Working in consort with
Ford Motor Company and Spectron Laser Systems, a research team at the University of Liverpool is developing a new and far more efficient Laser Ignition (LI) system that it says could one day replace the conventional spark plug in gasoline direct-injection engines. Using focused optical energy in place of its traditional counterpart would circumvent issues that spark plugs have in dealing with today's stratified-charge combustion environments and permit engines to operate on far leaner air-fuel mixes, netting better economy and considerably lower emissions. Dr. Tom Shenton, who heads up the UoL's Powertrain Laboratory, contends that reductions of 50 percent or more in hydrocarbons, carbon monoxide and oxides of nitrogen are possible by switching over to an LI system. After assessing several approaches to making LI function properly in an automotive application, the team chose a non-resonant breakdown format using a laser that produces energy in the near-infrared spectrum, which most closely approximates the functioning of an electric-spark ignition. Using a system of optical fibers, splitters and mirrors to deliver the LI energy from a single laser to each of the test engine's four cylinders, the team was able to optimize combustion stability and enhance operating efficiencies throughout a full spectrum of load conditions. Although formidable challenges still remain in taking the system from prototype to production, the group has moved on to a follow-up stage in the development process, filing protective patents and further fine tuning the process as they prepare it to move from the laboratory to the streets.