Simulation Study of Cylinder-to-Cylinder Variation Phenomena and Key Influencing Factors in a Six-Cylinder Natural Gas Engine
Abstract
1. Introduction
2. Establishment of Simulation Platform and Design of Calculation Scheme
2.1. Establishment of Simulation Platform
2.2. Model Validation
2.3. Calculation Schemes
2.4. Evaluation Parameters for CTCV
2.4.1. Absolute Deviation
2.4.2. Relative Standard Deviation
3. Results and Discussion
3.1. Quantitative Analysis of CTCV Phenomena
3.2. Sensitivity Analysis of the Influencing Factors of CTCV
3.3. Comparative Analysis of CTCV at Two Engine Speeds
4. Conclusions and Outlook
- (1)
- For the test engine, the quantitative analysis of CTCV among cylinders was conducted by comparing various parameters, such as cylinder pressure, combustion phase, IMEP, intake charge mass, intake composition, the equivalence ratios, and TKE. There are obvious differences in the combustion process and performance parameters, which can be attributed to the comprehensive effects of the differences in many main boundary parameters between cylinders. Take cylinder 3 as an example: cylinder 3 exhibits higher initial TKE, a slightly richer mixture concentration, lower EGR, and the concentration distribution of rich at the top and lean at the bottom, leading to better combustion, with the shortest IDT and CA, and achieving the best power performance, with the highest peak pressure and IMEP.
- (2)
- By improving the mixture uniformity or distribution uniformity, the AD of intake charge mass, EGR rate, peak pressure, IMEP for all six cylinders decreased; meanwhile, the intake composition, the distribution of the equivalence ratio, and the turbulent kinetic energy of all six cylinders became more uniform. Comparing the influencing weight of mixture uniformity and distribution uniformity on the CTCV phenomenon, it was found that the RSD of all analyzed parameters decreases more significantly from case 1 to case 2 than from case 2 to case 3, which means that improving the mixture uniformity has a greater impact compared to improving the distribution uniformity. Take peak pressure as an example: the RSD of peak pressure is decreased by 2.15% by improving the mixture uniformity in case 2, while the RSD of peak pressure is decreased by 0.39% by improving the distribution uniformity in case 3.
- (3)
- The conclusions obtained at the 1800 rpm operating condition are in good agreement with those at the 1200 rpm operating condition. However, the high-speed condition shows an increase in the non-uniformity among cylinders. In addition, the improvement in distribution uniformity does enhance the mitigation of the CTCV phenomenon under the high-speed condition, but the influence of mixture uniformity remains the more significant factor affecting CTCV.
- (4)
- In this research, the mixture uniformity proved to be a more critical factor in improving the CTCV phenomenon. Subsequently, further studies on the influence of EGR mixture uniformity and NG mixture uniformity on CTCV will be compared.
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
Abbreviations
AMR | Adaptive Mesh Refinement |
AD | Absolute deviation |
BSFC | Brake-specific fuel consumption |
CFD | Computational fluid dynamics |
CTCV | Cylinder-to-cylinder variation |
CD | Combustion duration |
EGR | Exhaust gas recirculation |
IDT | Ignition delay time |
IMEP | Indicated mean effective pressure |
NG | Natural gas |
NOx | Nitrogen oxide |
PFI | Port fuel injection |
RSD | Relative standard deviation |
TKE | Turbulent kinetic energy |
TDC | Top dead center |
IC | Internal combustion |
References
