Aortic dissection is related to the separation of the tunica intima from the aortic wall, which can cause blood to flow through the newly formed lumen, thereby further damaging the torn vessel. This type of pathology is the most common catastrophic event that affects the aorta and is associated with complications such as malperfusion. In this work, an idealised, simplified geometric model of Type B aortic dissection is investigated experimentally using particle image velocimetry (PIV) and numerically using computational fluid dynamic (CFD) simulations. The flow characteristics through the true and false lumina are investigated parametrically over a range of tear sizes. Specifically, four different tear sizes and size ratios are considered, each representing a different dissection case or stage, and the experimental and numerical results of the flow-rate profiles through the two lumina in each case, along with the phase-averaged velocity vector maps at mid-acceleration, mid-deceleration, relaminarisation and peak systole, and their corresponding velocity profiles are compared. The experimental and numerical results are in good qualitative as well as quantitative agreement. The flow characteristics found here provide insight into the importance of the re-entry tear. We observe that an increase in the re-entry tear size increases considerably the flow rate in the false lumen, decreases significantly the wall shear stress (WSS) and decreases the pressure difference between the false and the true lumen. On the contrary, an increase in the entry tear, increases the flow rate through the false lumen, increases slightly the WSS and increases the pressure difference between the false and the true lumen. These are crucial findings that can help interpret medical diagnosis and accelerate prevention and treatment, especially in high-risk patients.

主动脉夹层与内膜内膜与主动脉壁的分离有关，这可能导致血液流经新形成的内腔，从而进一步损坏撕裂的血管。这种病理类型是影响主动脉的最常见的灾难性事件，并伴有诸如灌注不足等并发症。在这项工作中，B型主动脉夹层的理想化，简化的几何模型使用粒子图像测速（PIV）进行了实验研究，并使用计算流体动力学（CFD）进行了数值模拟。通过真实和错误的流明的流动特性是在一定的撕裂尺寸范围内进行参数研究的。具体来说，考虑了四种不同的泪液大小和大小比率，每种代表不同的解剖情况或阶段，并分别比较了通过两种腔体的流速分布的实验和数值结果，以及中加速，中减速，再分层和峰值收缩时的相平均速度矢量图，并比较了它们相应的速度分布。实验和数值结果在定性和定量方面都具有良好的一致性。此处发现的流动特性可让您深入了解重入撕裂的重要性。我们观察到，再入泪液尺寸的增加会大大增加假内腔的流速，显着降低壁切应力（WSS）并减小假内腔与真实内腔之间的压差。相反，入口撕裂的增加会增加通过假内腔的流速，稍微增加了WSS，并增加了假内腔和真内腔之间的压力差。这些至关重要的发现可以帮助解释医学诊断并加快预防和治疗，特别是在高危患者中。