Optical Diagnostics of Laser-Induced and Spark Plug-Assisted HCCI Combustion 2005-01-0129
HCCI (Homogeneous Charge Compression Ignition), laser-assisted HCCI and spark plug-assisted HCCI combustion was studied experimentally in a modified single cylinder truck-size Scania D12 engine equipped with a quartz liner and quartz piston crown for optical access. The aim of this study was to find out how and to what extent the spark, generated to influence or even trigger the onset of ignition, influences the auto-ignition process or whether primarily normal compression-induced ignition remains prevailing. The beam of a Q-switched Nd:YAG laser (5 ns pulse duration, 25 mJ pulse energy) was focused into the centre of the cylinder to generate a plasma. For comparison, a conventional spark plug located centrally in the cylinder head was alternatively used to obtain sparks at a comparable location. No clear difference in the heat releases during combustion between the three different cases of ignition start could be seen for the fuel of 80/20 iso-octane/n-heptane used. However, with optical diagnostic methods, namely PLIF (Planar Laser-Induced Fluorescence), Schlieren photography and chemiluminescence imaging, differences in the combustion process could be evaluated.
M. Weinrotter, E. Wintner, K. Iskra, T. Neger, J. Olofsson, H. Seyfried, M. Aldén, M. Lackner, F. Winter, A. Vressner, A. Hultqvist, B. Johansson
Photonics Institute, Vienna University of Technology, Institute of Experimental Physics, Graz University of Technology, Division of Combustion Physics, Department of Physics, Lund Institute of Technology, Institute of Chemical Engineering, Vienna University of Technology, Division of Combustion Engines, Department of Heat and Power Engineering
SAE 2005 World Congress & Exhibition
Homogeneous Charge Compression Ignition (HCCI) Combustion on CD-ROM from the SAE 2005 World Congress-SP-1982CD, Homogeneous Charge Compression Ignition (HCCI) Combustion 2005-SP-1963, SAE 2005 Transactions Journal of Engines-V114-3