Lattice Boltzmann Simulation Of Hemodynamics In Cerebral Aneurysms

In cardiovascular diseases, cerebral aneurysm has been paid close attention because of its high morbidity and mortality rate. Application of stents of the clinical management becomes the new light to the treatment of cerebral aneurysms. Currently, hemodynamic mechanism is widely considered to be one of the main factors to lead to the growth and rupture of the cerebral aneurysm. With better understanding of the hemodynamic mechanism, numerical simulation to study on the effects of stent characteristics such as the shape and porosity on the cerebral intra-aneurysmsmal hemodynamics becomes a focus.In recent years, Lattice Boltzmann method (LBM) has been developed to a new numerical simulation method of fluids. It has many advantages compared to traditional numerical methods, such as the simplicity of program, easiness to handle complex boundary, and high efficiency of parallelism. So it is easy to simulate the complex flows, such as porous media, multiphase flow, and chemical reaction system and so on. The combination of Lattice Boltzmann Method with blood flow problem has been proved to be an effective method. Some scholars at home and abroad studied the effects on aneurysmsmal hemodynamics, but literature on problems such as what is the pore size of the stent when there is just no vortex and the effects on blood circulation in the tiny blood vessel around the aneurysm is little.In this paper, the D2Q9 model in Lattice Boltzmann Method is applied to simulate blood flow in the aneurysm and the tiny blood vessel around. The effects of the stent on aneurysmsmal hemodynamics are analyzed on the assumption that blood belongs to Newton flow. Firstly, the changes of blood flow in the aneurysm before and after the deployment of stent are discussed, and it is proved that the deployment of stent makes the velocity of the blood flow decrease and the movement of the vortex weaken obviously. Secondly, with different aneurysm diameter and aneurism orifice diameter, the pore size of the stent when there is just no vortex is simulated and computed. Finally, due to the fact that real aneurysms always grow at the cross of blood vessels, and tiny blood vessels in the cranium are more sensitive to the deployment of the stent, it is necessary to consider the effect of the stent on the blood vessel around. The results of the simulation can offer some reference to the clinical management.