Numerical Simulation Of Hemodynamics In Pulmonary Artery Branches

To study the hemodynamics of the Pulmonary artery (PA), a numerical investigation of Newtonian and the non-Newtonian Properties of blood flow was presented. Also fluid-structure interaction (FSI) in bio-bifurcating flow was numerically investigated by finite element method (FEM).Numerical investigation of Newtonian blood analog fluid flow in a 90°curved tube was presented and compared with the experimental results, and made a well agreement. For the reconstructed 3D geometric model of the PA and its branches, employed Womersley velocity as aortic entrance conditions, carried out CFD simulation, then, solved hemodynamic parameters of the PA and its branches in a cardiac cycle, analyzed situation of change of flow field, pressure, wall shear stress(WSS) at different times, and its impact on physiological processes.Then, Numerical investigation of the non-Newtonian Properties of blood flow in a 90°curved tube was also presented and compared with the experimental results, and made a well agreement. For the numerical computation, the carreau model was employed to accommodate the shear thinning behavior of blood. And hemodynamic parameters of the PA and its branches was solved in cardiac cycle,Results:Simulation show that the pressure of the main PA and the branches of the left and right PA were higher during the systolic period than the diastolic period, especially, the right PA and its branches were significantly higher than the left; The blood flow velocity of the main PA and its branches were obvious different, the velocity was much larger at the distal of the right PA than the left; High WSS field formed at the proximal of the right PA before the branches during the systolic. Conclusion:The proximal of the right PA and lower lobe artery were affected by much larger pressure and changed firstly, so the change of morphology and function of this segment will be have more important value to prompt existence of the early PAH. Also the numerical results indicated that significant difference between the Newtonian and non-Newtonian fluid Properties of blood was present. However, the distribution of the velocity, pressure, WSS between the non-Newtonian and Newtonian agreed well.At last, the FSI in PA was simulated. Inter-coupling calculation of structural and fluid analysis was realized, and then the Von Mises Stress and the deformation of the flexible were simulated and discussed, when Von Mises Stress in flexible vessel was apparently bigger, its displacement was greater. Conclusion:The inlet and outlet of the PA were changed firstly, should take more care.