- Gong, C.; Li, Z.; Yi, L.; Liu, F. Comparative study on combustion and emissions between methanol port-injection engine and methanol direct-injection engine with H2-enriched port-injection under lean-burn conditions. Energy Convers. Manag. 2019, 200, 112096. [Google Scholar] [CrossRef]
- Teoh, Y.H.; How, H.G.; Le, T.D.; Nguyen, H.T.; Loo, D.L.; Rashid, T.; Sher, F. A review on production and implementation of hydrogen as a green fuel in internal combustion engines. Fuel 2022, 333, 126525. [Google Scholar] [CrossRef]
- Tamilselvan, P.; Nallusamy, N.; Rajkumar, S. A comprehensive review on performance, combustion and emission characteristics of biodiesel fuelled diesel engines. Renew. Sustain. Energy Rev. 2017, 79, 1134–1159. [Google Scholar] [CrossRef]
- Chiong, M.-C.; Chong, C.T.; Ng, J.-H.; Mashruk, S.; Chong, W.W.F.; Samiran, N.A.; Mong, G.R.; Valera-Medina, A. Advancements of combustion technologies in the ammonia-fuelled engines. Energy Convers. Manag. 2021, 244, 114460. [Google Scholar] [CrossRef]
- Chai, W.S.; Bao, Y.; Jin, P.; Tang, G.; Zhou, L. A review on ammonia, ammonia-hydrogen and ammonia-methane fuels. Renew. Sustain. Energy Rev. 2021, 147, 111254. [Google Scholar] [CrossRef]
- Li, W.; Liu, Z.; Wang, Z. Experimental and theoretical analysis of the combustion process at low loads of a diesel natural gas dual-fuel engine. Energy 2016, 94, 728–741. [Google Scholar] [CrossRef]
- Wang, Z.; Su, X.; Wang, X.; Jia, D.; Wang, D.; Li, J. Impact of ignition energy on the combustion performance of an SI heavy-duty stoichiometric operation natural gas engine. Fuel 2022, 313, 122857. [Google Scholar] [CrossRef]
- Thiruvengadam, A.; Besch, M.; Padmanaban, V.; Pradhan, S.; Demirgok, B. Natural gas vehicles in heavy-duty transportation-A review. Energy Policy 2018, 122, 253–259. [Google Scholar] [CrossRef]
- Li, F.; Wang, Z.; Wang, Y.; Wang, B. High-Efficiency and Clean Combustion Natural Gas Engines for Vehicles. Automot. Innov. 2019, 2, 284–304. [Google Scholar] [CrossRef]
- Ding, S.-L.; Guo, B.; Liu, Z.-T.; Liu, J.-J.; Tunestål, P.; Song, E.-Z.; Cui, C. Analysis of the fractal characteristics for combustion instability in a premixed natural gas engine. Appl. Therm. Eng. 2023, 233, 121177. [Google Scholar] [CrossRef]
- You, J.; Liu, Z.; Wang, Z.; Wang, D.; Xu, Y. Impact of natural gas injection strategies on combustion and emissions of a dual fuel natural gas engine ignited with diesel at low loads. Fuel 2020, 260, 116414. [Google Scholar] [CrossRef]
- Tang, Q.; Fu, J.; Liu, J.; Zhou, F.; Yuan, Z.; Xu, Z. Performance improvement of liquefied natural gas (LNG) engine through intake air supply. Appl. Therm. Eng. 2016, 103, 1351–1361. [Google Scholar] [CrossRef]
- Shin, J.; Kim, D.; Son, Y.; Park, S. Effect of intake manifold geometry on cylinder-to-cylinder variation and tumble enhancement in gasoline direct injection engine. Sci. Rep. 2022, 12, 19862. [Google Scholar] [CrossRef] [PubMed]
- Kim, T.; Song, J.; Park, S. Effects of turbulence enhancement on combustion process using a double injection strategy in direct-injection spark-ignition (DISI) gasoline engines. Int. J. Heat Fluid Flow 2015, 56, 124–136. [Google Scholar] [CrossRef]
- Song, E.; Liu, Z.; Yang, L.; Yao, C.; Sun, J.; Dong, Q. Effects of nozzle structure on the gas mixture uniformity of marine gas engine. Ocean Eng. 2017, 142, 507–520. [Google Scholar] [CrossRef]
- Zhou, F.; Fu, J.; Shu, J.; Liu, J.; Wang, S.; Feng, R. Numerical simulation coupling with experimental study on the non-uniform of each cylinder gas exchange and working processes of a multi-cylinder gasoline engine under transient conditions. Energy Convers. Manag. 2016, 123, 104–115. [Google Scholar] [CrossRef]
