Estimation of the in-cylinder residual mass fraction at Intake Valve Closing in a 2-stroke High-Speed Direct-Injection Compression-Ignition engine

This is the author's version of a work that was accepted for publication in International Journal of Engine Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as https://doi.org/10.1177/1468087418813406.[EN] New combustion concepts and engine designs are being currently investigated in order to comply with upcoming pollutant regulations and reduce fuel consumption. In this context, two-stroke architectures appear as a promising solution for the implementation of some combustion concepts. However, scavenging processes in a two-stroke engine are much more challenging than for a four-stroke engine, and the residual mass of burnt gases retained inside the cylinder needs to be properly determined in order to keep control over the in-cylinder composition, hence over the combustion conditions and pollutant emissions. In this study, a new methodology for the estimation of the internal residual gas fraction is introduced, which is based on the thermodynamic processes occurring in the engine investigated and makes use of basic engine instrumentation and measurement equipment usually available in a conventional test cell. Several versions of the estimator were developed so that different requirements could be met, such as those of real-time estimation on an engine test bench but with reduced precision or, on the contrary, highly precise but time-consuming computations for post-processing purposes and combustion diagnosis. The consistency of the internal residual gas estimator was then validated through its application to real engine tests at different operating points.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research has been sponsored by the European Union in framework of the REWARD project, Horizon 2020 research and innovation program under grant agreement no. 636380. The authors kindly recognize the technical support provided by Mr Gilles Coma and his research group at RENAULT SAS, and also by the research group at IFPEN, along the development of the investigations presented here.Torregrosa, AJ.; Martín, J.; Novella Rosa, R.; Thein, K. (2020). Estimation of the in-cylinder residual mass fraction at Intake Valve Closing in a 2-stroke High-Speed Direct-Injection Compression-Ignition engine. International Journal of Engine Research. 21(5):838-855. https://doi.org/10.1177/1468087418813406S838855215Galindo, J., Luján, J. M., Serrano, J. R., & Hernández, L. (2005). Combustion simulation of turbocharger HSDI Diesel engines during transient operation using neural networks. Applied Thermal Engineering, 25(5-6), 877-898. doi:10.1016/j.applthermaleng.2004.08.004Payri, F., Benajes, J., Galindo, J., & Serrano, J. R. (2002). Modelling of turbocharged diesel engines in transient operation. Part 2: Wave action models for calculating the transient operation in a high speed direct injection engine. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 216(6), 479-493. doi:10.1243/09544070260137507Rakopoulos, C. ., Rakopoulos, D. ., Giakoumis, E. ., & Kyritsis, D. . (2004). Validation and sensitivity analysis of a two zone Diesel engine model for combustion and emissions prediction. Energy Conversion and Management, 45(9-10), 1471-1495. doi:10.1016/j.enconman.2003.09.012Gatowski JA, Balles EN, Chun KM, Nelson FE, Ekchian JA, Heywood JB. Heat release analysis of engine pressure data. SAE technical paper 841359, 1984.Lapuerta, M., Armas, O., & Hernández, J. J. (1999). Diagnosis of DI Diesel combustion from in-cylinder pressure signal by estimation of mean thermodynamic properties of the gas. Applied Thermal Engineering, 19(5), 513-529. doi:10.1016/s1359-4311(98)00075-1Arrègle, J., López, J. J., Garcı́a, J. M., & Fenollosa, C. (2003). Development of a zero-dimensional Diesel combustion model. Part 1: Analysis of the quasi-steady diffusion combustion phase. Applied Thermal Engineering, 23(11), 1301-1317. doi:10.1016/s1359-4311(03)00079-6Arrègle, J., López, J. J., Garcı́a, J. M., & Fenollosa, C. (2003). Development of a zero-dimensional Diesel combustion model. Applied Thermal Engineering, 23(11), 1319-1331. doi:10.1016/s1359-4311(03)00080-2Li J, Chae JO, Park SB, Paik HJ, Park JK, Jeong YS, et al. Effect of intake composition on combustion and emission characteristics of DI diesel engine at high intake pressure. SAE technical paper 970322, 1997.Brown WL. Methods for evaluating requirements and errors