A new experimental dataset to validate CFD models of airborne nanoparticles agglomeration

The dynamics of airborne nanoparticles undergoing transport, agglomeration and deposition in a chamber is experimentally studied. We consider the case of a small chamber swept by a constant airflow (ReH=14000) laden with nanoparticles at a controlled concentration and particle size distribution (PSD). A high concentration is used so as to make agglomeration significant, both Brownian and turbulent agglomeration occurring in the chamber. We then consider the steady state reached by the aerosol in the chamber, and measure the concentration and PSD fields by means of a scanning mobility particle sizer (SMPS), for two types of aerosol particles (NaCl particles - GMD=45nm - and copper oxide particles – GMD=8nm). Air mean velocity and turbulence parameters are also characterized by means of a two-component LDA system. The obtained experimental data aim at validating CFD models of turbulent two-phase flows where low-inertia particles undergo transport, agglomeration and wall-deposition. The obtained dataset is indeed the first to provide such space-resolved PSD measurements of airborne nanoparticles, together with detailed and well-controlled flow data. The influence of particles morphology on coagulation kinetics is highlighted and documented through additional transmission electron microscopy (TEM) observations.