Applications of FSI for Cardiovascular Haemodynamics - Computational Hemodynamics: Theory, Modelling and Applications - page 254

Fig. 8.20 Geometry configuration of the idealized artery model. h indicates vessel wall thickness,
D stands for vessel diameter, and R for branch curvature. LM , left main stem; LAD , left anterior
descending; LCx , left circumflex

Table 8.3 Anatomical dimensions of the idealized model
Length of LM 11.0 mm
Dia. of LM 4.0 mm
Dia. of LAD 3.4 mm
Dia. of LCx 3.0 mm
Rad. of curvature of LAD 42.8 mm
Rad. of curvature of LCx 39.3 mm
Angulation between LM and LAD 159°
Vessel wall thickness 0.4 mm
LM left main stem, LAD left anterior descending, LCx Left circumflex

8.4.2 Mesh Generation and Physiological Boundary Conditions

For each coronary artery model, both fluid and structural domains were meshed
with hexahedral cells. A near wall grid refinement was imposed on each model to
provide better resolution for near wall quantities. Mesh results for the fluid and
structural domain of the image-based model and the idealized model ( θ = 90°) are
depicted in Fig. 8.21 . Since it is difficult to obtain the outer wall boundary of the
artery from CT images, the vessel wall was artificially constructed with a constant
thickness (Colombo et al. 2010) h = 0.4 mm. Although arterial wall is a compos-
ite tissue comprised of collagen fibers, its structural properties were simplified by
adopting a nine parameter Mooney-Rivlin hyperelastic model (Koshiba et al. 2007)
due to lack of in vivo data.
The inlet and outlet boundary conditions shown in Fig. 8.22a are based on a
physiological pulsatile flow rate and pressure at the aorta (Nichols et al. 2011),
reconstructed using a Fourier series in Matlab (Math Works Inc., Natick, MA,