Effect of Parenchymal Tethering on the Steady Propagation of a Liquid Plug in a Flexible Airway Model

Surface tension on an air-liquid interface induces liquid flows, which may cause the lung’s airways to close due to the formation of a liquid plug as a result of drainage of the liquid lining coating the airways. Formation of the plug occurs more frequently when lung-surfactant availability is reduced. [1] Mechanical stresses due to fluid motion cause pulmonary epithelial cells to be damaged. [2, 3] Our previous studies for plug propagation in a rigid wall channel show that mechanical stresses are significantly large in the front transition region of the plug compared to the rear transition region. [7, 8] Pulmonary airways are flexible tubes which are surrounded by elastic parenchyma. In this study, the steady propagation of a liquid plug in a flexible tube is investigated numerically and mechanical stresses acting on the epithelial cells are estimated.