Pressurised metered dose inhalers (pMDI) are the most widely used aerosol delivery devices
to treat asthma and COPD due to its unique ability to produce numerous inhalable droplets.
However the mechanism leading to droplet generation is elusive, mainly due to small length
scales and short time scale, causing experimental difficulties to obtain flow information.
Such lack of insight has - to date - limited predictive capability of theoretical approaches and
impeded device optimisation. The main aim of this research is to improve understanding of
the thermo-fluid dynamic processes leading to droplet generation by constructing validated
numerical models to predict pMDI aerosol characteristics as a function of device geometry
and formulation composition.
The thesis presents a systematic study of existing two-phase flow models to predict the flow
conditions and the rate of propellant flow through a pMDI actuator: the homogeneous
equilibrium model (HEM), the slip equilibrium model (SEM) and the homogeneous frozen
model (HFM). [Continues.]
A Doctoral Thesis. Submitted in partial fulfillment of the requirements for the award of Doctor of Philosophy of Loughborough University.