RADIATIVE IGNITION AND COMBUSTION ENHANCEMENT FOR NAVY AIRCRAFT PROPULSION SYSTEMS

SUCCESSFUL OPERATION OF FUTURE NAVY AIRCRAFT PROPULSION SYSTEMS DEPENDS ON THE ATTAINMENT OF SIGNIFICANT ADVANCES IN COMBUSTION TECHNOLOGY. THE CONDITION OF HIGH FLIGHT-SPEED IMPOSES SEVERE STRAINS ON IGNITION RELIABILITY, FLAMEHOLDING, AND OVERALL COMBUSTION EFFICIENCY.A NOVEL RADIATIVE TECHNIQUE TO ALLEVIATE THESE PROBLEMS IS PROPOSED. THE IDEA IS TO SELECTIVELY IRRADIATE COMBUSTION SPECIES. THE ENSUING PHOTO DISSOCIATIVE REACTIONS GENERATE HIGHLY REACTIVE RADICALS WHICH MODIFY THE GAS PHASE KINETICS AND LEAD TO IGNITION AND ENHANCEMENT VIA CHAIN-BRANCHING PATHS. THE OVERALL OBJECTIVE OF PHASE IS TO EXPERIMENTALLY DETERMINE THE FEASIBILITY OF USING THE RADIATIVE TECHNIQUE TO OBTAIN RELIABLE IGNITION OF JET FUELS UNDER FLOW CONDITIONS. SPECIFIC TASKS IN THIS EFFORT INCLUDE INVESTIGATING MINIMUM IGNITION ENERGY, POWER REQUIREMENTS, FLOW CONDITIONS, RADIANT FREQUENCY (UV TO IR), AND RELIABILITY. IF TIME PERMITS, THE EFFECT OF THIS TECHNIQUE ON IGNITION DELAY TIME AND FLAMEHOLDING WILL BE ALSO STUDIED. ANTICIPATED BENEFITS FOR NAVAL AIRCRAFT PROPULSION SYSTEMS ARE RELIABLE RADIATIVE IGNITION AND FLAMEHOLDING. THESE OPTICAL AND NONINTRUSIVE MEANS CAN ELIMINATE ENGINE-DEGRADING PRESSURE LOSSES PRODUCED BY CONVENTIONAL DEVICES, AND CAN OFFER A SIGNIFICANT REDUCTION IN IGNITION DELAY TIME RESULTING IN IMPROVED OVERALL COMBUSTION EFFICIENCY AND SHORTER COMBUSTOR SIZE.