Influence of the boundary conditions on aorta blood flow simulations

Simulations of blood flows in the aorta area provide a better understanding of the hemodynamic blood flow mechanism for evaluating the risk of some cardiovascular diseases.An aorta model was reconstructed from magnetic resonance imaging(MRI)images while the blood flow and hemodynamic parameters in the ascending aorta,the descending aorta and the main peripheral arteries were measured using phase contrast MRI(PC-MRI).The boundary conditions affected the flow rate,wall shear stress,averaged wall shear stress and the oscillating shear index.The results show that simulations with zero pressure outlets,simulations with fitted input flows and zero pressure outlets,and simulations with fitted input flow and outflow discharges give quite different results.The input flow variations are mainly related to the local and average wall shear stresses and the oscillating shear index.The outlet flows are strongly related to the outlet boundary conditions.