Effects of Friction Loss Models and Cycle Parameters on the Performance of the Irreversible Dual-Miller Cycle

Kum Song Choe; Yong Jae Min; Sang Dok Ri; Myong Chol Ri

doi:doi:10.11648/j.ijfmts.20251103.11

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Effects of Friction Loss Models and Cycle Parameters on the Performance of the Irreversible Dual-Miller Cycle

Kum Song Choe, Yong Jae Min^*

, Sang Dok Ri, Myong Chol Ri

Published in International Journal of Fluid Mechanics & Thermal Sciences (Volume 11, Issue 3)

Received: 1 July 2025 Accepted: 22 July 2025 Published: 25 August 2025

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Abstract

Since the effects of various irreversible losses and cycle conditions on the internal combustion engine performance are significant, it is important to compare the effects of the parameters on the performance in a cycle study. Thermodynamic cycle studies should take into account the irreversible losses such as internal irreversibility, friction losses, heat transfer losses, and the variation of the specific heat of the working fluid. This study aims at deriving the analytic equation with respect to ecological function of the irreversible Dual-Miller cycle (DMC) by using the specific heat model of polynomial, and comparing results of performance calculation of different friction losses, and analyzing the effect of the cycle parameters for optimum performance. The calculation results show that the friction loss has a considerable influence on the engine performance, but there is no significant difference in the choice of the cycle parameters for optimum performance. It is also found that optimizing the ecological function is an effective way to simultaneously increase the power and efficiency, and the friction loss is not affected. The cut-off ratio, which gives the ecological function maximum, is between the cut-off ratio, which gives the power and efficiency maximum, and the Miller cycle ratio, respectively, which is closer to the efficiency maximum. The Miller cycle ratio that maximizes performance is slightly larger than the cut-off ratio. The presented models and results are expected to provide guidelines for the design and optimization of DMC engines, and for the performance improvement and to perform the cycle modeling close to the cycle of the actual engine.

Published in	International Journal of Fluid Mechanics & Thermal Sciences (Volume 11, Issue 3)
DOI	10.11648/j.ijfmts.20251103.11
Page(s)	33-49
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2025. Published by Science Publishing Group

Keywords

Dual-Miller Cycle, Friction Loss, Ecological Function, Irreversible Loss, Cycle Parameter

