallest gaps are 200 and 10 nm between white and gray platelets, respectively. In all cases, the inlet vessel velocity is modeled like a pressure-driven parabolic profile with a maximum velocity of 2 mm/s. (E) Sample regions in a prethrombus area, behind core platelets (gray) and shell platelets (white) with their respective computed velocity magnitudes. (F) Average intrathrombus plasma velocity computed for geometries with the core in the front (black) or middle (red). Platelet packing density, but not the core location, determines the average velocity between platelets.