Effect of Intermittency on Axial Dispersion in an Asymmetrical Oscillatory Flow.

Abstract

Axial dispersion in oscillatory flow is one of the important factors influencing the gas transport during HFO. Recently, the requirements for HFO have become diversified. The mucus clearance is one of the important steps for HFO. It was proven that the difference of flow rates between inspiration and expiration of oscillation was effective for mucus clearance. According to our latest study, the dispersion in an oscillatory flow can be improved by introducing a stationary period right after the diffusing particle experiences the largest movement, because of its lateral mixing effect during the stationary period. In this study, the numerical simulation of gas transport in an asymmetrical oscillatory laminar flow in a straight circular pipe was carried out for improvement of gas transport. The presence of the stationary period enhances axial gas transport in an asymmetrical oscillatory flow, and the maximum ratio of effective diffusivity to molecular diffusivity is double that of sinusoidal oscillatory flow.