Investigation of flow characteristics in regions of nasal polypoid change

The simulation results showed that Regions A1-A4 were not correlated with the local stagnation points where a locally high level of wall pressure was achieved. They, however, exhibited a very distinctive feature in that the positive wall-normal pressure gradients evaluated at the epithelial surface were persistent at six different flow rates spanning the whole respiration period in these areas. Therefore, the regions where polypoid changes developed were thought to be subject to mechanical irritation of the epithelium constantly via locally accelerating airflow moving towards the surface from the airway. On the contrary, relatively large or small values for local wall shear stress were not correlated with Regions A1-A4.