Plasma Ignitor - Aero Ramp Injector for Ramjet/Scramjet Combustors

The US Air Force plans to develop and demonstrate an aero-propulsion engine for hypersonic flight to Mach 8. This program focuses on use of hydrocarbon fuels and expendable engine designs for long-range cruise missile applications. A critical element for realization to the Air Force's hypersonic vehile mission is advancement in supersonic combustion ramjet engine technology. Development of concepts to utilize hydrocarbon fuels that demonstrate reliable supersonic combustion and survivable hardware has a high priority. An opportunity exists to address combustion-related problems by integrating the performance features of a plasma arc ignitor with the injection dynamics of an "aero-ramp" injector.Phase I will demonstrate the operation of a plasma ignitor using hydrocarbon gases. Tests will be performed which will identify plasma ignitor-generated intermediates or radicals that may reduce autoignition temperatures and ignition delay times as well as enhance combusion efficiency. Performance and operational guidelines will be developed to optimize the integration of the plasma ignitor with an aero-ramp injector appropriate for testing in a full-scale, Phase II program. An integrated plasma ignitor/aero-ramp injection module will be designed based on scaling parameters relevant to full-scale, air-breathing propulsion and sized for future Phase II testing in a supersonic wind tunnel environment.