Multiple Laser Pulse Ignition for Ultra Cold Starting of CI Engines

The demonstration of CI engine injector ignition using multiple laser energy pulsing at cold soak conditions approaching -40F is proposed. This level of ignition performance will be demonstrated using a 150 mj Nd:YAG laser, low cost fiber optics, and quartz windows to minimize cost and packaging. Specific Phase I research includes: 1) Experimental quantification of optimally pulsed laser energy, Q-switching specifications, beam quality, and focal point flexibility using a Caterpillar CI engine injector test configuration at ambient and cold soak (<0 deg F) conditions. 2) CCD camera photography (250 nanosecond frame speeds) of numerous laser (Nd:YAG and Cr:LiSAF) ignition and flame propagation events in the Phase I test rig. 3) Analytical characterization of laser ignition and flame propagation using transient Computational Fluid Dynamics and specialized laser beam propagation theory. 4) Specification and layout of all system components (fuel injection, electronics, optics, windows, etc.) to demonstrate minimal system complexity and low cost. As a result of this rigorous scientific comparison between numerical simulation and CCD camera photography, Phase I is expected to generate revolutionary insights into cold fuel ignition from CI engine injectors. Phase II will focus on refining, packaging, and testing the technology defined in Phase I within a Caterpillar production engine setting. Phase III will include transferring and marketing the developed laser ignition and flame propagation techniques to the entire U.S. reciprocating and gas turbine community. BENEFITS: The ability to precisely deliver optimally pulsed laser energy for ultra cold CI engine starting will generate numerous cmmercial and military technological breakthroughs. These include robust reciprocating engine cold starting, instantaneous flame stabilization during abrupt aircraft maneuvers and dramatically enhanced lean premixed solid, liquid or gaseous combustion operation for ultra-low emissions. CFDRC's existing working relationships with U.S. reciprocating and gas turbine engine manufacturers assures rapid commercialization of the laser controlled/augmented combustion technology developed here.