References

[1]	Y. L. Ge, L. G. Chen, F. R. Sun, Progress in finite time thermodynamic studies for internal combustion engine cycles, Entropy 18(4) (2016) 139. https://doi.org/10.3390/e18040139
[2]	Ge Y, Wu H, Chen L, et al. Finite time and finite speed thermodynamic optimization for an irreversible Atkinson cycle. Energy, 2023, 270: 126856.
[3]	Andresen, B.; Salamon, P. Future perspectives of finite-time thermodynamics. Entropy 2022, 24, 690.
[4]	C. Q. Li, Y. D. Wang, B. Jia, A. P. Roskilly, Application of Miller cycle with turbocharger and ethanol to reduce NOx and particulates emissions from diesel engine - A numerical approach with model validations, Appl. Therm. Eng. 150(2019) 904-911. https://doi.org/10.1016/j.applthermaleng.2019.01.056
[5]	Gonca. G, Thermodynamic analysis and performance maps for the irreversible Dual-Atkinson cycle engine (DACE) with considerations of temperature-dependent specific heats, heat transfer and friction losses, Energy Convers. Manage. 111(2016) 205-216. https://doi.org/10.1016/j.enconman.2015.12.059
[6]	Wang P, Tang X, Shi L, Ni X, Hu Z, Deng K (2021) Experimental investigation of the influences of Miller cycle combined with EGR on performance, energy and exergy characteristics of a four-stroke marine regulated two-stage turbocharged diesel engine. Fuel 300, 120940. https://doi.org/10.1016/j.fuel.2021.120940
[7]	Chen, L., Zhu, F., Shi, S. et al. Power and efficiency optimizations of Maisotsenko-Atkinson, Dual and Miller cycles and performance comparisons with corresponding traditional cycles. Sci. China Technol. Sci. 66, 3393-3411 (2023). https://doi.org/10.1007/s11431-023-2444-1
[8]	Zang, P. C.; Chen, L. G.; Ge, Y. L.; Shi, S. S. Four-objective optimization for an irreversible porous medium cycle with linear variation in working fluid’s specific heat. Entropy 2022, 24, 1074.
[9]	Ahmadi, M. H.; Pourkiaei, S. M.; Ghazvini, M.; Pourfayaz, F. Thermodynamic assessment and optimization of performance of irreversible Atkinson cycle. Iran. J. Chem. Chem. Eng. 2020, 39, 267-280.
[10]	Georgiou C, Azimov U (2020) Analysis and multi-parametric optimisation of the performance and exhaust gas emissions of a heavy-duty diesel engine operating on miller cycle. Energies 13(14): 3724. https://doi.org/10.3390/en13143724
[11]	Zerom M, Gonca. G (2020) Multi-criteria performance analysis of dual miller cycle-Organic rankine cycle combined power plant. Energy Conversion Management 221, 113121. https://doi.org/10.1016/j.enconman.2020.113121
[12]	Shengli Wei, Chengcheng Wu, Shuzhe Yan, Tongyuan Ding, Jie Chen (2022). Miller Cycle with Early Intake Valve Closing in Marine Medium-Speed Diesel Engines. Journal of Marine Science and Application, 21(1): 151-160. https://doi.org/10.1007/s11804-022-00250-5
[13]	Ge, Y.; Chen, L.; Sun, F. Performance of an Atkinson cycle with heat transfer, friction and variable specific-heats of the working fluid. Appl. Energy 2006, 83, 1210-1221. https://doi.org/10.1016/j.apenergy.2005.12.003
[14]	Y. R. Zhao, J. C. Chen, Performance analysis of an irreversible Miller heat engine and its optimum criteria, Appl. Therm. Eng. 27(11-12) (2007) 2051-2058. https://doi.org/10.1016/j.applthermaleng.2006.12.002
[15]	A. Mousapour and M. M. Rashidi, Performance Evaluation of an Air-Standard Miller Cycle with Consideration of Heat Losses, International Journal of Mechatronics, Electrical and Computer Technology, Vol. 4(12) (2014) 1175-1191.
[16]	Gonca. G, Sahin. B, Ust. Y, Performance maps for an air-standard irreversible Dual-Miller cycle (DMC) with late inlet valve closing (LIVC) version, Energy 54(2013) 285-290. https://doi.org/10.1016/j.energy.2013.02.004
[17]	Y. Ust, F. Arslan, I. Ozsari, M. Cakir, Thermodynamic performance analysis and optimization of DMC (Dual Miller Cycle) cogeneration system by considering exergetic performance coefficient and total exergy output criteria, Energy 90(2015) 552-559. https://doi.org/10.1016/j.energy.2015.07.081
[18]	Gonca. G, Sahin. B, Ust. Y, Parlak. A, Comprehensive performance analyses and optimization of the irreversible thermodynamic cycle engines (TCE) under maximum power (MP) and maximum power density (MPD) conditions. Appl. Therm. Eng. 85(2015) 9-20. https://doi.org/10.1016/j.applthermaleng.2015.02.041
[19]	Gonca. G, Sahin. B, Ust. Y, Investigation of Heat Transfer Influences on Performance of Air-Standard Irreversible Dual-Miller Cycle. Journal of Thermophysics and Heat Transfer 29(2015) 678-693. https://doi.org/10.2514/1.T4512
[20]	M. CAKIR, THE NUMERICAL THERMODYNAMIC ANALYSIS OF OTTO-MILLER CYCLE, THERMAL SCIENCE: 20(2016) 363-369. https://doi.org/10.2298/TSCI150623131C
[21]	Gonca. G, Sahin. B, Thermo-ecological performance analyses and optimizations of irreversible gas cycle engines, Appl. Therm. Eng. 105(2016) 566-576. https://doi.org/10.1016/j.applthermaleng.2016.03.046
[22]	Gonca. G, Comparative performance analyses of irreversible OMCE (Otto Miller cycle engine)-DiMCE (Diesel miller cycle engine)-DMCE (Dual Miller cycle engine), Energy 109(2016) 152-159. https://doi.org/10.1016/j.energy.2016.04.049
[23]	R. Ebrahimi, A new design method for maximizing the work output of cycles in reciprocating internal combustion engines, Energy Convers. Manage. 172(2018) 164-172. https://doi.org/10.1016/j.enconman.2018.07.029
