Lasers set to stun engines into efficiency

摘要

Pew pew! For a week last November an internal combustion engine hummed away in a lab near Chicago. Why the excitement? This particular engine sets fire to fuel with lasers instead of spark plugs, burning fuel more efficiently than normal. Laser-fired engines could lead to cleaner, greener cars. In a normal combustion engine, a mix of fuel and air enters a chamber where it is ignited by a spark plug. Hot, expanding gases from the burning fuel then exert force on a moving part such as a piston - generating mechanical energy that can be used to turn the wheels of a car, for example. But because each combustion cycle happens very quickly, it is hard to get all of the fuel mixture to burn. The problem is that spark plugs can only ignite the fuel at one end of the chamber, says Chuni Ghosh, CEO of New Jersey-based Princeton Optronics, the firm that developed the new ignition system.