Mixture Model Approach for the Study of the Inner Flow Dynamics of an AdBlue Dosing System and the Characterization of the Near-Field Spray

Selective Catalytic Reduction stands for an effective methodology for the reduction of NOx emissions from Diesel engines and meeting current and future EURO standards. For it, the injection of Urea Water Solution (UWS) plays a major role in the process of reducing the NOx emissions. A LES approach for turbulence modelling allows to have a description of the physics which is a very useful tool in situations where experiments cannot be performed. The main objective of this study is to predict characteristics of the flow of interest inside the injector as well as spray morphology in the near field of the spray. For it, the nozzle geometry has been reconstructed from X-Ray tomography data, and an Eulerian-Eulerian approach commonly known as Mixture Model has been applied to study the liquid phase of the UWS with a LES approach for turbulence modeling. The injector unit is subjected to typical low-pressure working conditions. The results extracted from it comprise parameters that characterize the hydraulic behavior as well as jet intact length. The conclusions drawn from the model depict differences in the flow behavior between the injector three orifices, with an under-prediction of nozzle and spray characteristics of LES formulation with respect to traditional RANS turbulence treatment.