Imaging studies of in-cylinder HCCI combustion

Abstract

An optically accessed, single cylinder engine operated in homogenous charge compression ignition (HCCI) mode with negative valve overlap (NVO) strategy was used to perform combustion processes diagnostics under premixed conditions corresponding to the low load regime of the HCCI operational envelope. The aforementioned processes analysis was conducted utilizing synchronized simultaneous combustion event crank-angle resolved images, acquired through piston crown window with in-cylinder pressure recording. This investigation was carried out for one-step ignition fuel—standard gasoline, fuel proceeding single-stage ignition process under conditions studied. The initial combustion stage is characterized by a maximum local reaction spreading velocity in the range of 40–55 m/s. The later combustion stage reveals values as high as 140 m/s in case of stoichiometric combustion. The mixture as well as combustion stages effects are pronounced in these observed analytical results.

Keywords

high speed imaging / combustion / homogenous charge compression ignition (HCCI) / reaction spreading velocity

References

[1] Zhao F, Asmus T W, Assanis D N, Dec J E, Eng J A, Najt P M. Homogenous Charge Compression Ignition (HCCI) Engines: Key Research and Development Issues. Warrendale, PA, USA: Society of Automotive Engineers. 2003, 3–4, 325–342

[2] Heywood J B. Internal Combustion Engine Fundamentals. Singapore: McGraw-Hill Book Co, 1998, 106, 497–500

[3] Wilson T, Xu H M, Richardson S, Wyszynski M L, Megaritis TM L. Optical study of flow and combustion in an HCCI engine with negative valve overlap. Journal of Physics: Conference Series, 2006, 45: 94–103

[4] Aleiferis P G, Charalambides A G, Hardalupas Y, Taylor A M K P, Urata Y. Autoignition initiation and development of n-heptane HCCI combustion assisted by inlet air heating, internal EGR or spark discharge: An optical investigation. SAE Paper, 2006, 2006–<month>01</month>–<day>3273</day>

[5] Persson H, Hultqvist A, Johansson B, Remon A.Investigation of the early flame development in spark assisted HCCI combustion using high speed chemiluminescence imaging. SAE Paper, 2007, 2007–<month>01</month>–<day>0212</day>

[6] Hwang W, Dec J E, Sjoberg M. Spectroscopic and chemical-kinetic analysis of the phases of HCCI autoignition and combustion for single- and two-stage ignition fuels. Combustion and Flame, 2008, 154(3): 387–409

[7] Hultqvist A, Christensen M, Johansson B, Richter M, Nygren J, Hult J, Alden M. The HCCI combustion process in a single cycle – Speed fuel tracer LIF and chemiluminescence imaging. SAE Paper, 2002, 2002–<month>01</month>–<day>0424</day>

[8] Dobosz M. Statistical Analysis of an Experimental Results. Warsaw: EXIT Publishing House, 2004, 1–50

[9] Wrobel Z, Koprowski R. Image Processing Methods Using Matlab. Warsaw: EXIT Publishing House, 2004, 96

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Higher Education Press and Springer-Verlag Berlin Heidelberg