Center for Laser Applications

Laser-Induced Ignition 

Although laser ignition offers advantages for most combustion sources, its greatest potential exists for jet-engine gas-turbine combustors. The replacement of jet-engine spark-plugs with laser- ignitors provides the opportunity to use lighter-weight, lower- temperature materials and to achieve high-altitude relight after engine flameout. Following completion of the multi-year laser-ignition development contract with Allied Signal, basic research studies were continued by CLA in the investigation of laser-induced ignition of gas mixtures. Laser-visualization and spectroscopic techniques were used to observe specific features of the laser-induced combustion of ammonia- oxygen mixtures. Pulsed-laser shadowgraphs were obtained to see the spatial variations of the density of the combustion reactants and products. Typical shadowgraph results show laser-induced breakdown of these gas mixtures. The left-most figure shows the result for the breakdown of non-concentration ratio for an igniting ammonia- oxygen mixture, and the right-most image is the result for an igniting mixture of increased concentration of ammonia fuel. The differences in shape and size and, therefore, expansion speed are evident. The copper- vapor laser and fast electronic camera were used to observe a sequence of such images with temporal resolution of 10 nanoseconds at 75 microsecond-intervals. Two-dimensional images of the temperature profile of the NH free-radical were obtained using an excimer-pumped dye laser and planar laser-induced florescence (PLIF). Typical PLIF results show interesting vortex-like spatial structures.

Negotiations with the UTRC licensee Allied Signal have been on-going over the past year to allow UTRC and CLA to expand the application areas of this technology. Anticipating a favorable resolution of these discussions, CLA is discussing additional commercialization opportunities with both U.S. and foreign companies.

Investigators: Drs. J.W.L. Lewis and C. Parigger and J. Few 
Sponsor: CLA

These slide shows did not work on the old site.  If this is a page you want to keep, would you want these?  I don't know if I can fix this, but I can try.

  Introduction      Initial Plasma     Shadowgraphs

    Laser-Induced Fluorescence     Simulation