Spectroscopic Measurements in Small Two-Stroke SI Engines 2009-32-0030
This paper demonstrates the potential of optical sensors in the combustion chamber of a small two-stroke SI engine to detect conditions that hinder an optimal combustion process using emission bands and/or emission lines. The primary focus is on the spectroscopic examination of the combustion radiation emissions cycle-by-cycle. For this purpose, spark-ignition type combustion events, as well as the influence of both the air-fuel-ratio and the fuel type, are investigated on a crank angle resolved basis.
Furthermore, an assessment of the radiation emissions of the OH, CH and C2 radicals is made. As a next step, the calculation of a temperature profile inside the combustion chamber is attempted by means of the line-emission-method regarding the thermally excited alkaline metals sodium and potassium. These data enable recognition of diffusion combustion and the detection of inadequate mixture quality.
Kai W. Beck, Thomas Heidenreich, Steve Busch, Ulrich Spicher, Tim Gegg, Armin Kölmel
Universität Karlsruhe (TH), Germany, Andreas STIHL AG & Co. KG, Waiblingen, Germany
Small Engine Technology Conference & Exposition