Numerical Analysis of the Effects of Fuel Injection Duration and Spray Angle on the Combustion Process in a Compression Ignition Engine

Abstract

The changes in injection strategies for diesel engines have a major impact on the performance and pollutant emission characteristics of diesel engines. If injection strategies like injection duration, injection timing, injection pressure and spray angle are properly adjusted, combustion can be improved. The engine performance will increase and emissions will decrease with the combustion improvement. In this work, the influences of injection duration and spray angle on the combustion characteristics of single cylinder, natural aspirated, electronically controlled injection, compression ignition engine were investigated. In the first stage of the work, experiments were executed on a single cylinder CI engine using a Cussons P8160 DC dynamometer. After the experiments, the piston bowl geometry of the engine was modeled and numerical simulation studies were achieved at 7 different injection durations and 7 different spray angles using Converge CFD software. As a result of this study, it was observed that there is a good match between experimental and simulation data of heat release rate (HRR) and in-cylinder pressure. In-cylinder pressure decreased with longer injection duration. The highest max. in-cylinder pressure was roughly 101.0 bar at 4°CA injection duration and the lowest max. in-cylinder pressure was roughly 82.0 bar at 10°CA injection duration. When the HRR data were analyzed, it was seen that as the injection duration increased, the amount of heat released by combustion decreased. When examining the results of the spray angle analysis, it was concluded that there were not very large differences in-cylinder pressure and HRR data, and there was a difference of 1.4 bar between the highest and lowest max. in-cylinder pressure values. In addition, the highest in-cylinder pressure of approximately 86.7 bar was obtained at a spray angle of 77°. It was observed that the CA50 value was obtained at angles closer to the top dead center by increasing the spray angle and decreasing the injection duration. Moreover, the longest combustion durations were realized at 60° spray angle and 10°CA injection duration.

Keywords

• Diesel Engine
• CFD
• Spray Angle
• Injection Duration

References

1. Amsden, A. A., & Findley, M. (1997). KIVA-3V: A block-structured KIVA program for engines with vertical or canted valves (First edition). Livermore: Lawrence Livermore National Lab.(LLNL), 1-95.
2. Basshuysen, V. R., & Schafer, F. (2004). Internal Combustion Engine Handbook Basics, Components, Systems and Prespectives (First edition). Warrendale, Pa.: SAE International, 390-412, 446-470.
3. Beale, J. C., & Reitz, R. D. (1999). Modeling spray atomization with the Kelvin-Helmholtz/Rayleigh-Taylor hybrid model. Atomization and Sprays, 9(6), 623-650. https://doi.org/10.1615/AtomizSpr.v9.i6.40
4. Cengiz, C., & Unverdi, S. O. (2023). A CFD Study on the Effects of Injection Timing and Spray Inclusion Angle on Performance and Emission Characteristics of a DI Diesel Engine Operating in Diffusion-Controlled and PCCI Modes of Combustion. Energies, 16(6), 2861. https://doi.org/10.3390/en16062861
5. Converge CFD Software. (2016). CONVERGE (v2.4) Theory Manual. Wisconsin: Convergent Science Inc., 298-316, 319-325, 335-337, 386-390, 479-520.
6. Du, W., Zhang, Q., Zhang, Z., Lou, J., & Bao, W. (2018). Effects of injection pressure on ignition and combustion characteristics of impinging diesel spray. Applied Energy, 226, 1163-1168. https://doi.org/10.1016/j.apenergy.2018.06.032
7. Ge, J. C., Wu, G., Yoo, B.-O., & Choi, N. J. (2022). Effect of injection timing on combustion, emission and particle morphology of an old diesel engine fueled with ternary blends at low idling operations. Energy, 253, 124150. https://doi.org/10.1016/j.energy.2022.124150
8. Gonzalez, D, M. A., Borman, G. L., & Reitz, R. D. (1991). A study of diesel cold starting using both cycle analysis and multidimensional calculations. SAE International Journal of Engines, 100(3), 189-208.

