Strategies to achieve controlled auto-ignition (CAI) combustion: A review

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Ibham Veza
Indra C. Setiawan
La Ode M. Firman
Handi Handi
Ayu Amanah
Mega T. Kurnia
Permana A. Paristiawan
Muhammad Idris
Ahmed Sule
Anthony C. Opia


Conventional gasoline engines suffer from low performance and NOx emissions.  Controlled auto-ignition (CAI), sometimes referred to as homogeneous charge compression ignition (HCCI), is a promising concept to solve such problems. CAI has the potential to improve spark ignition (SI) engine fuel economy while at the same time solving the trade-off of NOx-soot emissions found in compression ignition (CI) engines. The CAI engine can reach a fuel economy comparable to that of a conventional diesel engine with ultra-low NOx and negligible soot emissions. However, controlling auto-ignition remains the biggest difficulty that hinders the implementation of CAI as a commercial engine. Research towards a cleaner and more efficient engine is driven by the progressively stringent emission regulation imposed worldwide. Therefore, the CAI was developed to meet the emissions target while maintaining engine performance. CAI works on the principle of lean mixture and auto-ignition. To obtain CAI combustion, the temperatures in the cylinder must be sufficient to initiate auto-ignition. Without the use of a spark plug or injector, the CAI suffers from a direct control mechanism to start the combustion. The most practical approach to controlling the initiation of auto-ignition in CAI is diluting the intake charge by either trapping the residual gas or recirculating the exhaust gas. Both approaches enable the engine to achieve CAI combustion without requiring significant modifications to control the onset of CAI combustion phase.


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[1] I. Veza, M. F. Roslan, M. F. M. Said, and Z. A. Latiff, “Potential of range extender electric vehicles (REEVS),” in IOP Conference Series: Materials Science and Engineering, 2020, vol. 884, no. 1, p. 12093, doi: 10.1088/1757-899X/884/1/012093.
[2] I. Veza et al., “Electric Vehicles in Malaysia and Indonesia: Opportunities and Challenges,” Energies, vol. 15, no. 7, p. 2564, 2022, doi: 10.3390/en15072564.
[3] Z. P. Cano et al., “Batteries and fuel cells for emerging electric vehicle markets,” Nature Energy, vol. 3, no. 4, pp. 279–289, 2018.
[4] S. M. N. Rahaju et al., “Acetone-Butanol-Ethanol as the Next Green Biofuel-A Review,” Automotive Experiences, vol. 5, no. 3, pp. 251–260, 2022.
[5] I. Veza et al., “Lessons from Brazil: Opportunities of Bioethanol Biofuel in Indonesia,” Indonesian Journal of Computing, Engineering and Design (IJoCED), vol. 4, no. 1, pp. 8–16, 2022.
[6] M. Q. Rusli et al., “Performance and emission measurement of a single cylinder diesel engine fueled with palm oil biodiesel fuel blends,” in IOP Conference Series: Materials Science and Engineering, 2021, vol. 1068, no. 1, p. 12020, doi: 10.1088/1757-899X/1068/1/012020.
[7] D. N. Cao, A. T. Hoang, H. Q. Luu, V. G. Bui, and T. T. H. Tran, “Effects of injection pressure on the NOx and PM emission control of diesel engine: A review under the aspect of PCCI combustion condition,” Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, pp. 1–18, 2020.
[8] A. Dimitriadis et al., “Improving PM-NOx trade-off with paraffinic fuels: A study towards diesel engine optimization with HVO,” Fuel, vol. 265, p. 116921, 2020.
[9] M. A. Fayad, B. R. AL-Ogaidi, M. K. Abood, and H. A. AL-Salihi, “Influence of post-injection strategies and CeO2 nanoparticles additives in the C30D blends and diesel on engine performance, NOX emissions, and PM characteristics in diesel engine,” Particulate Science and Technology, vol. 40, no. 7, pp. 824–837, 2022.
[10] R. Suarez-Bertoa et al., “On-road emissions of passenger cars beyond the boundary conditions of the real-driving emissions test,” Environmental research, vol. 176, p. 108572, 2019.
[11] F. Leach et al., “A Review and Perspective on Particulate Matter Indices Linking Fuel Composition to Particulate Emissions from Gasoline Engines,”,” SAE Int. J. Fuels Lubr., vol. 15, no. 1, 2022.
[12] C. K. Lambert, “Current state of the art and future needs for automotive exhaust catalysis,” Nature Catalysis, vol. 2, no. 7, pp. 554–557, 2019.
[13] J. D. Smith et al., “Real-time particulate emissions rates from active and passive heavy-duty diesel particulate filter regeneration,” Science of The Total Environment, vol. 680, pp. 132–139, 2019.
