Analysis of Unsteady Blood Flow in the Human Aortic Bifurcation

Based on the 3D unsteady Navier-Stokes equations as the governing equations, the blood flow in the human aortic bifurcation was simulated by means of the non-Newtonian blood model with the computational fluid dynamics method. The influence of blood flow characteristic parameter distributions on the formation of atherosclerotic plaques at the feature points within a cardiac cycle was investigated, and a comparison of the wall pressure and wall shear stress parameters was made between the Newtonian blood model and the non-Newtonian blood model. The results show that, compared to the Newtonian blood model, the non-Newtonian blood model is more suitable for the description of real blood flow characteristics. Larger blood stagnation areas, more complex wall pressure and wall shear stress distributions exist around the lateral walls of the bifurcation blood vessels during the systolic cycle, more probably causing deposition of fat particles, platelets and fibrin in the blood vessels which are liable to wall injury and reconstruction, in turn formation of atherosclerotic plaques. However, smaller blood stagnation areas, less changes of wall pressure and wall shear stress distributions happen around the lateral walls of the bifurcation blood vessels during the diastolic cycle, with less influence on the formation of atherosclerotic plaques.