Diesel Nozzle Flow and Spray Formation

The main task of the engine 3D CFD simulation is to support combustion design development. New combustion concepts can be analyzed and predicted by detailed thermo-dynamical computation. To achieve this aim many simulation tools are needed: each of them should be capable of reproducing the sensitivities of combustion design parameters through physically based models. The adoption of different nozzle configurations with analogous specific mass flow and load pressure strongly affect mixture and therefore emissions formation. Nevertheless, the relation between local nozzle flow and spray development in the combustion chamber is still a challenging topic with a high improvement potential. The final achievement of the thesis is a technique, which could reproduce the nozzle flow effects on the 3D simulation of engine combustion cycle, together with an advanced physical and statistical treatment of mixture formation process by means of an Eulerian approach. The advantages of the method will be proven on an operative truck engine case, for which a complete set of experimental data is available.