In this paper, effects of stationary contraction on mixing and transport of a non-Newtonian fluid in the small intestine are analyzed theoretically. A semi-analytical method is developed to solve the governing equations of fluids flow in the intestine using lubrication theory. Results indicate that the stationary contraction helps in conferring two functions – (1) shearing of the contents, and (2) bidirectional transport over a short distance. The flow resulting from contraction is symmetric and occurs in both the directions; however, they do not lead to a net flow rate in one direction. The amount of shearing developed during such flows is reflective of their mixing ability. The effort of such peristalsis is largely determined by the flow behavior index; where energy requirements of developing similar shearing forces are higher for dilatants and lower for pseudoplastics. Flow is sensitive to frequency of contraction, luminal occlusion and wavelength of the contraction.

中文翻译：

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小肠静止性收缩对消化的影响

本文从理论上分析了静止收缩对非牛顿流体在小肠中混合和运输的影响。开发了一种半解析方法，利用润滑理论求解肠道中流体流动的控制方程。结果表明，静止收缩有助于赋予两个功能——（1）内容物的剪切，和（2）短距离的双向运输。收缩产生的流动是对称的，并且发生在两个方向上；但是，它们不会导致一个方向的净流量。在这种流动过程中产生的剪切量反映了它们的混合能力。这种蠕动的努力很大程度上取决于流动行为指数；其中，产生类似剪切力的能量需求对于膨胀剂较高，而对于假塑性则较低。流量对收缩频率、管腔闭塞和收缩波长敏感。