A mathematical model for oesophageal swallowing of a food-bolus

The flow of a food-bolus through the oesophagus is investigated by considering a model that involves the study of the axisymmetric peristaltic transport of a power-law fluid through a circular tube of finite length where a single wave is supposed to propagate along the wall. The wall equation of the tube has been taken to fit the natural oesophageal wall contraction that does not involve the expansion beyond the stationary boundary. The spatial, as well as temporal, dependence of pressure has been studied for a fixed time-averaged flow-rate in the laboratory frame of reference. Comparisons are made between the effects of a single wave transport and a train wave transport with an integral number of waves in the train. The effect of the nature of the wave and the power-law index on the pressure distribution along the length of the oesophagus is examined. Computational results for the shear stress distribution along the length of the oesophagus are used to investigate the impact of the single wave propagation vis-a-vis the train wave propagation. (C) 2001 Elsevier Science Ltd. All rights reserved.