A Study For The Stenosis Of Arteria And Its Effect On The Blood Flow

Recently, cardiovascular diseases caused by the stenosis of arteria have become one important problem which hurt human health. Up to now, the cardio-thoracic surgery is the most important treatment for those diseases. The thesis analyzes the effect for the stenosis of arteria on the blood flow based on fluid dynamics, and aims to support the necessary theoretical base and reference data for the cardio-thoracic surgery.In the thesis, the steady-state and unsteady flow simulation for the pulmonary artery and aorta with stenosis has been conducted by using ANSYS CFX commercial code. The stenosis of arteria and its effect on blood flow in the arteries have been investigated by applying streak line, pressure distribution and vibration, wall shear stress, etc. The main conclusions are as follows:(1) Through the steady-state numerical simulations for one pulmonary artery with 6 different kinds of stenosis, it is noted that the velocity at stenosis, the pressure difference between two sides of stenosis, and wall shear stress increased, and a monotone increasing of those parameters was observed with the degree of stenosis. The results also indicated that the stenosis could result in complicated flow phenomena such as vortex, etc, and induced unfavorable effect to the neighboring artery.(2) Through the transient flow simulations for one pulmonary artery with 6 different kinds of stenosis, the velocity, pressure, wall shear stress at stenosis within a cardiac circle have been demonstrated. It is observed that the static pressure, maximum velocity and wall shear stress varied with the time, and the variation range and tendency of those parameters related with the inlet velocity. The results also showed that the vibrations had different amplitude and frequency due to different kind of stenosis of arteria.(3) The results of steady-state numerical simulation for the aorta showed that the visualization of the hemodynamics parameters can be realized by using CFD method, and could provide necessary data for blood flow diagnosis. It is noted that the stenosis of arteria changed the flow-rate distribution, pressure distribution, wall shear stress, etc.(4) The transient numerical simulation result for the aorta showed the information of blood flow in detail, and the hemodynamics parameters such as static pressure, wall shear stress, etc, and their varieties within a cardiac cycle.