[24]	Z. X. Wu, L. G. Chen, H. J. Feng, Thermodynamic Optimization for an Endoreversible Dual-Miller Cycle (DMC) with Finite Speed of Piston, Entropy 20(2018) 165. https://doi.org/10.3390/e20030165
[25]	Y. UST, I. OZSARI, F. ARSLAN, A. SAFA, A THEORETICAL PERFORMANCE INVESTIGATION OF IRREVERSIBLE INTERNAL COMBUSTION ENGINE NAMED AS DUAL-MILLER CYCLE Sigma J Eng & Nat Sci 38(1) (2020) 459-473.
[26]	J. You, L. G. Chen, Z. X. Wu, F. R. Sun, Thermodynamic performance of DualMiller cycle (DMC) with polytropic processes based on power output, thermal efficiency and ecological function, Sci. China: Tech. Sci. 61(3) (2018) 453-463.
[27]	S. Abedinnezhad, M. H. Ahmadi, S. M. Pourkiaei, F. Pourfayaz, A. Mosavi, M. Feidt, S. Shamshirband, Thermodynamic Assessment and Multi-Objective Optimization of Performance of Irreversible Dual-Miller Cycle, Energies 12(4000) (2019) 1-25.
[28]	A. Al-Sarkhi, J. Jaber, S. Probert, Efficiency of a Miller engine, Appl. Energ. 83(4) (2006) 343-351. https://doi.org/10.1016/j.apenergy.2005.04.003
[29]	A. Al-Sarkhi, I. Al-Hinti, E. Abu-Nada, B. Akash, Performance evaluation of irreversible Miller engine under various specific heat models, Int. Comm. Heat Mass Transfer 34(7) (2007) 897-906. https://doi.org/10.1016/j.icheatmasstransfer.2007.03.012
[30]	J. C. Lin, S. S. Hou, Performance analysis of an air-standard Miller cycle with considerations of heat loss as a percentage of fuel's energy, friction and variable specific heats of working fluid, Int. J. Therm. Sci. 47(2) (2008) 182-191.
[31]	X. M. YE, Effect of variable heat capacities on performance of an irreversible Miller heat engine, Energy. 6(3) (2012) 280-284.
[32]	R. Ebrahimi, M. Hoseinpour, Performance Analysis of Irreversible Miller Cycle Under Variable Compression Ratio, JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER 27(3) (2013)542-548.
[33]	J. M. Lin, Z. P. Xu, S. Q. Chang, H. Yan, Finite-time thermodynamic modelling and analysis of an irreversible Miller cycle working on a four-stroke engine, Int. Comm. Heat Mass Transfer 54(2014) 54-59. https://doi.org/10.1016/j.icheatmasstransfer.2014.03.012
[34]	E. Dobrucali, The effects of the engine design and running parameters on the performance of a Otto-Miller Cycle engine, Energy 103(2016) 119-126.
[35]	G. Gonca, AN OPTIMIZATION STUDY ON AN ECO-FRIENDLY ENGINE CYCLE NAMED AS DUAL-MILLER CYCLE (DMC) FOR MARINE VEHICLES, POLISH MARITIME RESEARCH 24(2017) 86-98.
[36]	Gonca. G, B. Sahin, Effect of turbo charging and steam injection methods on the performance of a Miller cycle diesel engine (MCDE). Appl. Therm. Eng. 118(2017) 138-146. https://doi.org/10.1016/j.applthermaleng.2017.02.039
[37]	Y. L. Ge, L. G. Chen, X. Y. Qin, Effect of specific heat variations on irreversible Otto cycle performance, Int. J. Heat Mass Transf 122(2018) 403-409. https://doi.org/10.1016/j.ijheatmasstransfer.2018.01.132
[38]	R. Ebrahimi, Thermodynamic modeling of performance of a Miller cycle with engine speed and variable specific heat ratio of working fluid, Comput. Math. Appl. 62(5) (2011) 2169-2176.
[39]	Z. J. Yan, Comment on ‘‘ecological optimization criterion for finite-time heat engines”, J. Appl. Phys. 73(7) (1993) 3583.
[40]	Gonca. G, Thermo-ecological analysis of irreversible Dual-Miller cycle (DMC) engine based on the ecological coefficient of performance (ECOP) criterion, Iran. J. Sci. Technol. Trans. Mech. Eng. 41(4) (2017) 269-280.
[41]	Z. X. Wu, L. G. Chen, Y. L. Ge, F. R. Sun, Thermodynamic optimization for an air-standard irreversible Dual-Miller cycle with linearly variable specific heat ratio of working fluid, Int. J. Heat Mass Transf 124(2018) 46-57. https://doi.org/10.1016/j.ijheatmasstransfer.2018.03.049
[42]	Z. X. Wu, L. G. Chen, Y. L. Ge, F. R. Sun, Power, efficiency, ecological function and ecological coefficient of performance of an irreversible Dual-Miller cycle (DMC) with nonlinear variable specific heat ratio of working fluid, Eur. Phys. J. Plus 132(5) (2017) 203.
[43]	L. G. Chen, Y. L. Ge, C. Liu, H. J. Feng, G. L. Lorenzini, Performance of Universal Reciprocating Heat-Engine Cycle with Variable Specific Heats Ratio of Working Fluid, Entropy 22(397) (2020) 1-13. https://doi.org/10.3390/e22040397
[44]	Gonca. G., Hocaoglu, M. F. Performance Analysis and Simulation of a Diesel-Miller Cycle (DiMC) Engine. Arab J Sci Eng 44, 5811-5824 (2019). https://doi.org/10.1007/s13369-019-03747-4
[45]	Zhao, J.; Li, Y.; Xu, F. The effects of the engine design and operation parameters on the performance of an Atkinson engine considering heat-transfer, friction, combustion efficiency and variable specific-heat. Energy Convers. Manag. 2017, 151, 11-22. https://doi.org/10.1016/j.enconman.2017.08.066
[46]	Zhao, J., Xu, F. Finite-Time Thermodynamic Modeling and a Comparative Performance Analysis for Irreversible Otto, Miller and Atkinson Cycles, Entropy 2018, 20, 75. https://doi.org/10.3390/e20010075
[47]	Heywood JB. Internal combustion engine fundamentals. New York: McGraw-Hill Book Company; 1988.
[48]	Chen, S. K., Flynn, P. F., Development of a Single Cylinder Compression Ignition Research Engine, SAE Paper 650733, 1965.

