Liquid transport produced by a cluster of peristaltic contractions in a circular channel
Liquid transport produced by a cluster of peristaltic contractions in a circular channel
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由圆形通道中的一组蠕动收缩产生的液体输送
DOI：
10.1103/physrevfluids.6.093102
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发表时间：
2021
影响因子：
2.7
通讯作者：
Imai Yohsuke
中科院分区：
文献类型：
--
作者：
Oyama Tomoki;Ishida Shunichi;Maeyama Kohei;Miyagawa Taimei;Imai Yohsuke
在人的小肠子中观察到在高脂肪食物后或胃肠道疾病患者的聚集性收缩。我们研究了有限雷诺数和有限收缩宽度（波长）下沿圆形通道传播的蠕动收缩簇所产生的流动。我们使用累积晶格玻尔兹曼方法对牛顿流体进行了计算流体动力学分析，其中通道两端的压力为零。我们表明，集群收缩导致集群上的逆行流动和集群上下游区域的流体捕获。流速与团簇中蠕动波的数量不成正比，特别是在收缩比（振幅）较大的情况下。为了了解潜在的机制，我们模拟了不同长度的通道中孤立收缩产生的流动。孤立收缩产生的压力梯度的大小不会随着通道长度的增加而大幅度减小，从而使流量的减小最小化。当将不同波数的聚集收缩的流量绘制为每波通道长度的函数时，流量崩溃到每个收缩比的单一曲线上。此外，簇状收缩的流速收敛于无限周期收缩的流速。我们还比较了和和的流量特性。
Clustered contractions are observed in the human small intestine after fatty meals or in patients with gastrointestinal diseases. We investigate flow produced by a cluster of peristaltic contractions propagating along a circular channel for a finite Reynolds numberand a finite contraction width (wavelength). We perform a computational fluid dynamics analysis of a Newtonian liquid using the cumulant lattice Boltzmann method where zero pressure is given to both ends of the channel. We show that clustered contractions cause retrograde flow over the cluster and fluid trapping in the upstream and downstream regions of the cluster. Flow rate is not proportional to the number of peristaltic waves in a cluster, in particular, for large contraction ratio (amplitude). To understand the underlying mechanism, we simulate flow produced by an isolated contraction in channels with different lengths. The magnitude of pressure gradient produced by the isolated contraction does not decrease largely with increasing the channel length, minimizing a decrease in flow rate. When flow rates of clustered contractions with different numbers of waves are plotted as a function of the channel length per wave, the flow rates collapse onto a single curve of each contraction ratio. In addition, the flow rates of the clustered contractions converge to the flow rates of infinitely periodic contractions. We also compare the characteristics of the flow rate forandto those forand.