Transient Atomization Modeling and Optimal Design of a Medical Air-Compressing Nebulizer

Abstract

This paper studies three-dimensional transient flow characteristics of a medical air-compressing nebulizer which is widely used to treat respiratory diseases in the medical field. The transient atomization process of air and water was numerically simulated and reproduced by solving Navier-Stokes equations, turbulent transport equations, the volume of fluid (VOF) model, and discrete phase model (DPM). The water volume fraction inside the nebulizer was simulated and demonstrated under different time. Besides, to better the working performance of the nebulizer, the effects of different working parameters such as different orifice diameters, length of the outflow pipe, and air velocity on the secondary atomization were also studied and discussed. It was found that the most suitable diameter of the orifice for this air-compressing nebulizer is 1.0 mm. Most suitable length of the outflow pipe and the air velocity for producing small air-water bubbles are 10 mm and 4 m/s, respectively.