- Yin, C.; Zhang, Z.; Sun, Y.; Sun, T.; Zhang, R. Effect of the piston top contour on the tumble flow and combustion features of a GDI engine with a CMCV: A CFD study. Eng. Appl. Comput. Fluid Mech. 2016, 10, 311–329. [Google Scholar] [CrossRef]
- Zhu, Z.; Mu, Z.; Wei, Y.; Du, R.; Guan, W.; Liu, S. Cylinder-to-cylinder variation of knock and effects of mixture formation on knock tendency for a heavy-duty spark ignition methanol engine. Energy 2022, 254, 124197. [Google Scholar] [CrossRef]
- Talati, H.; Aliakbari, K.; Ebrahimi-Moghadam, A.; Farokhad, H.K.; Nasrabad, A.E. Optimal design and analysis of a novel variable-length intake manifold on a four-cylinder gasoline engine. Appl. Therm. Eng. 2022, 200, 117631. [Google Scholar] [CrossRef]
- Babadi, M.N.; Kheradmand, S. The Effect of Using the Flow Separator Blade to Increase the Uniformity of Flow in the Intake Manifold. J. Mech. 2019, 35, 875–885. [Google Scholar] [CrossRef]
- Huang, C.-H.; Wang, C.-H.; Kim, S. A manifold design problem for a plate-fin microdevice to maximize the flow uniformity of system. Int. J. Heat Mass Transf. 2016, 95, 22–34. [Google Scholar] [CrossRef]
- Chen, Z.; Yao, C.; Wang, Q.; Han, G.; Dou, Z.; Wei, H.; Wang, B.; Liu, M.; Wu, T. Study of cylinder-to-cylinder variation in a diesel engine fueled with diesel/methanol dual fuel. Fuel 2016, 170, 67–76. [Google Scholar] [CrossRef]
- Czarnigowski, J. Analysis of cycle-to-cycle variation and non-uniformity of energy production: Tests on individual cylinders of a radial piston engine. Appl. Therm. Eng. 2011, 31, 1816–1824. [Google Scholar] [CrossRef]
- Chauvin, J.; Moulin, P.; Corde, G.; Petit, N.; Rouchon, P. Real-time nonlinear individual cylinder air-fuel ratio observer on a diesel engine test bench. IFAC Proc. Vol. (IFAC-Pap.) 2005, 38, 194–199. [Google Scholar] [CrossRef]
- Shi, M.; Jin, S.; Wang, J.; Zi, Z.; Chen, T.; Wu, B. Structural optimization study of ammonia-diesel dual-fuel engine based on reactivity turbulent jet disturbance coupled aerodynamics under high load conditions. Appl. Therm. Eng. 2024, 256, 124133. [Google Scholar] [CrossRef]
- Alrbai, M.I.; Qawasmeh, B.R. Evaluating the in-cylinder gas mixture homogeneity in natural gas HCCI free piston engine under different engine parameters using 3D-CFD analysis. Energy Sources, Part A: Recover. Util. Environ. Eff. 2018, 40, 1097–1113. [Google Scholar] [CrossRef]
- Muckova, P.; Kalabza, O.; Famfulik, J.; Smiraus, J.; Siroky, J.; Mikova, J. Engine intake airbox CFD optimisation and experimental validation tests. MM Sci. J. 2023, 03, 6364–6367. [Google Scholar] [CrossRef]
- Sakowitz, A.; Mihaescu, M.; Fuchs, L. Flow decomposition methods applied to the flow in an IC engine manifold. Appl. Therm. Eng. 2014, 65, 57–65. [Google Scholar] [CrossRef]
- Maiboom, A.; Tauzia, X.; Hétet, J.-F. Influence of EGR unequal distribution from cylinder to cylinder on NOx–PM trade-off of a HSDI automotive Diesel engine. Appl. Therm. Eng. 2009, 29, 2043–2050. [Google Scholar] [CrossRef]
- Dimitriou, P.; Burke, R.; Copeland, C.D.; Akehurst, S. Study on the Effects of EGR Supply Configuration on Cylin-der-to-Cylinder Dispersion and Engine Performance Using 1D-3D Co-Simulation; SAE Technical Paper; SAE International: Warrendale, PA, USA, 2015; Volume 32, pp. 816–827. [Google Scholar] [CrossRef]
- Reifarth, S.; Kristensson, E.; Borggren, J.; Sakowitz, A.; Angstrom, H.E. Analysis of EGR/Air Mixing by 1-D Simulation, 3-D Simulation and Experiments; SAE Technical Paper; SAE International: Warrendale, PA, USA, 2014; Volume 1, pp. 2647–2659. [Google Scholar] [CrossRef]