in cylinder pressure measurement. SAE technical paper 670008, 1968.Lancaster DR, Krieger RB, Lienesch JH. Measurement and analysis of engine pressure data. SAE technical paper 750026, 1975.Ghojel, J., & Honnery, D. (2005). Heat release model for the combustion of diesel oil emulsions in DI diesel engines. Applied Thermal Engineering, 25(14-15), 2072-2085. doi:10.1016/j.applthermaleng.2005.01.016Wu, Y., Wang, Y., Zhen, X., Guan, S., & Wang, J. (2014). Three-dimensional CFD (computational fluid dynamics) analysis of scavenging process in a two-stroke free-piston engine. Energy, 68, 167-173. doi:10.1016/j.energy.2014.02.107Yuan, C., Feng, H., He, Y., & Xu, J. (2016). Combustion characteristics analysis of a free-piston engine generator coupling with dynamic and scavenging. Energy, 102, 637-649. doi:10.1016/j.energy.2016.02.131Cheung HM, Heywood JB. Evaluation of a one-zone burn-rate analysis procedure using production SI engine pressure data. SAE technical paper 932749, 1993.Brunt, M. F. J., Rai, H., & Emtage, A. L. (1998). The Calculation of Heat Release Energy from Engine Cylinder Pressure Data. SAE Technical Paper Series. doi:10.4271/981052Payri, F., Molina, S., Martín, J., & Armas, O. (2006). Influence of measurement errors and estimated parameters on combustion diagnosis. Applied Thermal Engineering, 26(2-3), 226-236. doi:10.1016/j.applthermaleng.2005.05.006Broatch, A., Ruiz, S., Margot, X., & Gil, A. (2010). Methodology to estimate the threshold in-cylinder temperature for self-ignition of fuel during cold start of Diesel engines. Energy, 35(5), 2251-2260. doi:10.1016/j.energy.2010.02.012Olsen, D. B., Hutcherson, G. C., Willson, B. D., & Mitchell, C. E. (2002). Development of the Tracer Gas Method for Large Bore Natural Gas Engines—Part I: Method Validation. Journal of Engineering for Gas Turbines and Power, 124(3), 678-685. doi:10.1115/1.1454116Olsen, D. B., Hutcherson, G. C., Willson, B. D., & Mitchell, C. E. (2002). Development of the Tracer Gas Method for Large Bore Natural Gas Engines—Part II: Measurement of Scavenging Parameters. Journal of Engineering for Gas Turbines and Power, 124(3), 686-694. doi:10.1115/1.1454117Benajes, J., Olmeda, P., Martín, J., & Carreño, R. (2014). A new methodology for uncertainties characterization in combustion diagnosis and thermodynamic modelling. Applied Thermal Engineering, 71(1), 389-399. doi:10.1016/j.applthermaleng.2014.07.010Payri, F., Olmeda, P., Martín, J., & García, A. (2011). A complete 0D thermodynamic predictive model for direct injection diesel engines. Applied Energy, 88(12), 4632-4641. doi:10.1016/j.apenergy.2011.06.005Benajes, J., Novella, R., De Lima, D., Tribotté, P., Quechon, N., Obernesser, P., & Dugue, V. (2013). Analysis of the combustion process, pollutant emissions and efficiency of an innovative 2-stroke HSDI engine designed for automotive applications. Applied Thermal Engineering, 58(1-2), 181-193. doi:10.1016/j.applthermaleng.2013.03.050Benajes, J., Martín, J., Novella, R., & Thein, K. (2016). Understanding the performance of the multiple injection gasoline partially premixed combustion concept implemented in a 2-Stroke high speed direct injection compression ignition engine. Applied Energy, 161, 465-475. doi:10.1016/j.apenergy.2015.10.034Benajes, J., Novella, R., De Lima, D., & Thein, K. (2017). Impact of injection settings operating with the gasoline Partially Premixed Combustion concept in a 2-stroke HSDI compression ignition engine. Applied Energy, 193, 515-530. doi:10.1016/j.apenergy.2017.02.044Galindo, J., Serrano, J. R., Arnau, F. J., & Piqueras, P. (2009). Description of a Semi-Independent Time Discretization Methodology for a One-Dimensional Gas Dynamics Model. Journal of Engineering for Gas Turbines and Power, 131(3). doi:10.1115/1.2983015CARREÑO ARANGO, R. (s. f.). A comprehensive methodology to analyse the Global Energy Balance in Reciprocating Internal Combustion Engines. doi:10.4995/thesis/10251/73069Benajes, J., Olmeda, P., Martín, J., Blanco-Cavero, D., & Warey, A. (2017). Evaluation of swirl effect on the Global Energy Balance of a HSDI Diesel engine. Energy, 122, 168-181. doi:10.1016/j.energy.2017.01.082Payri, F., López, J. J., Martín, J., & Carreño, R. (2018). Improvement and application of a methodology to perform the Global Energy Balance in internal combustion engines. Part 1: Global Energy Balance tool development and calibration. Energy, 152, 666-681. doi:10.1016/j.energy.2018.03.11

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