Ozden Kamil, Sert Cuneyt, Yazicioglu Yigit
Department of Mechanical Engineering, Middle East Technical University, Ankara, Turkey.
Proc Inst Mech Eng H. 2020 Jan;234(1):48-60. doi: 10.1177/0954411919884167. Epub 2019 Oct 24.
Pressure fluctuations that cause acoustic radiation from vessel models with concentric and eccentric blunt stenoses are investigated. Large eddy simulations of non-pulsatile flow condition are performed using OpenFOAM. Calculated amplitude and spatial-spectral distribution of acoustic pressures at the post-stenotic region are compared with previous experimental and theoretical results. It is found that increasing the Reynolds number does not change the location of the maximum root mean square wall pressure, but causes a general increase in the spectrum level, although the change in the shape of the spectrum is not significant. On the contrary, compared to the concentric model at the same Reynolds number, eccentricity leads to an increase both at the distance of the location of the maximum root mean square wall pressure from the stenosis exit and the spectrum level. This effect becomes more distinct when radial eccentricity of the stenosis increases. Both the flow rate and the eccentricity of the stenosis shape are evaluated to be clinically important parameters in diagnosing stenosis.
研究了导致具有同心和偏心钝性狭窄的血管模型产生声辐射的压力波动。使用OpenFOAM对非脉动流条件进行大涡模拟。将狭窄后区域的声压计算幅度和空间频谱分布与先前的实验和理论结果进行比较。结果发现，增加雷诺数不会改变均方根壁面压力最大值的位置，但会导致频谱水平普遍增加，尽管频谱形状的变化并不显著。相反，与相同雷诺数下的同心模型相比，偏心会导致均方根壁面压力最大值位置与狭窄出口的距离以及频谱水平都增加。当狭窄的径向偏心度增加时，这种效应变得更加明显。流速和狭窄形状的偏心度均被评估为诊断狭窄的临床重要参数。
