Analysis of Flow Phenomena in Gastric Contents Induced by Human Gastric Peristalsis Using CFD
Analysis of Flow Phenomena in Gastric Contents Induced by Human Gastric Peristalsis Using CFD
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DOI：
10.1007/s11483-010-9183-y
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发表时间：
2010-12-01
期刊：
影响因子：
3
通讯作者：
Ichikawa, Sosaku
中科院分区：
文献类型：
--
作者：
Kozu, Hiroyuki;Kobayashi, Isao;Ichikawa, Sosaku
本文用计算流体力学方法模拟和分析了人体蠕动引起的胃内流体运动。我们创建了远端胃发生蠕动的二维计算域。利用本研究定义的函数很好地模拟了胃壁在计算域壁上由心房收缩波（ACW）引起的运动。在闭塞区域附近观察到ACW引起的逆流，在最窄的区域达到了约12 min的最高速度。本研究中应用的胃内容物模型的黏度对最高速度几乎没有影响，但对计算域中的速度分布有很大影响。利用数值输出数据计算胃液运动引起的剪切速率。在最闭塞的区域，剪切速率达到了大约20 s（-1）的较高值。剪切速率曲线几乎与流体粘度无关。我们还模拟了当胃壁发生蠕动时，胃消化酶（胃蛋白酶）在模型胃内容物中的传质。可视化模拟结果表明，胃蠕动能够有效地将胃壁分泌的胃蛋白酶与胃内液体混合。
This paper uses computational fluid dynamics to simulate and analyze intragastric fluid motions induced by human peristalsis. We created a two-dimensional computational domain of the distal stomach where peristalsis occurs. The motion of the gastric walls induced by an antral contraction wave (ACW) on the wall of the computational domain was well simulated using a function defined in this study. Retropulsive flow caused by ACW was observed near the occluded region, reaching its highest velocity of approximately 12 minis in the narrowest region. The viscosity of the model gastric contents applied in this study hardly affected the highest velocity, but greatly affected the velocity profile in the computational domain. The shear rate due to gastric fluid motion was calculated using the numerical output data. The shear rate reached relatively high values of approximately 20 s(-1) in the most occluded region. The shear rate profile was almost independent of the fluid viscosity. We also simulated mass transfer of a gastric digestive enzyme (pepsin) in model gastric content when peristalsis occurs on the gastric walls. The visualized simulation results suggest that gastric peristalsis is capable of efficiently mixing pepsin secreted from the gastric walls with an intragastric fluid.