NUMERICAL-ANALYSIS OF STEADY GENERALIZED NEWTONIAN BLOOD-FLOW IN A 2DMODEL OF THE CAROTID-ARTERY BIFURCATION

The stationary flow of blood in a two-dimensional model of the bifurca tion of the human carotid artery is simulated numerically using a fini te element method. The Reynolds number is taken as equal to 300, corre sponding to the value during the end-diastolic phase of the heart cycl e. As constitutive equations, the Newtonian model and the non-Newtonia n power-law and Casson models are used. The chosen model parameters co rresponded with blood. The flow in this geometry is determined by the branching of the artery and the existence of a reversed flow area in t he internal carotid artery. From the results of this problem, we concl ude that the general flow structure is not influenced by the generaliz ed (non-)Newtonian models. However, there are differences that cannot be neglected. First, the generalized Newtonian models result in axial and secondary velocity profiles that have 5-10% lower maximum values c ompared to the Newtonian model. Second, the pressure has higher values in the case of the generalized Newtonian models, especially in the in ternal carotid artery where these models give maximal 25% higher press ure values. Third, along the divider wall, the wall shear stresses are lower for the generalized Newtonian models; near the apex, this diffe rence is maximal 40% in case of the power-law model. The generalized N ewtonian models give higher wall shear stresses along the non-divider wall than the Newtonian model, the maximum difference being 5%. And fo urth, in the internal carotid artery the reversed now area is 10% redu ced by the generalized Newtonian models. In general, the differences a re more pronounced in the case of the power-law model.