Early Numerical Studies on the Peristaltic Flow through the Pharynx

Abstract

AbstractThe flow through the pharynx from the GPJ to the UES has been numerically investigated with a non‐Newtonian fluid obeying the power law with similar rheological indices to a contrast medium used in videofluroscopy. Flow fields revealed the occurrence of reflux regions in the beginning, being this effect stronger at low entrance pressure, which could be related to abnormal swallowing. As a consequence, the bolus travels preferably along the walls. It has been also observed that the bolus head travels faster than the bolus tail, which indicates that the bolus is elongated. Results from this work can be further used for a rheological characterization of oral nutritional supplements for patients suffering from swallowing disorders.Practical ApplicationsThe flow through the pharynx has been numerically investigated with a non‐Newtonian fluid to get insight about causes leading to abnormal swallowing. Reflux has been observed in the beginning as result of a central stream and two symmetric loops generated along the walls, being this effect at low peristaltic pressure. Velocity fields revealed that the bolus head travels faster than the bolus tail, which is a result of the geometry and conservation of mass. Under these conditions, extensional stresses are generated by the flexion of the pharynx walls. Shear rate fields allowed establishing the shear rate range at which the bolus is subjected along the pharynx, which is useful for the rheological characterization of supplements for patients suffering from swallowing disorders.