A new approach to compute temperature in a liquid-gas mixture. Application to study the effect of wall nozzle temperature on a Diesel injector

Thermal effects on internal combustion engines have been always a hot topic. Its effects also on the injection system are still under research. In this work, a homogeneous model called Eulerian Spray Atomization (ESA) model is used to simulate Engine Combustion Network (ECN) Spray A conditions. A new approach is used for the thermodynamic model in Diesel spray simulations. Experimental values of the liquid enthalpy are directly used to obtain the temperature, without any need of knowing its heat capacity. This allows to accurately study heating and cooling phenomena inside the Diesel nozzle. The results show that two different boundary conditions can be applied at nozzle walls, either fixed temperature or adiabatic walls, and 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, but fluid properties inside the nozzle (density, velocity...) significantly change.