Aerosols and Atomization
An aerosol consists of microscopically-dispersed solid or liquid particles, which are suspended in air or another gas. It may occur naturally but it is often artificially generated in a wide variety of engineering processes. Relevant examples include fuel injection in gas turbine combustors as well as problems associated to air pollution, indoor air quality, and inhalation.Bioaerosol Transport in Passenger Aircraft:
The commercial aviation industry was strongly affected by the recent COVID-19 pandemic. Aiming to aid the prevention and mitigation of future pandemics, aircraft cabins must be designed
to ventilate effectively any contaminant dispersed in the air, eventually allowing the early detection
of pathogen spreading using bioaerosol sensors.
Aerosol Dispersion and Deposition:
Many physical mechanisms are involved in the transport and deposition of aerosol particles, namely Brownian and turbulent diffusion, turbophoresis, thermophoresis, inertial impaction, gravitational settling, electrical forces, as well as the effects of surface roughness and particle interception. The inherent complexities make theoretical modeling extremely difficult when aiming to deal with real applications, such as the deposition of particles in gas turbines components or in the human respiratory tract.
Liquid Atomization:
A liquid may be reduced to minute droplets or a fine spray via atomization. For injection in a crossflow, the disintegration process of liquid columns is significantly affected by the liquid injection angle and, to a lesser extent, by the liquid-to-air momentum flux ratio. Crucial knowledge about the resulting spray characteristics may be experimentally obtained with the use of interferometric techniques, e.g. shadowgraph, and phase-Doppler anemometry.
Dissertations:
- Bioaerosol Transport and Sensor in Passenger Aircraft, MSc. Thesis in Aerospace Engineering, Instituto Superior Técnico, 2022.
- Developments for the Application of Smoothed Particle Hydrodynamics to Single- and Two-Phase Flows in Medical Inhalers, PhD. Thesis in Mechanical Engineering, Instituto Superior Técnico, 2015.
- Characterization of Sprays Generated by Pressure Atomizers Subjected to Air Crossflows, MSc. Thesis in Mechanical Engineering, Instituto Superior Técnico, 2008 (in Portuguese).
- Study of the Dispersion and Deposition of Medical Aerosols Generated by Dry Powder Inhalers, PhD. Thesis in Mechanical Engineering, Instituto Superior Técnico, 2008 (in Portuguese).
- Development and Optimization of a Combustion Chamber for Gas Turbines, PhD. Thesis in Mechanical Engineering, Instituto Superior Técnico, 2007 (in Portuguese).