Abstract
Jet breakup with a conical nozzle was studied including in-nozzle flow based on a modified compressible two-fluid model coupled with the large eddy simulation model in the OpenFOAM framework. In order to capture the interface, the phase equation and the pressure equation were modified by adding the quasi-VOF model and surface tension respectively. The effects of temperature and pressure on the air thermal properties were taken into account and the density of diesel was fitted linearly with respect to the pressure according to experimental data. In addition, the Ranz-Marshall model was applied to consider the interphase heat transfer. The modified compressible two-fluid model was verified by comparing the calculated mass flow rates, discharge coefficients, spray momentum fluxes and effective jet velocities under different injection conditions with the available experimental results. It was demonstrated that the numerical simulation results agreed well with the experimental measurements with minor discrepancies which were caused by the numerical assumptions and the experimental uncertainty. Then the mechanism of jet breakup and the effects of the ambient temperature on jet breakup were investigated. It is found that jet breakup is divided into two regions, i.e. the intact region and the jet breakup region. The intact region is dominated by the spatial instability, and the jet breakup region is dominated by the combination of the temporal instability and the spatial instability. It's worth mentioning that the surface tension plays a dual role in inhibiting atomization of droplets and promoting the pinch-off of diesel column and ligament.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.