Estimation of the shape factor (m) in Wiebe function at different operating conditions for a SI engine

Öz

The burning process is one of the most important periods, which affects thermal efficiency and exhaust gas emissions, in internal combustion engines. The combustion process in internal combustion engines is modeled with one-dimensional or multi-dimensional software because it is cheaper, faster, and more practical than experiment. One of these methods, which is used to model the combustion period, is the Wiebe function. The Wiebe equation is an approach used in calculating the mass fraction burned and the heat release rate. The selection of Wiebe parameters is one of the most important factors affecting the accuracy of the mass fraction burned. In this study, the measured cylinder pressure of a spark ignition engine was directly used to calculate the heat released rate. The experiments were conducted at different brake mean effective pressures, engine speeds and relative air/fuel ratios, which were called independent variables. The shape factor (m) was determined by fitting the Wiebe equation to the heat release rate curves, which were extracted from the experimental results. The relationship between determined shape factor and independent variables was analyzed with a statistical approach. Eventually, a linear regression model, which explains 80% of the change in the shape factor, was created.

Anahtar Kelimeler

• Mass fraction burned
• Combustion process
• Heat release rate
• Spark ignition engine
• Wiebe function.

Kaynakça

1. Heywood JB., “Internal Combustion Engine Fundamentals”, NewYork: McGraw-Hill Education; 1988. https://doi.org/10.5860/choice.26-0943.
2. Pulkrabek WW., “Engineering Fundamentals of the Internal Combustion Engines”, USA: Pearson Prentince Hall; 2004.
3. Demirci A., “The effects of different combustion chamber geometries on the performance and emissions of an internal combustion engine”, Istanbul Technical University, Ph.D. Thesis; 2017.
4. Doǧan HE, Kutlar OA, Javadzadehkalkhoran M, Demirci A., “Investigation of burn duration and NO emission in lean mixture with CNG and gasoline”, Energies, Volume:12 Issue: 4432. DOI: https://doi.org/10.3390/en12234432.
5. Pischinger F, Walzer P. Future trends in automotive engine technology. XXVI’th Congress FISITA, vol. 3, Prague: 1996.
6. Menacer B, Bouchetara M., “The automotive engine modeling for steady-state condition using FORTRAN/GT-POWER”, International Journal of Automotive Engineering and Technologies, Volume:4 Issue:3, pp:118–29. 2015.
7. Kutlar OA, Cihan Ö., “Investigation of Parameters Affecting Rotary Engine by Means of a One Zone Thermodynamic Model”, J Energy Resour Technol, Volume: 144, Issue:4, 042304. 2022. DOI: https://doi.org/10.1115/1.4052615.
8. Kutlar OA, Malkaz F., “Two-Stroke Wankel Type Rotary Engine: A New Approach for Higher Power Density” Energies, Volume:12, 4096, 2019. DOI: https://doi.org/10.3390/en12214096.

9. Giglio V, di Gaeta A., “Novel regression models for Wiebe parameters aimed at 0D combustion simulation in spark ignition engines”, Energy, Volume: 210, 118442, 2020. DOI: https://doi.org/10.1016/j.energy.2020.118442.
10. Hu D, Wang H, Wang B, Shi M, Duan B, Wang Y, et al., “Calibration of 0-D combustion model applied to dual-fuel engine”, Energy, Volume: 261 Issue: Part B, 125251, 2022. DOI: https://doi.org/10.1016/J.ENERGY.2022.125251.
11. Yeliana Y, Cooney C, Worm J, Michalek DJ, Naber JD., “Estimation of double-Wiebe function parameters using least square method for burn durations of ethanol-gasoline blends in spark ignition engine over variable compression ratios and EGR levels”, Appl Therm Eng, Volume: 31, Issues: 14-15, 2011. DOI: https://doi.org/10.1016/j.applthermaleng.2011.01.040.
12. Arslan H, Kutlar OA, Mehdiyev R., “Development of a combustion chamber for optimum combustion process in diesel engines”, Uluslararası Yakıtlar Yanma Ve Yangın Dergisi, Volume:1, pp. 50–58, 2019.
13. Yontar AA., “Effects of ethanol, methyl tert-butyl ether and gasoline-hydrogen blend on performance parameters and HC emission at Wankel engine”, Biofuels, Volume: 11, Issue: 3, pp: 377-388, 2020. DOI: https://doi.org/10.1080/17597269.2019.1613765.
14. Yontar AA., “Numerical Comparative Mapping Study to Evaluate Performance of a Dual Sequential Spark Ignition Engine Fuelled with Ethanol and E85”, International Journal of Automotive Engineering and Technologies, Volume: Issue:3, pp. 98–106, 2018. DOI: https://doi.org/10.18245/ijaet.486405.
15. Kutlar OA., “A New method to decrease the fuel comsumption at part load conditions of four stroke ottocycle (rochas) engine (skipperiod engine)”, Istanbul Technical University, Ph. D. Thesis, 1999.
16. Tekeli Ö., “Designing and Production Ignition and Injection Units of a Gasoline Engine with Skip Cycle”, İstanbul Technical University, Master Thesis 2013.
17. Güler F., “Istatistik Methods and Applications”, Türkiye, Beta Basım Yayım, 2012. Montgomery DC., “Design and analysis of experiments”, 8th ed. John wiley & sons, 2017.