LASER IGNITION

Abstract :

Laser ignition has become an active research topic in recent years because it has the potential to replace the conventional electric spark plugs in engines. Compared to conventional spark ignition laser ignition allows more flexible choice of the ignition location inside the combustion chamber with the possibility to ignite even inside the fuel spray. Modern engines are required to operate under much higher compression ratios, faster compression rates, and much leaner fuel-to-air ratios than gas engines today. It is anticipated that the igniter in these engines will face with pressures as high as 50MPa and temperatures as high as 4000 K. Using the conventional ignition system, the required voltage and energy must be greatly increased (voltages in excess of 40 kV) to reliably ignite the air and fuel mixture under these conditions. Increasing the voltage and energy does not always improve ignitability but it does create greater reliability problem. Experiments with the direct injection engine have been carried out at the fundamental wavelength of the Nd:YAG laser as well as with a frequency doubled system Experiments show that above a certain threshold intensity of the laser beam at the window even highly polluted surfaces could be cleaned with the first laser pulse which is important for operation in real world engines.


laser ignition ppt


laser ignition report