Efficiency of the lumped parameter concept and the role of liquid properties in modelling microdroplet evaporation

This paper presents a study of the micro-sized droplets of dodecane, decane and nonane undergoing evaporation under increasing thermal load through a laminar flow reactor. The objective is to use the effective conductivity concept for the liquid phase to explore the droplet internal state during its lifetime and to assess the efficiency of the infinite conductivity (lumped parameter) concept by comparing these concepts with each other and against the experimental data. Another objective of this work is to assess the sensitivity of the process on the liquid phase properties by developing the constant properties effective conductivity model to more enhanced versions and comparing them to the fully numerical one. Extension to higher Reynolds number and higher temperature conditions is also made. While the enhanced models give almost identical predictions to the full numerical version for all conditions examined, the lump model is also found to yield close predictions. Examination of the liquid properties shows that relative to the other properties, accounting for variation in the liquid density is most important.