论文标题
非牛顿和毛弹性效应在动脉流的模拟中
Non-Newtonian and poroelastic effects in simulations of arterial flows
论文作者
论文摘要
在本文中,我们专注于研究对不同耦合计算模型的流体动力因子的影响,这些计算模型描述了不可压缩的流体与两个对称弹性或毛弹性结构之间的相互作用。流体区域受时间依赖的Navier-Stokes方程的控制;对于结构区域,我们采用两种不同类型的完全动态模型来研究弹性和毛弹性的影响。众所周知,血流在小血管和复杂几何形状的情况下显示出非牛顿特性。一方面,我们使用Carreau-Yasuda模型对血流进行数值实验,以模拟粘度并研究非牛顿血液流变性的影响,以及通过将计算结果与牛顿流体与牛顿流体或弹性结构进行比较,从而模拟非牛顿血液流动性以及对基准容器的毛弹性。另一方面,我们在轴对称狭窄动脉中对血流进行了二维模拟,不仅考虑了非牛顿液特性,还考虑了流体结构的相互作用。这项研究的结果表明,包括速度和压力场,壁剪应力,相对停留时间,位移和过滤速度在内的流动特性受不同模型,几何形状和参数(例如渗透性和Lamé系数)的影响。
In this paper, we focus on investigating the influence on hydrodynamic factors of different coupled computational models describing the interaction between an incompressible fluid and two symmetric elastic or poroelastic structures. The fluid region is governed by time dependent Navier-Stokes equations; while for the structure region, we employ two different types of fully dynamic models to study the effects of elasticity and poroelasticity. It is known that blood flow shows a non- Newtonian property in small vessels and in situations of complex geometries. On one hand, we perform numerical experiments for blood flow using the Carreau-Yasuda model to simulate the viscosity and study the influence of non-Newtonian blood rheology as well as the poroelasticity on a benchmark vessel, by means of comparing computational results with models with Newtonian fluids or elastic structures. On the other hand, we present a two-dimensional simulation of blood flow in an axisymmetric stenosis artery, considering not only the non-Newtonian fluids properties but also the fluid-structure interaction. The results of this study demonstrate that the flow characteristics, including velocity and pressure fields, wall shear stress, relative residence time, displacement and filtration velocity, are affected by different models, geometries and parameters, such as permeability and Lamé coefficients.