Lattice Boltzmann Simulation And Analysis Of3D Cerebral Aneurysm Hemodynamic

Cerebral aneurysm is a widespread cerebrovascular diseases, due to its rupture withhigh mortality and disability rate, so it has high risk. At present, stenting is regarded as apromising cerebral aneurysms interventional therapy. It is generally considered thathemodynamic play an important role in aneurysms form, growth and rupture. Therefore,many scholars both at home and abroad study the characteristics of hemodynamics withinthe aneurysm to explore the pathological mechanism and treatment mechanism of cerebralaneurysm.On the other hand, as a new numerical simulation method, the lattice Boltzmann method(LBM) is simple in programming, natural parallelism, easy to handle complex boundary,and thus become a powerful tool for simulating complex flow. In this paper, we takingadvantage of the natural parallelism of LBM, achieve the parallel simulation of3D cerebralaneurysm by CUDA platform.In this paper, the D3Q19model in LBM is applied to parallel simulate thehemodynamics of three-dimensional straight and curved vascular cerebral aneurysms, toinvestigate the influence of non-Newtonian effects on hemodynamics. Firstly, compared thechanges of blood flow in the aneurysm before and after the deployment of stent, we observethe difference of model of Newtonian and non-Newtonian model. It is proved that thedeployment of stent makes the aneurysm flow velocity significantly decreased, the vortexmotion significantly weakened; we found that non-Newtonian effects can weaken the bloodflow and vortex motion. Secondly, discussed the non-Newtonian effect on the velocity andthe wall shear stress(WSS), we found that the non-Newtonian effect can effectively avoidthe overestimation of the maximum WSS, also can avoid overestimating the weakeningeffect of stent on the aneurysm WSS. In addition, we also explored the effect of geometryon the blood flow within the aneurysm. We found that the cerebral aneurysm diameter andneck width play an important role in affecting the hemodynamic in the cerebral aneurysm.It is observed that a large aneurysm size and a large dome-to-neck ratio lead to lower impactand pressure of the blood flow to the brain aneurysm wall. The neck width can significantlyaffect the maximum WSS. The results of numerical analysis in this article can offer somereference to the clinical treatment of cerebral aneurysms.