Numerical Study and Validation of the Near-Nozzle Spray Behavior of a Non-Proprietary Pressure-Swirl Atomizer for Aviation Applications

Examination and validation of internal fuel flow and spray morphology simulations in jet engines is crucial to improving the fidelity of predictive modeling of the relevant spray physics. Additionally, reliable modeling techniques are essential for enabling the adoption of sustainable, non-petroleum-based fuels in the aviation industry as a means of reducing emissions. In this study, we take advantage of the availability of the complete internal geometry of a non-proprietary atomizer, focusing on the pressure-swirl circuit, to provide reliable and accurate boundary conditions to characterize the near-nozzle fuel spray dynamics. We analyze the liquid injection through large-eddy simulations, modeling the two-phase flow using the VOF method. The simulations are performed using Jet A as the fuel of interest, and the fuel injection pressure is systematically varied to observe the impact of operating conditions on the near-nozzle spray structure. The morphology is analyzed to extract quantifications for cone angle, breakup length, and film thickness, and validated against X-ray phase contrast measurements. The reported results highlight the performance of the modeling methods for this non-proprietary atomizer operating a conventional petroleum-based fuel and define the basis to explore the performance of alternative fuels and their effect on the spray formation.