Banks, J. and Bressloff, N.W.
Turbulence modeling in three-dimensional stenosed arterial bifurcations.
ASME Journal of Biomechanical Engineering, 129, (1), . (doi:10.1115/1.2401182).
Under normal healthy conditions, blood flow in the carotid artery bifurcation is laminar.
However, in the presence of a stenosis, the flow can become turbulent at the higher
Reynolds numbers during systole. There is growing consensus that the transitional k
? model is the best suited Reynolds averaged turbulence model for such flows. Further
confirmation of this opinion is presented here by a comparison with the RNG k? model
for the flow through a straight, nonbifurcating tube. Unlike similar validation studies
elsewhere, no assumptions are made about the inlet profile since the full length of the
experimental tube is simulated. Additionally, variations in the inflow turbulence quantities
are shown to have no noticeable affect on downstream turbulence intensity, turbulent
viscosity, or velocity in the k? model, whereas the velocity profiles in the transitional
k? model show some differences due to large variations in the downstream turbulence
quantities. Following this validation study, the transitional k? model is applied in a
three-dimensional parametrically defined computer model of the carotid artery bifurcation
in which the sinus bulb is manipulated to produce mild, moderate, and severe
stenosis. The parametric geometry definition facilitates a powerful means for investigating
the effect of local shape variation while keeping the global shape fixed. While turbulence
levels are generally low in all cases considered, the mild stenosis model produces
higher levels of turbulent viscosity and this is linked to relatively high values of turbulent
kinetic energy and low values of the specific dissipation rate. The severe stenosis model
displays stronger recirculation in the flow field with higher values of vorticity, helicity,
and negative wall shear stress. The mild and moderate stenosis configurations produce
similar lower levels of vorticity and helicity. DOI: 10.1115/1.2401182
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