NUMERICAL INVESTIGATION OF BLOOD FLOW IN A STENOTIC ARTERY. TARGET 2: CFD TESTS

Atherosclerosis is an arterial disease, root to most cardiovascular pathologies. In a previous paper, based on the clinical implications of the pathology, we defined a 2-D model of stenotic artery, hypothesised as straight, rigid and cylindrical. The flow rheology was also defined, describing blood as a non-Newtonian, specifically Cassonian, fluid interested by a pulsatile sinusoidal flow, to overcome stiffness. The stenoses were decomposed in elementary shapes: trapezium (as reference one); semi-ellipse; triangle. Single or coupled eccentric plaques were then considered. To compare the dynamics of such different systems two criteria were finally defined: the EAC (Equivalent Area Criterion) and the EDC (Equivalent Dimensions Criterion). A study made 35 possible cases was then proposed. This study has been here carried out numerically. The code employed is Comsol Multiphysics version 3.3, a CFD general purpose program for thermal fluiddynamics simulations. The analysis parameters were: shape and dimensions of the stenoses; single or coupled pathologies; possible mutual locations of the plaques. The results proved that both the blood flow disturbance caused by the stenoses and the peak velocities in the domain are mainly to be attributed to the shape and the height h of the plaque, while the entity of the recirculations downstream of the pathology is more slope-dependent.