Pulsated free jets with polydisperse spray injection: Experiments and numerical simulations

In the present contribution, we consider acoustically pulsated free jets with a polydisperse spray injection in an axisymmetrical configuration. The acoustic excitation creates periodical large vortical structures, which are representative of the dynamics of gaseous flows in more complex configurations, and a strong interaction with the injected spray. In this context, we provide a series of detailed experimental measurements using laser diagnostics; we analyze droplet size distributions, associated size-conditioned dynamics and evaporation, for three liquids, leading to various droplet preferential concentrations due to the vortices. Besides the achievements in terms of diagnostics, we use the Eulerian multi-fluid model and dedicated robust numerical schemes in order to conduct simulations in the chosen configuration. Detailed comparisons between numerical simulations and experimental measurements are provided in terms of spray velocity and number density. Size-conditioned preferential concentration of both non-evaporating and evaporating sprays are observed and reproduced by the numerical simulations, which eventually yields a validation of the proposed model.