Atherosclerosis is the most common cardiovascular disease (CVD) causing increased morbidity. Although atherosclerosis is a general disease involving several factors, it preferentially affects the wall of the vessel bifurcations. The use of advanced Computational Fluid Dynamics (CFD) techniques has the potential to shed more light in the further understanding of the causes of the disease and perhaps in its early diagnosis. In this work, a three-dimensional (3D) Fluid Structure Interaction (FSI) study was carried out for a patient specific carotid artery. By considering physiological conditions, first the normal and then with hypertension disease, haemodynamic parameters were evaluated to better understand the genesis and progression of atherosclerotic plaques in the carotid artery bifurcation. Two-way FSI was performed by applying a fully implicit second-order backward Euler differencing scheme using commercial software ANSYS and ANSYS CFX (version 19.0). Arbitrary Lagrangian–Eulerian (ALE) formulation was employed to calculate the arterial response by using the temporal blood response. Due to arterial bifurcation, obvious velocity reduction and backflow formation were observed which decreased shear stress and made it oscillatory at the starting point of the internal carotid artery near the carotid sinus, which resulted in low shear stress. Oscillatory Shear Index (OSI) signifies oscillatory behaviour of artery wall shear stress. By using anatomically realistic 3D geometry and representative physiological conditions, the results obtained for shear stress are more acceptable. Comparison of the results of this study with those in the published literature shows that the regions with low wall shear stress and with OSI value greater than 0.3 pose potential risk to the development of plaques. It was observed that haemodynamics of the carotid artery was very much affected by the geometry and flow conditions. Furthermore, regions of relatively low wall shear stress were observed post stenosis, which is a known cause of plaque development and progression.

动脉粥样硬化是引起发病率增加的最常见的心血管疾病（CVD）。尽管动脉粥样硬化是一种涉及多种因素的一般疾病，但它会优先影响血管分叉壁。先进的计算流体动力学（CFD）技术的使用有可能在进一步了解疾病的原因以及也许在其早期诊断中提供更多的启示。在这项工作中，针对患者特定的颈动脉进行了三维（3D）流体结构相互作用（FSI）研究。通过考虑生理条件（首先是正常疾病，然后是高血压疾病），评估了血流动力学参数，以更好地了解颈动脉分叉的动脉粥样硬化斑块的发生和进展。通过使用商业软件ANSYS和ANSYS CFX（版本19.0）应用完全隐式的二阶反向Euler差分方案来执行双向FSI。采用任意的拉格朗日-欧拉（ALE）公式通过使用时间性血液反应来计算动脉反应。由于动脉分叉，观察到明显的速度降低和回流形成，这降低了切应力并使其在颈内窦附近的颈内动脉起点处振荡，从而导致低切应力。振荡剪切指数（OSI）表示动脉壁剪切应力的振荡行为。通过使用解剖学逼真的3D几何形状和代表性的生理条件，获得的剪应力结果更加可接受。该研究结果与已发表文献的结果比较表明，壁切应力低且OSI值大于0.3的区域对斑块的形成具有潜在风险。观察到颈动脉的血流动力学受几何形状和流动条件的影响很大。此外，狭窄后观察到壁切应力相对较低的区域，这是斑块发展和进展的已知原因。