Biomedical Engineering Reference
In-Depth Information
FIGURE 13.6
A
Velocity vectors
in the left descending artery with
an 80% stenosis (A). Jet flow
developed at the stenosis throat,
inducing a large recirculation
zone distal to the stenosis. The
recirculation zone by the bifurca-
tion upstream is still visible. A
close-up view of the stenosis and
the recirculation zone is shown in
panel B.
Velocity
W
7.206e
−
001
5.405e
−
001
3.603e
−
001
1.802e
−
001
0.000e
+
000
[m s
∧
−
1]
0
0.000
0.000 (m)
0.0015
0.0048
B
Velocity
W
7.206e
−
001
5.405e
−
001
3.603e
−
001
1.802e
−
001
0.000e
+
000
[m s
∧
−
1]
0
0.000
0.000 (m)
X
Y
0.0015
0.0048
With this model, one was able to calculate the velocity, velocity gradient, kinetic energy
(
k
), energy dissipation rate, and many other parameters for every single fluid element (there
are approximately 2.2 million elements in the model). For this particular flow condition, a
no-slip wall boundary condition was used and the inlet velocity waveform mimicked the
temporal changes in the cardiac output waveform during systole. The outflow was consid-
ered to be a pressure outlet. Based on the information obtained from the simulation, shear
stress and pressure distribution in the left coronary artery under normal and stenosis condi-
tions can be estimated directly and then used as an input during
in vitro
experiments to
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