There is a recognition that fuel atomization and the fuel/air mixing near the fuel injector both have a significant effect on non-volatile particulate matter emission (nvPM) formation. These factors are especially important for Rich-Quench-Lean combustion technologies used in many smaller, modern combustors, where nitrogen oxides (NOx) and nvPM trade-offs must be managed through improved mixedness. The goal of this project is to investigate how jet fuel atomization affects the formation and oxidation of nvPM in engine-relevant conditions (pressure, temperature, flow) and develop a validated numerical model for the design of novel fuel injector to reduce nvPM formation in aero-engines. To achieve this goal, the research team will measure the velocity field, and fuel droplet size and spatial distribution inside the combustor to understand the fuel/air mixing process, intermediate combustion product distributions, nvPM volume fraction and size distribution, and exhaust gas composition to understand the kinetic formation and oxidation process of nvPM. The proposed comprehensive diagnostics will be conducted for a set of current (for baselining) and proposed new fuel injectors provided by an industry partner. The comprehensive experimental data will be used to validate computational models for both a baseline and novel fuel injector to reduce nvPM formation.
The intended purpose of this project is to provide breakthrough reductions in nvPM emissions through novel design of the injector at relevant conditions. This project will do this by enabling the development of fuel injectors that have improved fuel atomization and reduced nvPM formation. The aviation industry lacks data on the relationship between nvPM mass and number with fuel atomization, especially in relevant geometries and conditions, which this project is aimed to improve. The project would provide a vital experimental dataset to not only demonstrate reductions in nvPM from a given set of injectors but also to provide important data for numerical models to further calibrate nvPM predictions and thereby lead to further insights and aero engine performance improvements.