Investigation of periodic flow in human bronchus by PIV measurement and numerical simulation

Abstract

Oscillating flow near the first branch of the human bronchus was experimentally and numerically investigated. The investigation was conducted with three different Dean numbers. Dean number was varied by changing curvature of pharynx. Resin bronchial model was employed for the experiments. Velocity distribution was measured by PIV. 3D unsteady numerical simulation was conducted under the same conditions as in the experiment. The velocity and pressure distributions were investigated by the simulation. In the inspiration flow, the results showed the velocity distribution around the first branch is becoming more uniform as the Dean number increases. It is speculated that the incoming flow to the bronchial bifurcation was accompanied by the Dean vortices. These Dean vortices may make velocity distribution uniform. It is considered that the more Dean number increases, the more the velocity distribution becomes uniform.