9. Gunaydin, S. (2022). The effect of dibutyl maleate addition to diesel fuel on engine performance and emissions. MSc Thesis, Afyon Kocatepe University.
10. Gupta, S. K., & Subramanian, K. A. (2022). Analysis of combustion and cycle to cycle variations of an ethanol (E100) fueled spark-ignition engine. International Journal of Automotive Science And Technology, 6(1), 68-74. https://doi.org/10.30939/ijastech..999559
11. Gurbuz, H., Buran, D., & Akcay, I. H. (2013). An experimental study on performance and cyclic variations in a spark ignition engine fuelled with hydrogen and gasoline. Journal of Thermal Science and Technology, 33(1), 33-41.
12. Halis, S., Solmaz, H., Polat, S., & Yücesu, H. S. (2022). Numerical Study of the Effects of Lambda and Injection Timing on RCCI Combustion Mode. International Journal of Automotive Science and Technology, 6(2), 120-126. https://doi.org/10.30939/ijastech..1105470
13. Hao, C., Zhang, Z., Wang, Z., Bai, H., Li, Y., Li, Y., & Lu, Z. (2022). Investigation of spray angle and combustion chamber geometry to improve combustion performance at full load on a heavy-duty diesel engine using genetic algorithm. Energy Conversion and Management, 267, 115862. https://doi.org/10.1016/j.enconman.2022.115862
14. Heywood, J. B. (2018). Internal combustion engine fundamentals. McGraw-Hill Education.
15. Huang, H., Zhu, Z., Zhu, J., Lv, D., Pan, Y., Wei, H., & Teng, W. (2019). Experimental and numerical study of pre-injection effects on diesel-n-butanol blends combustion. Applied Energy, 249, 377-391. https://doi.org/10.1016/j.apenergy.2019.04.163
16. Jaichandar, S., Kumar, P. S., & Annamalai, K. (2012). Combined effect of injection timing and combustion chamber geometry on the performance of a biodiesel fueled diesel engine. Energy, 47(1), 388-394. https://doi.org/10.1016/j.energy.2012.09.059
17. Jha, P. R., Wijeyakulasuriya, S., Krishnan, S. R., & Srinivasan, K. K. (2022). Numerical investigations of low load diesel-methane dual fuel combustion at early diesel injection timings. Fuel, 315, 123077. https://doi.org/10.1016/j.fuel.2021.123077
18. Jurić, F., Petranović, Z., Vujanović, M., Katrašnik, T., Vihar, R., Wang, X., & Duić, N. (2019). Experimental and numerical investigation of injection timing and rail pressure impact on combustion characteristics of a diesel engine. Energy Conversion and Management, 185, 730-739. https://doi.org/10.1016/j.enconman.2019.02.039
19. Khan, S., Panua, R., & Bose, P. K. (2018). Combined effects of piston bowl geometry and spray pattern on mixing, combustion and emissions of a diesel engine: A numerical approach. Fuel, 225, 203-217. https://doi.org/10.1016/j.fuel.2018.03.139
20. Kumar, M., Bhowmik, S., & Paul, A. (2022). Effect of pilot fuel injection pressure and injection timing on combustion, performance and emission of hydrogen-biodiesel dual fuel engine. International Journal of Hydrogen Energy, 47(68), 29554-29567. https://doi.org/10.1016/j.ijhydene.2022.06.260
21. Lu, Y., Fan, C., Chen, Y., Liu, Y., & Pei, Y. (2023). Effect of injection strategy optimization on PCCI combustion and emissions under engine speed extension in a heavy-duty diesel engine. Fuel, 332, 126053. https://doi.org/10.1016/j.fuel.2022.126053
22. Mehta, P. S., & Tamma, B. (1998). Effect of swirl and fuel injection characteristics on premixed phase of diesel combustion. International Congress and Exposition, Detroit Michigan, SAE Technical Paper 980534. https://doi.org/10.4271/980534
23. Mishra, A., Kulshrestha, S., Patel, F. M., Tiwari, N., & Sharma, A. (2023). Effect of piston bowl geometry and spray angle on engine performance and emissions in HCCI engine using multi‐stage injection strategy. Environmental Progress & Sustainable Energy, e14203. https://doi.org/10.1002/ep.14203
24. Mohan, B., Yang, W., Tay, K. L., & Yu, W. (2014). Experimental study of spray characteristics of biodiesel derived from waste cooking oil. Energy Conversion and Management, 88, 622-632. https://doi.org/10.1016/j.enconman.2014.09.013
25. Pham, V. C., Le, V. V., Yeo, S., Choi, J.-H., & Lee, W.-J. (2022). Effects of the Injector Spray Angle on Combustion and Emissions of a 4-Stroke Natural Gas-Diesel DF Marine Engine. Applied Sciences, 12(23), 11886. https://doi.org/10.3390/app122311886
26. Ranganatha Swamy, L., Chandrashekar, T. K., Banapurmath, N. R., & Nashipudi, P. (2014). Effect of injection timing, combustion chamber shapes and nozzle geometry on the diesel engine performance. Universal Journal of Petroleum Sciences, 2, 74-95.
27. Schmidt, D. P., & Rutland, C. J. (2000). A new droplet collision algorithm. Journal of Computational Physics, 164(1), 62-80. https://doi.org/10.1006/jcph.2000.6568
28. Sener, R., Yangaz, M. U., & Gul, M. Z. (2020). Effects of injection strategy and combustion chamber modification on a single-cylinder diesel engine. Fuel, 266, 117122. https://doi.org/10.1016/j.fuel.2020.117122
29. Sener, R. (2022). Numerical Investigation of Ducted Fuel Injection Strategy for Soot Reduction in Compression Ignition Engine. Journal of Applied Fluid Mechanics, 15(2), 475-489. https://doi.org/10.47176/jafm.15.02.33088
30. Shu, J., Fu, J., Liu, J., Ma, Y., Wang, S., Deng, B., & Zeng, D. (2019). Effects of injector spray angle on combustion and emissions characteristics of a natural gas (NG)-diesel dual fuel engine based on CFD coupled with reduced chemical kinetic model. Applied Energy, 233-234, 182-195. https://doi.org/10.1016/j.apenergy.2018.10.040
31. Sanli, A., Yilmaz, I. T., & Gumus, M. (2023). Effects of Thermal Barrier Coated Piston on Performance and Combustion Characteristics in Dual-Fuel Common-Rail Diesel Engine. International Journal of Automotive Science and Technology, 7(2), 141-153. https://doi.org/10.30939/ijastech..1268355
32. Turns, S. R. (1996). Introduction to combustion. New York, NY, USA: McGraw-Hill Companies, 568-569.
33. Wei, S., Ji, K., Leng, X., Wang, F., & Liu, X. (2014). Numerical simulation on effects of spray angle in a swirl chamber combustion system of DI (direct injection) diesel engines. Energy, 75, 289-294. https://doi.org/10.1016/j.energy.2014.07.076
34. Yakhot, V., & Orszag, S. A. (1986). Renormalization group analysis of turbulence. I. Basic theory. Journal of Scientific Computing, 1(1), 3-51. https://doi.org/10.1007/BF01061452
35. Yousefi, A., Guo, H., & Birouk, M. (2018). An experimental and numerical study on diesel injection split of a natural gas/diesel dual-fuel engine at a low engine load. Fuel, 212, 332-346. https://doi.org/10.1016/j.fuel.2017.10.053