Low energy laser-induced ignition of an air-fuel mixture

Abstract

A new approach for igniting an air-fuel mixture in a turbine or other engine is disclosed. Resonance-enhanced multiphoton ionization (REMPI) is used to generate volume ionization within an air-fuel flow and induce an ignition arc. The output of a relatively low energy single pulsed ultraviolet laser is aimed across an electric field inside a volume of air to create a pre-ionized channel so that a smaller voltage electric field is sufficient to create an electrical arc that follows the pre-ionized channel and will ignite an air-fuel mixture. Because the arc follows the pre-ionized channel, it can be directed to an optimal location inside an ignition volume for igniting the air-fuel mixture. A specific example embodiment is described using a 287.5 nm wavelength pulsed ultraviolet laser to excite ground state oxygen molecules to a specific excited state having a coincident term energy with a specific nitrogen molecule excited state.

Dependencies are inferred from the claim text.