- Dhatkar, S.A.; Rajesh, S.K.; Garg, S.; Emran, A.; Sharma, V. EGR Mixer Optimization for Achieving Uniform Cylinder EGR Distribution Using 1D-3D CFD Coupled Simulation Approach to Meet Future Stage v Emission Legislation in India; SAE Technical Paper; SAE International: Warrendale, PA, USA, 2020; Volume 28, pp. 390–400. [Google Scholar] [CrossRef]
- Kassa, M.; Hall, C.; Ickes, A.; Wallner, T. Modeling and control of fuel distribution in a dual-fuel internal combustion engine leveraging late intake valve closings. Int. J. Engine Res. 2016, 18, 797–809. [Google Scholar] [CrossRef]
- Milojevic, S.; Savic, S.; Maric, D.; Stopka, O.; Krstic, B.; Stojanovic, B. Correlation between Emission and Combustion Characteristics with the Compression Ratio and Fuel Injection Timing in Tribologically Optimized Diesel Engine. Teh. Vjesn.-Tech. Gaz. 2022, 29, 1210–1219. [Google Scholar] [CrossRef]
- You, J.; Liu, Z.; Wang, Z.; Wang, D.; Xu, Y.; Du, G.; Fu, X. The exhausted gas recirculation improved brake thermal efficiency and combustion characteristics under different intake throttling conditions of a diesel/natural gas dual fuel engine at low loads. Fuel 2020, 266, 117035. [Google Scholar] [CrossRef]
- Wang, Y.; Xiao, F.; Zhao, Y.; Li, D.; Lei, X. Study on cycle-by-cycle variations in a diesel engine with dimethyl ether as port premixing fuel. Appl. Energy 2015, 143, 58–70. [Google Scholar] [CrossRef]
- Wu, G.; Ge, J.C.; Kim, M.S.; Choi, N.J. NOx–Smoke Trade-off Characteristics in a Palm Oil-Fueled CRDI Diesel Engine under Various Injection Pressures and EGR Rates. Appl. Sci. 2022, 12, 1069. [Google Scholar] [CrossRef]
Parameters | Value |
---|---|
Bore × stroke/mm | 127 × 165 |
Displacement/L | 13 |
Compression ratio | 11.6:1 |
Number of cylinders | 6 |
Ignition mode | Spark ignition |
Injection mode | Single point injection |
Encryption Type | Parameters | Value |
---|---|---|
AMR | Encryption region | Cylinders |
Max embedding level | 2 | |
Sub-grid criterion/K | 2.5 | |
Encryption interval/°CA ATDC | −20~60 | |
AMR | Encryption region | Intake port |
Max embedding level | 2 | |
Sub-grid criterion/m/s | 1 | |
Encryption interval | Injection duration | |
Fixed embedding | Encryption region | Spark plug |
Shape | Sphere | |
First encryption level | 5 | |
Second encryption level | 4 | |
Encryption interval/°CA ATDC | −20~−10 |
Name | Geometric Model Diagram | |
---|---|---|
Case 1 | Model of the original engine | |
Case 2 | Model for uniform mixing of gas mixture | |
Case 3 | Model for uniform mixing and uniform distribution of gas mixture |
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Jia, D.; Cao, Q.; Xu, X.; Wang, Z.; Wang, D.; Wang, H. Simulation Study of Cylinder-to-Cylinder Variation Phenomena and Key Influencing Factors in a Six-Cylinder Natural Gas Engine. Energies 2025, 18, 4078. https://doi.org/10.3390/en18154078
Jia D, Cao Q, Xu X, Wang Z, Wang D, Wang H. Simulation Study of Cylinder-to-Cylinder Variation Phenomena and Key Influencing Factors in a Six-Cylinder Natural Gas Engine. Energies. 2025; 18(15):4078. https://doi.org/10.3390/en18154078
Chicago/Turabian StyleJia, Demin, Qi Cao, Xiaoying Xu, Zhenlin Wang, Dan Wang, and Hongqing Wang. 2025. "Simulation Study of Cylinder-to-Cylinder Variation Phenomena and Key Influencing Factors in a Six-Cylinder Natural Gas Engine" Energies 18, no. 15: 4078. https://doi.org/10.3390/en18154078
APA StyleJia, D., Cao, Q., Xu, X., Wang, Z., Wang, D., & Wang, H. (2025). Simulation Study of Cylinder-to-Cylinder Variation Phenomena and Key Influencing Factors in a Six-Cylinder Natural Gas Engine. Energies, 18(15), 4078. https://doi.org/10.3390/en18154078