title: Numerical investigation of blood flow in a deformable coronary bifurcation and non-planar branch.
abstract: BACKGROUND
  Among cardiovascular diseases, arterials stenosis is recognized more commonly than the others. Hemodynamic characteristics of blood play a key role in the incidence of stenosis. This paper numerically investigates the pulsatile blood flow in a coronary bifurcation with a non-planar branch. To create a more realistic analysis, the wall is assumed to be compliant. Furthermore, the flow is considered to be three-dimensional, incompressible, and laminar.
  
  
  METHODS
  The effects of non-Newtonian blood, compliant walls and different angles of bifurcation on hemodynamic characteristics of flow were evaluated. Shear thinning of blood was simulated with the Carreau-Yasuda model. The current research was mainly focused on the flow characteristics in bifurcations since atherosclerosis occurs mostly in bifurcations. Moreover, as the areas with low shear stresses are prone to stenosis, these areas were identified.
  
  
  RESULTS
  Our findings indicated that the compliant model of the wall, bifurcation's angle, and other physical properties of flow have an impact on hemodynamics of blood flow. Lower wall shear stress was observed in the compliant wall than that in the rigid wall. The outer wall of bifurcation in all models had lower wall shear stress. In bifurcations with larger angles, wall shear stress was higher in outer walls, and lower in inner walls.
  
  
  CONCLUSIONS
  The non-Newtonian blood vessels and different angles of bifurcation on hemodynamic characteristics of flow evaluation confirmed a lower wall shear stress in the compliant wall than that in the rigid wall, while the wall shear stress was higher in outer walls but lower in inner walls in the bifurcation regions with larger angles.
authors: Faculty of Mechanical Engineering, University of Tabriz, Tabriz, Iran ; Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz Iran.
authors: Seyed Esmail
authors: SE
authors: Razavi
authors: Faculty of Electrical and Computer Engineering, University of Tabriz, Tabriz, Iran.
authors: Amir Ali
authors: AA
authors: Omidi
authors: Faculty of Mechanical Engineering, University of Tabriz, Tabriz, Iran.
authors: Massoud
authors: M
authors: Saghafi Zanjani
keywords: Coronary artery disease; Coronary bifurcation; Elastic wall; Non-planar bifurcation; Numerical investigation; Pulsatile flow