A multi-institutional research team led by Washington University in St. Louis has received a five-year, $4.25 million grant from the Defense Advanced Research Projects Agency to develop improved fuel injector designs for advanced aircraft and defense applications.
The project is led by James Friend, the Stephen F. & Camilla T. Brauer Distinguished Professor of mechanical engineering and materials science at Washington University’s McKelvey School of Engineering.
Friend will work with collaborators from the University of California, San Diego, the University of Central Florida and the University of Florida.
The researchers plan to combine artificial intelligence with physics-based simulations to better understand atomization, the process through which liquid fuel breaks into droplets.
Atomization has remained a difficult engineering problem because liquid breakup involves several interacting physical principles that are challenging to represent with simple equations.
Understanding and controlling droplet formation matters for advanced propulsion systems because droplet size and behavior affect how efficiently fuel mixes with air and burns.
The challenge grows more significant for high-speed and hypersonic flight, where engine operating environments complicate fuel injector design.
The project is part of DARPA’s Automated Discovery for Design and Control of Turbulent Systems, or AutoDIDACTS, program.
AutoDIDACTS is seeking to demonstrate and validate new data-informed methods for exploring and optimizing aeronautics designs and turbulent-control problems relevant to the Department of War.
The WashU-led team will use a small-scale laboratory platform to study droplet breakup and test thin-film atomizers.
Researchers will also test thicker-film atomizers under airflow and validate their findings using a detonation tube.
AI tools will then be used to identify patterns within the experimental results.
Those patterns are expected to help researchers develop design maps that engineers can use when creating future fuel injectors.
The goal is to shift fuel injector development away from trial and error and toward more predictable engineering principles.
The resulting research could help engineers design fuel injectors faster while improving combustion stability and supporting technologies, including detonation-based and hypersonic propulsion.
The DARPA-funded project builds on another effort underway in Friend’s laboratory called PLIANT, which is developing an ultrasound atomization nozzle.
PLIANT aims to create a system that produces droplets smaller than 10 micrometers.
Droplets at that scale could evaporate more rapidly, mix more effectively with air and improve engine efficiency.
KEY QUOTES:
“Droplet formation affects how well fuel mixes and burns. This is especially important for high-speed and hypersonic flight, where engines are much harder to design. Our goal is to find simple design rules that engineers can use.”
“These results will help engineers to design fuel injectors faster as well as improve combustion stability and support detonation-based and hypersonic propulsion. We want to turn fuel-injector design from a lot of trial and error into a more scientific, reliable process.”
James Friend, Stephen F. & Camilla T. Brauer Distinguished Professor of Mechanical Engineering and Materials Science at Washington University in St. Louis
