Modelling spray and combustion processes in diesel engine by using the coupled Eulerian-Eulerian and Eulerian-Lagrangian method

The focus of this paper is to demonstrate that the existing and developed models, within the coupled approach, are capable for describing spray, combustion and pollutant formation processes. The Eulerian-Eulerian (EE) method, multi-continuum model, is used for spray modelling including the fuel jet disintegration and droplet evaporation processes. The combustion process is modelled by employing the Eulerian-Lagrangian (EL) discrete droplet model (DDM). The EE-EL coupling has been performed by running simultaneous simulations on a separate computational domains with constantly exchanging mass, enthalpy and momentum sources. The calculated results were compared to the available experimental data and to the previously published results. It is concluded that the pressure and temperature traces, energy conversion and the emission trends are well described and a good agreement to the experimental data is observed. The advantage of the presented approach is retaining a high CPU efficiency, characteristic for the EL method, with an increased solution accuracy in the near-nozzle region characteristic for the EE method.