Peristaltic Transport of a Rheological Fluid: Model for Movement of Food Bolus Through Esophagus

TL;DR

This paper develops a mathematical model using lubrication theory to analyze the peristaltic transport of non-Newtonian fluids, like food bolus, through the esophagus, considering wave shapes and tube lengths.

Contribution

It introduces a new model for non-Newtonian peristaltic transport in the esophagus, accounting for arbitrary wave shapes and analyzing flow variables.

Findings

Flow velocity and pressure are highly sensitive to the flow index 'n'.

Wave train propagation is more effective than single wave for continuous transport.

The model is suitable for low Reynolds number conditions.

Abstract

Fluid mechanical peristaltic transport through esophagus has been of concern in the paper. A mathematical model has been developed with an aim to study the peristaltic transport of a rheological fluid for arbitrary wave shapes and tube lengths. The Ostwald-de Waele power law of viscous fluid is considered here to depict the non-Newtonian behaviour of the fluid. The model is formulated and analyzed with the specific aim of exploring some important information concerning the movement of food bolus through the esophagus. The analysis has been carried out by using lubrication theory. The study is particularly suitable for cases where the Reynolds number is small. The esophagus is treated as a circular tube through which the transport of food bolus takes places by periodic contraction of the esophageal wall. Variation of different variables concerned with the transport phenomena such as pressure, flow velocity, particle trajectory and reflux are investigated for a single wave as well as for a train of periodic peristaltic waves. Locally variable pressure is seen to be highly sensitive to the flow index `n'. The study clearly shows that continuous fluid transport for Newtonian/rheological fluids by wave train propagation is much more effective than widely spaced single wave propagation in the case of peristaltic movement of food bolus in the esophagus.