In cylinder expansion of ring crevice and oil film hydrocarbons in SI engines M.I. Karamangil a, * , A. Surmen a , M.Z. Gul b a Department of Mechanical Engineering, Faculty of Engineering and Architecture, Uluda g University, TR-16059 Bursa, Turkey b Department of Mechanical Engineering, Faculty of Engineering, Marmara University, Istanbul, Turkey Received 10 February 2003; received in revised form 1 December 2003; accepted 26 December 2003 Available online 6 March 2004 Abstract A computational approach has been presented for calculation of just-past-port hydrocarbons (HCs) releasedfromringcrevicesandoilfilm.Timedependentincylindergasconcentrationsarecalculatedbased onthesimplestcombustionreactionassumption,i.e.completetheoreticalcombustion(k ¼ 1),andacosine law for the combustion rate. Until the time the HC release starts, the fresh charge, or its mixture with combustion products, is assumed to be distributed homogeneously in the combustion chamber so that the governing equations need not be solved for this period. After that, the governing equations have been introduced for solution of the flow field except that the energy equation is replaced with a simple zero- dimensional phenomenological submodel at the expense of solution of the N–S equations. Post flame oxidation is not taken into account. Results are compared to the extent limited counterparts in the liter- ature allow, due to the lack of common parameters adopted in many of different studies. Ó 2004 Elsevier Ltd. All rights reserved. Keywords: Hydrocarbon emissions; Ring crevice; Oil film; Spark ignition engine Energy Conversion and Management 45 (2004) 3109–3126 www.elsevier.com/locate/enconman Abbreviations: ATDC, after top dead center; ABDC, after bottom dead center; BBDC, before bottom dead center; BTDC,beforetopdeadcenter;BDC,bottomdeadcenter;TDC,topdeadcenter;CA,crankangle;EVO,exhaustvalve opening; HCs, hydrocarbons; PDEs, partial differential equations; PISO, pressure implicit by splitting of operators. * Corresponding author. Tel.: +90-224-442-8176; fax: +90-224-442-8021. E-mail addresses: ihsan@uludag.edu.tr (M.I. Karamangil), surmen@uludag.edu.tr (A. Surmen), zgul@eng.mar- mara.edu.tr (M.Z. Gul). 0196-8904/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.enconman.2003.12.022