Laser Ignition for Large Scale Combustion Air Heaters

ABSTRACT: A Comprehensive assessment and rigorous documentation of a customized fiber optic coupled laser system as the ignition system within the Aerodynamic and Propulsion Test Unit (APTU) Combustion Air Heater (CAH) at AEDC is proposed. CFDRC will leverage prior successful gas turbine, rocket and cannon laser ignition implementation efforts and expertise to optimize laser energy and multiplexing requirements, Q-switching specifications, beam quality and focal point locations(s) for robust laser based ignition of the AEDC APTU CAH. Phase I effort will include: 1. Analytical comparison between the existing and our laser ignition process within the APTU CAH using conventional and high fidelity numerical analysis; 2. Rigorous description and specification of the required commercial laser hardware and customized software to be employed in developing and demonstrating a working system; 3. Conceptual design of an integrated system within with the APTU CAH combustion chamber and swirler cup assembly in the place of the existing hydrogen / air torches; and 4. Assessment of the system in a combustion diagnostics mode. The proposed evaluation of the ignition event, flame propagation and stabilization process within the APTU CAH will be critical to definition of an improved and increased safety based process for bringing the APTU CAH on line during routine wind tunnel testing events. Phase II will focus on building and demonstrating an operational prototype laser ignition system using flowing air as the oxidizer and atomized liquid isobutane as the fuel at pressures ranges from ambient to 50 psia. BENEFIT: This laser ignition system will be customized for implementation within the"slave"combustion process and be immediately suitable for implementation within numerous boiler applications. The proposed laser and optics technologies could provide the breakthroughs necessary to revolutionize combustion chamber ignition in numerous military and commercial internal combustion and gas turbine engine applications. CFDRC"s working relationships with numerous government labs, commercial laser equipment manufacturers and most engine and boiler equipment manufacturers assures rapid Phase III commercialization.