Multi Pulse laser Ignition for Ultra Cold Turboshaft Engine Starting

Recent CFDRC and Los Alamos National Lab CRADA research activity has demonstrated 100% JTAGG fuel injector ignition reliability at fuel tesperatures approaching -10 F using precisely controlled multiple pulse formatting of a single 150 mj laser discharge. This level of performance is achievable with minimal packaging complexity using diode pumped Nd:YAG lasers and demonstrated fiber optics/windows technologies. Conclusive Phase I demonstration will include: 1. Experimental quantification of laser ignition energy, pulse formatting, Q-switching specifications, beam quality, and focal point flexibility at ambient and cold soak (<-10 deg F) JTAGG fuel injection conditions. 2. CCD camera photography (250 nanosecond frame speeds) of numerous laser ignition events. 3. Analytical laser ignition characterization of cold fuel sprays using transient conputational Fluid Dynamics and specialized laser beam propagation theory. 4. Specification and layout of all system components (fuel injection, electronics, optics, windows, etc.) to demonstrate comparable complexity and cost with capacitive discharge technology in an AlliedSignal JTAGGs combustion system. 5. Assessment of laser apparatus in a diagnostics mode. Phase I is expected to generate revolutionary ignition insights as a result of comparison between numerical simulation and CCD camera photography. Phase II will focus on refining and packaging the technology in a flight worthy setting and full scale evaluation in an AlliedSignal combustion test rig. Phase III will include marketing and transferring the developed laser ignition and cold engine acceleration flame stabilization techniques to the entire U.S. gas turbine and reciprocating engine community. BENEFITS: The ability to deliver precisely controlled laser energy for ignition, stabilization and flame monitoring will generate numerous conmercial and military technological breakthroughs. These include robust ignition in cold military environments, instantaneous flame stabilization during abrupt aircraft maneuvers and dramatically enhanced lean premixed solid, liquid or gaseous combustion operation for ultra-low emissions. CFDRc's mature working relationstips with all U.S. gas turbine and many r