Electrostatic atomizing fuel injector for small scale engines

The goal of this proposal is to develop a fuel injection system for direct-injection, spark-ignition, small engines that provides tunable atomization and good fuel-air mixture with low power consumption, low weight penalty, and small space footprint. The proposed method injects electric charge into an electrically insulating liquid, such as JP-8, within a specific atomizer design. The primary atomization of the jet emerging from the atomizer is enhanced by the presence of the electric charge as is the downstream dispersion of the spray. The essence of the ‘charge injection’ concept is that the high-voltage electrode supplying the electric current is encased within an earthed atomizer and completely immersed within the liquid fuel being sprayed. This ensures that the high voltage electrode is completely decoupled from the ionized combustion environment and cannot ‘short’ through it. The proposed research will use in-house, specialized CFD codes to identify the drop size and charge requirements for particular time and length scales involved in small engines burning JP-8. Our preliminary estimates indicate that, while we know our existing single-orifice atomizer will successfully spray JP-8, a novel multi-orifice design will be more suited to meet the above requirements. The proposed effort will benefit from collaboration with the University of Illinois at Chicago with extensive expertise in both internal combustion engines and development of electrostatic atomizers for combustion applications.