Adaptation of Gas Engines for Efficient Use of the Advantages of Laser Ignition

Laser ignition of combustion processes has drawn much attention due to the increased availability and reliability of miniaturised lasers. The ignition process starts with a nonresonant breakdown in the focus of a pulsed laser, the formation of a plasma and the expansion of hot gases and free radicals into the gas volume. The advantages of laser ignition is the free choice of ignition location and the absence of disturbing electrodes, allowing ignition of leaner mixtures and optimisation of the combustion process. Primary application goals are stationary gas engines or stabilising support ignition in alternative combustion concepts like HCCI (homogeneous Charge Compression Ignition) engines. Experimental investigations focused on laser development, plasma and flame diagnostics and investigation of alternative combustion processes. A broad spectrum of optical, spectroscopic and laser metrological methods were applied to investigate the development of laser plasma, perform laser spectroscopy on reaction intermediates or in-situ temperature measurements at high pressures. Current research focuses on the modification of engine layout with the goal to take advantage of the potentials of laser ignition, better reliability of laser and optical components and the development of cost efficient pump diode systems.