| There is more and more evidence that hemodynamic factors play an important role in the development of the arterial atherogenesis, but even up to now, the specific role of the hemodynamic factors is not well understood yet, therefore further research work of revealing the biomechanical mechanism of atherosclerosis is helpful and necessary to learn its pathology and occurrence, which is very important in biofluid dynamics and is closely related to the development of the biofluid dynamics in theory and numerical simulation, the investigation of coronary circulation rules of human cardiovascular system and the further study of occurrence mechanism of cardiovascular diseases, so is of great significance in both scientific research work and realistic application.To study the effect of the hemodynamic factors on the atherogenesis, a series of spatial 3D asymmetric geometric models of coronary artery were built up in this paper. By FEM, the numerical simulation was carried out according to such models, many important hemodynamic variables, such as the tempo-spatial velocity field at every cross section of the artery, the pressure distribution, the secondary flow and the WSS (wall shear stress) at the specific areas were obtained, which will help understand the biomechanics of coronary atherosclerosis furtherly.Many investigators studied the stenotic artery by means of 2 dimensional models, which can only simulate the planar pulsatile waves and got, to some extent, some general results of the blood flow without considering the secondary flow and the reality of physiological conditions. In this paper, 3D spatial asymmetric conditions and real physiological conditions were introduced both in the geometric models and the biomechanical models. The stenosis degree and the bifurcation angel can vary at will according to any requirements specified, the universal program was set up, which can be developed into an individual oriented, real-time and clinically practicalprogram to provide more valuable reference for the surgeon in the clinical diagnosis and disease prediction.To construct geometric models, the main stem and the branches of coronary artery are assumed to develop along the surface of a sphere which simulates a heart body so as to obtain more accurate spatial 3D asymmetric descriptive models for the simulation of the coronary artery. By this method, 3 generations of the coronary branches can be got to simulate more accurate models of coronary vasculature. For simplicity, these assumptions are followed in the simulation :1) The coronary artery is modeled as rigid tube with constant cross section;2) the blood is assumed as viscous incompressible Newtonian fluid without weight;3) the blood flow is developing laminar and becomes fully developed at far downstream.To simulate the nonlinear pulsatile waves propagating in coronary artery, transient analysis was utilized in numerical simulation. One cardiac cycle is divided into 50 parts in the transient analysis to accurately simulate the continuous pulsatile blood flow in the coronary artery, the hemodynamic parameters of the atherosclerotic and the controlled models at each of the 50 moments were computed in accordance with the physiological condition.Compared with the observed result in clinical experience, atheroma often occurs at the place where the WSS is greater and less, this experience is corroborated by the result obtained in the numerical simulation, that is to say, where the higher or the lower the WSS is, where it is more possible for atherosclerosis to take place. The peak values of the WSS appear at the edge of the bifurcation, so the patients should be on the stick for preventing the development of the atherogenesis.Many computational results were obtained and can provide the inner hemodynamic situation at each moment of the cardiac cycle and each specified position of the coronary bifurcation for learning the severity of the atherosclerosis in the coronary artery. The hemodynamical variables and the visible flow conditio...
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