The aim of the project ElekSim is to include electrostatic deposition and discharging effects for electret filter media in the simulation software GeoDict. Therefore, the relevant separation mechanisms were integrated and numerically validated for single fibres and simple geometries with computational fluid dynamics (CFD) simulations. For more complex structures, simulations on microtomography scans were compared with experiments, yielding good agreement for suitable parameters for the surface charge density and charge distribution on the fibres. Finally, the ageing behaviour of electret filter media under loading with various aerosols was experimentally characterized and implemented in the software.

Understanding the agglomeration of nanoparticles through evaporation-induced assembly is a key process, highly desirable for manufacturers in powder technology. In this study, we evaporate aerosol droplets of monodisperse size containing monodisperse or bi-disperse copolymer nanoparticles of different sizes and shapes. We observe that as the evaporation rate (K) increases, the degree of buckling increases (i.e. the shape transitions from spherical to deformed to dimpled to donut shapes). Moreover, the degree of buckling of dried microparticle increases with increases in the diffusional motion of the nanoparticles while keeping K constant. A similar observation is found for a binary mixture of nanoparticles.

High-voltage electric transmission lines are subject to mechanical stress, weather conditions, atmospheric processes, and pollution, which affect the insulators. Particulate deposits cause inadequate insulation, flashover and failures. A model is being developed at RSE that predicts insulator contamination events through different thermodynamic, meteorological and atmospheric chemistry conditions. Chemical and microphysical characterization, along a vertical profile, of total suspended particulate and of insulator deposits, and source apportionment, were carried at a site of the Italian National Electricity System, aimed at providing experimental datasets for model predictions validation. Results and linkages with sources and weather conditions are discussed in this contribution.

Indoor air quality is a growing concern for both industrial workers and the general population, especially due to pollution and the Covid pandemic. CFD simulations are widely used to assess aerosol dispersion and its impact on air quality. This study investigates aerosol deposition, focusing on the impact of modelling and numerical choices, and more specifically on the Lagrangian tracking schemes. A detailed study highlights how these parameters influence deposition fractions. Recommendations are provided for improving CFD simulations of applied dispersion studies that are numerous especially since the Covid pandemic.