Buji ateşlemeli motorlarda yağ filmi tarafından taşınan HC emisyonlarının modellenmesi

Silindir gömleği üzerindeki yağ filmi motor çıkış HC emisyonlarının ana kaynaklarından biri olarak bilinmektedir. Bu çalışmada, yağ filmi içine yakıtın emilme/salınma oranı için bir matematik model geliştirilmiştir. İlk olarak, silindir gazlarının termodinamik özellikleri (basınç, sıcaklık ve Henry sabiti -H-)bir çevrim boyunca hesaplanmıştır. Daha sonra, Henry ve difüzyon kanunlarını kullanarak, yakıtın yağ filmi içine kütlesel emilme/salınma hızının etkisi, motor devrine, yağ filmi kalınlığına ve difüzyon katsayısına göre incelenmiştir.

Oil film on cylinder liner has been suggested as a major source of engine-out hydrocarbon emissions. In this study, a mathematical modelling for the rate of absorption/desorption of the fuel in the oil film has been developed. First of all, the thermodynamic properties of the cylinder gases (pressure, temperature and Henry constant -H-) have been calculated through a cycle. Then, using Henry and diffusion laws, the effect of the rate of absorption/desorption of the fuel in the oil film has been investigated depending on engine speed, oil film thickness and diffusion coefficient.

PDF

___

[1] ADAMCZYK, A.A., ROTHSCHILD, W.G. and KAISER, E.W. 1985. The Effect of Fuel and Oil Structure on Hydrocarbon Emissions from Oil Layers During Closed Vessel Combustion. Combustion Science and Technology, 44:113-124

[2] CHENG, W.K., HAMRIN, D. and HEYWOOD, J.B. 1993. An Overwiev of Hydrocarbon Emissions Mechanisms in Spark-Ignition Engines. SAE Paper No: 932708.

[3] ÇENGEL, A.Y. and BOLES, M.A. 1990. Thermodynamics An Engineering Approach. McGraw-Hill International Editions.

[4] DERIOVE, J. and CHENG, W.K. 1995. Simultaneous Piston Ring Friction and Oil Film Thickness Measurements in a Reciprocating Test Ring. SAE Paper No: 952470.

[5] HAMRIN, D.A. 1994. Modeling of Engine-Out HC Emissions for Prototype Production. Master thesis. Massachusetts Institute of Technology.

[6] HAMRIN, D.A. and HEYWOOD, J.B. 1995. Modeling of Engine-Out Hydrocarbon Emissions for Prototype Production Engines. SAE Paper No: 950984.

[7] HEYWOOD, J.B. and HOCHGREB, S. 1996. Measurement of Gasoline Absoption into Engine Lubricating Oil. SAE Paper No: 961229.

[8] HEYWOOD, J.B. 1989. Internal Combustion Engine Fundementals. McGraw-Hill International Editions. Singapore,930 s.

[9] KARAMANGİL, M. İ. 2000. Benzin Motorlarında HC Emisyonlarının Matematik Modellenmesi. Doktora tezi. U.Ü. Fen Bilimleri Ens. 30 Mart 2000. Bursa.

[10] KOREMATSU, K. 1990. Effect of Fuel Absorbed in Oil Film on Unburnt Hydrocarbon Emissions from Spark Ignition Engines. JSME International Journal Series II, 33 (3):

[11] LAVOIE, G.A. and BLUMBERG, P.N. 1980. A Fundemental Model for Predicting Fuel Consumption, Nox and HC Emissions of The Conventional Spark Ignited Engine. Combustion Science and Technology, 21: 225-258

[12] MIN, K. and CHENG, W.K. 1998. Oil Layer as Source of Hydrocarbon Emissions in SI Engines. Journal of Engineering for Gas Turbines and Power- Transactions of the ASME. 120 (3): 669-677.

[13] MIN, K. CHENG, W.K. and HEYWOOD, J.B. 1994. The Effects of Crevices on the Engine-Out Hydrocarbon Emissions in SI Engines. SAE Paper No: 940306.

[14] MIN, K. and CHENG, W.K. 1994. In-Cylender Oxidation of Piston-Crevice Hydrocarbon in SI Engines. The Third International Symposium on Diagnostics and Modeling of Combustionin in Internal Combustion Engines. Yokohama-Japan: 125-130

[15] NORRIS, M.G. and HOCHGREB, S. 1996. Extent of Oxidation of Hydrocarbons Desorbing from the Lubricant Oil Layer in Spark-Ignition Engines. SAE Paper No: 960069.

[16] SCHRAMM, J. and SORENSON, S.C. 1990. A Model for Hydrocarbon Emissions From SI Engines. SAE Paper No: 902169.

[17] WILLCOCK, M., TIDMARSH, D. FOSS, P.1996. The Variation of Hydrocarbon Emissions from Different Piston Designs in a Spark Ignition Engine. Journal of Automobile Engineering, 210 (3): 235-242.