It is important to understand the fluid dynamics inside the diesel injector and flow development in the nozzle due to their direct impact on the fuel-air mixing and combustion. This work uses a Eulerian approach and performs fully coupled simulations of the injector flow and near-field spray. This approach treats the liquid fuel and gas phases as a single mixture in the nozzle and near nozzle dense sprays. The liquid fuel mass fraction is transported with a model for the turbulent liquid diffusion flux using a Volume- of-Fluid method. The cavitation is modeled by the homogeneous relaxation model. A standard kepsilon turbulence model is used with round-jet correction. The well-characterized ECN spray B injector is simulated under the x-ray radiography measurement conditions. The transient flow development and cavitation phenomena are analyzed in details. The effect of the needle motion on the flow and hole-tohole variations is discussed. A comparison between the multi-hole injector and single-hole Spray A injector is also conducted.
CFD Modeling of the Nozzle Flow and Near-field Spray on ECN Spray B Injector
BATTISTONI, MICHELE;
2015
Abstract
It is important to understand the fluid dynamics inside the diesel injector and flow development in the nozzle due to their direct impact on the fuel-air mixing and combustion. This work uses a Eulerian approach and performs fully coupled simulations of the injector flow and near-field spray. This approach treats the liquid fuel and gas phases as a single mixture in the nozzle and near nozzle dense sprays. The liquid fuel mass fraction is transported with a model for the turbulent liquid diffusion flux using a Volume- of-Fluid method. The cavitation is modeled by the homogeneous relaxation model. A standard kepsilon turbulence model is used with round-jet correction. The well-characterized ECN spray B injector is simulated under the x-ray radiography measurement conditions. The transient flow development and cavitation phenomena are analyzed in details. The effect of the needle motion on the flow and hole-tohole variations is discussed. A comparison between the multi-hole injector and single-hole Spray A injector is also conducted.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