[14] A. Kozina, G. Radica, and S. Nižetić, “Analysis of methods towards reduction of harmful pollutants from diesel engines,” Journal of Cleaner Production, vol. 262, p. 121105, 2020.
[15] T. Selleri, A. D. Melas, A. Joshi, D. Manara, A. Perujo, and R. Suarez-Bertoa, “An overview of lean exhaust denox aftertreatment technologies and nox emission regulations in the european union,” Catalysts, vol. 11, no. 3, p. 404, 2021.
[16] M. F. Roslan, I. Veza, and M. F. M. Said, “Predictive simulation of single cylinder n-butanol HCCI engine,” in IOP conference series: Materials science and engineering, 2020, vol. 884, no. 1, p. 12099, doi: 10.31224/
[17] I. Veza et al., “Strategies to Form Homogeneous Mixture and Methods to Control Auto-Ignition of HCCI Engine,” International Journal of Automotive and Mechanical Engineering, vol. 18, no. 4, pp. 9253–9270, 2021, doi: 10.15282/ijame.18.4.2021.09.0712.
[18] U. Azimov, E. Tomita, N. Kawahara, and Y. Harada, “Premixed mixture ignition in the end-gas region (PREMIER) combustion in a natural gas dual-fuel engine: operating range and exhaust emissions,” International Journal of Engine Research, vol. 12, no. 5, pp. 484–497, 2011.
[19] H. R. Chauhan, K. Preksha, S. K. Dabhi, and V. G. Trivedi, “A Technical Review HCCI Combustion in Diesel Engine,” International Journal for Innovative Research in Science & Technology, vol. 1, no. 10, 2015.
[20] A. K. Agarwal, A. P. Singh, and R. K. Maurya, “Evolution, challenges and path forward for low temperature combustion engines,” Progress in energy and combustion science, vol. 61, pp. 1–56, 2017.
[21] J. Valero-Marco, B. Lehrheuer, J. J. López, and S. Pischinger, “Potential of water direct injection in a CAI/HCCI gasoline engine to extend the operating range towards higher loads,” Fuel, vol. 231, pp. 317–327, 2018.
[22] A. K. Oppenheim, Combustion in piston engines: technology, evolution, diagnosis and control. Springer, 2004.
[23] N. Gombosuren, “Ultra-Lean Combustion of SI Engine Using Alternative Stratification Principles,” 2020.
[24] H. Zhao, HCCI and CAI engines for the automotive industry. Elsevier, 2007.
[25] M. Izadi Najafabadi and N. Abdul Aziz, “Homogeneous charge compression ignition combustion: challenges and proposed solutions,” Journal of combustion, vol. 2013, 2013.
[26] H. Zhao, “Overview of CAI/HCCI gasoline engines,” in HCCI and CAI engines for the automotive industry, Elsevier, 2007.
[27] S. Wiemann, R. Hegner, B. Atakan, C. Schulz, and S. A. Kaiser, “Combined production of power and syngas in an internal combustion engine–Experiments and simulations in SI and HCCI mode,” Fuel, vol. 215, pp. 40–45, 2018.
[28] C. Cinar, A. Uyumaz, H. Solmaz, and T. Topgul, “Effects of valve lift on the combustion and emissions of a HCCI gasoline engine,” Energy Conversion and Management, vol. 94, pp. 159–168, 2015.
[29] A. Calam, “Effects of the fusel oil usage in HCCI engine on combustion, performance and emission,” Fuel, vol. 262, p. 116503, 2020.
[30] J. Hunicz, M. Mikulski, M. S. Geca, and A. Rybak, “An applicable approach to mitigate pressure rise rate in an HCCI engine with negative valve overlap,” Applied Energy, vol. 257, p. 114018, 2020.
[31] J. Hunicz, “An experimental study of negative valve overlap injection effects and their impact on combustion in a gasoline HCCI engine,” Fuel, vol. 117, pp. 236–250, 2014.
[32] Y. Zhang and H. Zhao, “Investigation of combustion, performance and emission characteristics of 2-stroke and 4-stroke spark ignition and CAI/HCCI operations in a DI gasoline,” Applied energy, vol. 130, pp. 244–255, 2014.
[33] J.-O. Olsson, P. Tunestål, G. Haraldsson, and B. Johansson, “A turbo charged dual fuel HCCI engine,” SAE Special Publications (Vol. 2001), vol. 1, no. 1896, p. 1896, 2001.
[34] H. Zhao, J. Li, T. Ma, and N. Ladommatos, “Performance and analysis of a 4-stroke multi-cylinder gasoline engine with CAI combustion,” 2002.
[35] S. H. Jo, P. Do Jo, T. Gomi, and S. Ohnishi, “Development of a low-emission and high-performance 2-stroke gasoline engine (NiCE),” SAE Transactions, pp. 1425–1433, 1973.
