Dissecting the performance of a jet nebulizer: The effect of changing design parameters and operating conditions

Abstract

Gas-powered jet nebulizers deliver medications to treat acute and chronic respiratory diseases. Several authors have found large variations in the performance of these nebulizers, and despite numerous attempts, deposition efficiency remains low for both adults and pediatrics. Using a Sympatec laser diffraction system and computational fluid dynamics (CFD) simulations with SolidWorks Flow Simulations and Ansys Fluent, this study uses a comparative analysis to explore the influence of supply air pressure, nozzle orifice diameter, and baffle geometry on jet nebulizer performance. Performance was quantified using critical performance metrics including vacuum levels driving aerosolization rate, Mass Median Aerodynamic Diameter (MMAD), and aerosolization time. Preliminary findings suggest that the authors’ 2.54 mm wide, semi-conical bar baffle may produce superior vacuum levels, and surpasses the performance of the leading commercial bar baffle geometry, the SideStream, with a smaller MMAD (1.7 versus 2.3 microns). The study confirms the predicted relationship between supply pressure and nebulizer performance: higher pressure improves airflow rates, jet velocities, and aerosol characteristics, and reduces aerosolization times. Additionally, a larger nozzle orifice diameter increases airflow rates and promotes better aerosol characteristics, highlighting a direct correlation between orifice size and nebulizer performance. This work underscores the importance of expanding research in nebulizer performance beyond the traditional focus on testing paired nebulizer/compressor systems.

Copyright © 2024 American Association for Aerosol Research

Graphical Abstract

Editor:

• Darragh Murnane

Acknowledgements

Several students have contributed to this research effort through class and capstone projects. For experimental vacuum testing, we acknowledge the contributions of the students in the MCET-535-2205 course, especially Mikel Combs. With preliminary modeling and simulations, we acknowledge the contributions of Virag Pareshkumar Patel and Julia Klimek. For nebulizer performance, we acknowledge Lucas VanDee and Andrew Colautto. For the generation of the 3D prints we acknowledge Irtaza Razvi.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The author’s time to complete this review was generously supported by their institution.