Figure 6.
Velocity profiles for the physiologic case at four time points experiencing high wall motion. The radius plot for the physiologic case is shown with the 4 time points labeled A, B, C, and D. Velocity profiles where taken from the upstream (squares), center (circles) and downstream (triangles) planes in the contracting segment and fit with a quadratic curve (solid line). Upstream and downstream planes were 125 μm from the center plane. (A) time = 0.44 s, R = 55.2 μm, Vr = −20 μm/s (B) time = 1.36 s, R = 59.7 μm, Vr = +10 μm/s (C) time = 3.04 s, R = 53.3 μm, Vr = −20 μm/s (D) time = 4.09 s, R = 56.5 μm, Vr = +14 μm/s. All curve fits resulted in R2>0.99. This illustrates that the velocity profile remains parabolic throughout the simulation, even during periods of severe wall motion. Hence, the Poiseuille assumption remains valid along the axial length of the contracting segment.