NUMERICAL MODELLING OF ULTRAFINE PARTICLE DISPERSION FROM INCINERATION PLANT

Particulate emission from anthropogenic sources is a relevant topic for air quality and medical experts. The toxic nature of the particles due to the organic compounds on itself, the ability of ultrafine particles (UFPs) to penetrate in the epithelial cells of the lower respiratory tract, and the oxidative damage effects on DNA, which may increase the risk of cancer, are some of the harmful effects on human health caused by exposure to nanoparticles. In the waste management, incineration represents a favourable technique for reducing the waste volume and recovering its energy content to generate electricity and district heating. However, incinerators have been the subject of strong debate in Western countries, since the waste combustion processes are a source of particle and gaseous emissions (Buonanno et al. 2012). Therefore, it is necessary to characterize their impact in terms of UFPs on the surroundings. Computational Fluid Dynamics (CFD) is increasingly used to identify and characterize the specific emission sources in the areas characterized by high anthropogenic pressure, and assess their impact on air quality. In this work, a numerical scheme based on the non-commercial fully explicit Artificial Compressibility (AC) – Characteristic Based Split (CBS) algorithm (Arpino et al. 2010) was used to solve the one-equation Spalart-Allmaras (SA) turbulence model and a K-theory dispersion model (Moreira and Vilhena 2010), to perform numerical simulations and parametric studies of ultrafine particle dispersion in the surroundings of an incinerator plant. The use of the one equation SA model, allows to save computational resources when complex three-dimensional domains are considered and also offers the possibility to switch to a Detached Eddy Simulation (DES) scheme. The fully explicit algorithm involves a matrix inversion free procedure that offers several advantages, such as low computing requirements even for complex three-dimensional problems and the possibility of simple and efficient parallelization.