Laser Ignition in a Pre-Mixed Engine: The Effect of Focal Volume and Energy Density on Stability and the Lean Operating Limit Southwest Research Institute

Format:

Conference/Event

Author/Creator:

Alger, Terry, author.

Conference Name:

Powertrain & Fluid Systems Conference & Exhibition (2005-10-24 : San Antonio, Texas, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2005

Summary:

A series of tests using an open beam laser ignition system in an engine run on pre-mixed, gaseous fuels were performed. The ignition system for the engine was a 1064 nm Nd:YAG laser. A single cylinder research engine was run on pre-mixed iso-butane and propane to determine the lean limit of the engine using laser ignition. In addition, the effect of varying the energy density of the ignition kernel was investigated by changing the focal volume and by varying laser energy. The results indicate that for a fixed focal volume, there is a threshold beyond which increasing the energy density [kJ/m3] yields little or no benefit. In contrast, increasing the energy density by reducing the focal volume size decreases lean performance once the focal volume is reduced past a certain point. The effect of ignition location relative to different surfaces in the engine was also investigated. The results show a slight bias in favor of igniting closer to a surface with low thermal conductivity. Overall, the results show that a laser ignition system is capable of igniting mixtures with equivalence ratios much lower than typical in an engine - as low as =0.45 for propane while maintaining acceptable combustion stability (CoV imep < 5%)

Notes:

Vendor supplied data

Publisher Number:

2005-01-3752

Access Restriction:

Restricted for use by site license