Thermal effects on internal combustion engines have been always a hot topic. Concretely, temperature influence on the injection systems is still under research. In this work, a homogeneous model named Eulerian Spray Atomization (ESA) is used to simulate Engine Combustion Network (ECN) Diesel Spray A conditions. A new approach is considered for the thermodynamic model of the fuel and gas mixture. Experimentally obtained values of the liquid enthalpy are directly employed in the simulation to determine the temperature, without any need of knowing its heat capacity or expansion coefficient. This allows to accurately study heating and cooling phenomena inside the Diesel nozzle. Results show that two different boundary conditions could be applied at nozzle walls, either fixed temperature value or adiabatic walls, and still obtain good prediction of injection parameters. Also, the effect of fuel temperature has been investigated. For Spray A conditions, nozzle and spray parameters are the same regardless the fuel temperature. Nevertheless, fluid properties (density, velocity.. .) inside the nozzle significantly change; which means that these type of models could serve in future for cavitation erosion or coking studies.

Gimeno, J.; Marti-Aldaravi, P.; Alarcón-Herrera, MY. (2017). Numerical simulation of needle movement nozzle flow coupled with spray for a diesel injector using an Eulerian spray atomization model. Abstract The injector dynamics have a strong impact on spray behavior, therefore on combustion efficiency and pollutant emissions. Nozzle flow and spray coupled simulations are useful tools to analyze the effect of nozzle geometry, and they could be used also to study the effect of needle movement. In this work, three different approximations to the same needle lift law are employed in an Eulerian Spray Atomization (ESA) model. The main advantage of this model is that is able to simulate nozzle flow and spray seamlessly. Engine Combustion Network (ECN) Spray A conditions are simulated. Results show that the experimental needle lift law can be used without any fitting to a smoothed expression, but all details of the needle dynamics must be considered in order to properly predict mass flow rate and spray penetration. Additionally, it has been shown that needle dynamics has a strong impact on heating effects inside the nozzle.Keywords Multi-phase · CFD · needle dynamics · atomization · fuel injection · moving mesh Final author version, cite as: Payri, R., Gimeno, J., Mart-Aldarav, P. et al. "Numerical simulation of needle movement nozzle flow coupled with spray for a diesel injector using an Eulerian spray atomization model", J Braz.