[36] S. Onishi, S. H. Jo, K. Shoda, P. Do Jo, and S. Kato, “Active thermo-atmosphere combustion (ATAC)—a new combustion process for internal combustion engines,” SAE Transactions, pp. 1851–1860, 1979.
[37] M. Noguchi, Y. Tanaka, T. Tanaka, and Y. Takeuchi, “A study on gasoline engine combustion by observation of intermediate reactive products during combustion,” SAE Transactions, pp. 2816–2828, 1979.
[38] Y. Ishibashi and M. Asai, “Improving the exhaust emissions of two-stroke engines by applying the activated radical combustion,” SAE transactions, pp. 982–992, 1996.
[39] N. N. Semenov, “Chemical kinetics and chain reactions,” 1935.
[40] L. A. Gussak, V. P. Karpov, and Y. V Tikhonov, “The application of lag-process in prechamber engines,” SAE Transactions, pp. 2355–2380, 1979.
[41] L. A. Gussak, “High chemical activity of incomplete combustion products and a method of prechamber torch ignition for avalanche activation of combustion in internal combustion engines,” SAE transactions, pp. 2421–2445, 1975.
[42] P. M. Najt and D. E. Foster, “Compression-ignited homogeneous charge combustion,” SAE Transactions, pp. 964–979, 1983.
[43] R. H. Thring, “Homogeneous-charge compression-ignition (HCCI) engines,” SAE Technical paper, 1989.
[44] A. Khameneian et al., “Model-based dynamic in-cylinder air charge, residual gas and temperature estimation for a gdi spark ignition engine using cylinder, intake and exhaust pressures,” ASME 2020 Dynamic Systems and Control Conference, DSCC 2020, vol. 2, no. January, 2020, doi: 10.1115/DSCC2020-3280.
[45] A. Khameneian et al., “A real-time control-oriented discrete nonlinear model development for in-cylinder air charge, residual gas and temperature prediction of a Gasoline Direct Injection engine using cylinder, intake and exhaust pressures,” Control Engineering Practice, vol. 119, p. 104978, 2022.
[46] T. D. M. Lanzanova, M. Dalla Nora, M. E. S. Martins, P. R. M. Machado, V. B. Pedrozo, and H. Zhao, “The effects of residual gas trapping on part load performance and emissions of a spark ignition direct injection engine fuelled with wet ethanol,” Applied Energy, vol. 253, p. 113508, 2019.
[47] N. X. Khoa, Y. Q. Nhu, and O. Lim, “Estimation of parameters affected in internal exhaust residual gases recirculation and the influence of exhaust residual gas on performance and emission of a spark ignition engine,” Applied Energy, vol. 278, p. 115699, 2020.
[48] B. P. Maldonado and B. C. Kaul, “Evaluation of residual gas fraction estimation methods for cycle-to-cycle combustion variability analysis and modeling,” International Journal of Engine Research, vol. 23, no. 2, pp. 198–213, 2022.
[49] M. Parthasarathy et al., “Performance analysis of HCCI engine powered by tamanu methyl ester with various inlet air temperature and exhaust gas recirculation ratios,” Fuel, vol. 282, p. 118833, 2020.
[50] K. Ali, C. Kim, Y. Lee, S. Oh, and K. Kim, “A numerical study to control the combustion performance of a syngas-fueled HCCI engine at medium and high loads using different piston bowl geometry and exhaust gas recirculation,” Journal of Energy Resources Technology, vol. 143, no. 8, 2021.
[51] M. A. Rather and M. M. Wani, “A numerical study on the effects of exhaust gas recirculation temperature on controlling combustion and emissions of a diesel engine running on HCCI combustion mode,” International Journal of Automotive Science and Technology, vol. 2, no. 3, pp. 17–27, 2018.
[52] M. A. Rather and M. M. Wani, “Computational study on the effects of exhaust gas recirculation on thermal and emission characteristics of HCCI diesel engine,” Automotive Science and Engineering, vol. 8, no. 4, pp. 2833–2839, 2018.
[53] F. A. Herzer, J. L. S. Fagundez, M. E. S. Martins, and N. P. G. Salau, “Chemical kinetic mechanisms for HCCI combustion of wet ethanol with exhaust gas recirculation,” SAE Technical Paper, 2020.
[54] C. Cinar, A. Uyumaz, H. Solmaz, F. Sahin, S. Polat, and E. Yilmaz, “Effects of intake air temperature on combustion, performance and emission characteristics of a HCCI engine fueled with the blends of 20% n-heptane and 80% isooctane fuels,” Fuel Processing Technology, vol. 130, pp. 275–281, 2015.
[55] C. H. Lee and K. H. Lee, “An experimental study of the combustion characteristics in SCCI and CAI based on direct-injection gasoline engine,” Experimental Thermal and Fluid Science, vol. 31, no. 8, pp. 1121–1132, 2007.

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