Design of a plasma-assisted injector: Principle, characterization and application to supersonic combustion of hydrogen

A new design of plasma-assisted injector to ignite or stabilize combustion is presented. This design is intended to produce discharges that penetrate the combustion chamber instead of staying at the wall. This plasma-assisted injector, simple and robust, allows compact designs for a weakly intrusive implementation in engines, and is compatible with either air or fuel, depending on the process or application. A prototype was manufactured, implemented and tested with quasi-DC discharges on the LAPCAT2 Dual Mode Ramjet combustor at LAERTE facility in ONERA. Combustion tests showed earlier ignition and increased pressure when the plasma was turned on with a measured plasma power of 1.4 kW. •Presentation of the design and principle of a new plasma assisted injector.•Demonstration of its ability to generate discharges penetrating the flow.•Characterization of the discharge dynamics and its interaction with the gas flow.•Comparison of the discharge behavior in hydrogen vs air.•Ability of the plasma assistance to enhance supersonic combustion.