Mathematical Modelling of Swallowing of Viscoelastic Nature Food Through the Oesophagus Affected by Hiatus Hernia

Peristaltic transport of viscoelastic fluid through a divergent tube is studied by approximations of long wavelength and low Reynolds number. This type of study explains the interesting phenomenon of swallowing food bolus through the oesophagus affected by hiatus hernia. The amplitude of peristaltic waves is increase exponentially, the food bolus to be a viscoelastic fluid and the affected oesophagus a diverging tube. The expressions for axial and radial velocities, pressure and reflux limit are obtained. Both cases have been considered when the whole tube diverges and when it diverges only near the end. Another case in which the tube converges near the last end has also been analysed.