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APA Style

Choe, K. S., Min, Y. J., Ri, S. D., Ri, M. C. (2025). Effects of Friction Loss Models and Cycle Parameters on the Performance of the Irreversible Dual-Miller Cycle. International Journal of Fluid Mechanics & Thermal Sciences, 11(3), 33-49. https://doi.org/10.11648/j.ijfmts.20251103.11

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ACS Style

Choe, K. S.; Min, Y. J.; Ri, S. D.; Ri, M. C. Effects of Friction Loss Models and Cycle Parameters on the Performance of the Irreversible Dual-Miller Cycle. Int. J. Fluid Mech. Therm. Sci. 2025, 11(3), 33-49. doi: 10.11648/j.ijfmts.20251103.11

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AMA Style

Choe KS, Min YJ, Ri SD, Ri MC. Effects of Friction Loss Models and Cycle Parameters on the Performance of the Irreversible Dual-Miller Cycle. Int J Fluid Mech Therm Sci. 2025;11(3):33-49. doi: 10.11648/j.ijfmts.20251103.11

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@article{10.11648/j.ijfmts.20251103.11,
  author = {Kum Song Choe and Yong Jae Min and Sang Dok Ri and Myong Chol Ri},
  title = {Effects of Friction Loss Models and Cycle Parameters on the Performance of the Irreversible Dual-Miller Cycle
},
  journal = {International Journal of Fluid Mechanics & Thermal Sciences},
  volume = {11},
  number = {3},
  pages = {33-49},
  doi = {10.11648/j.ijfmts.20251103.11},
  url = {https://doi.org/10.11648/j.ijfmts.20251103.11},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijfmts.20251103.11},
  abstract = {Since the effects of various irreversible losses and cycle conditions on the internal combustion engine performance are significant, it is important to compare the effects of the parameters on the performance in a cycle study. Thermodynamic cycle studies should take into account the irreversible losses such as internal irreversibility, friction losses, heat transfer losses, and the variation of the specific heat of the working fluid. This study aims at deriving the analytic equation with respect to ecological function of the irreversible Dual-Miller cycle (DMC) by using the specific heat model of polynomial, and comparing results of performance calculation of different friction losses, and analyzing the effect of the cycle parameters for optimum performance. The calculation results show that the friction loss has a considerable influence on the engine performance, but there is no significant difference in the choice of the cycle parameters for optimum performance. It is also found that optimizing the ecological function is an effective way to simultaneously increase the power and efficiency, and the friction loss is not affected. The cut-off ratio, which gives the ecological function maximum, is between the cut-off ratio, which gives the power and efficiency maximum, and the Miller cycle ratio, respectively, which is closer to the efficiency maximum. The Miller cycle ratio that maximizes performance is slightly larger than the cut-off ratio. The presented models and results are expected to provide guidelines for the design and optimization of DMC engines, and for the performance improvement and to perform the cycle modeling close to the cycle of the actual engine.},
 year = {2025}
}

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TY  - JOUR
T1  - Effects of Friction Loss Models and Cycle Parameters on the Performance of the Irreversible Dual-Miller Cycle

AU  - Kum Song Choe
AU  - Yong Jae Min
AU  - Sang Dok Ri
AU  - Myong Chol Ri
Y1  - 2025/08/25
PY  - 2025
N1  - https://doi.org/10.11648/j.ijfmts.20251103.11
DO  - 10.11648/j.ijfmts.20251103.11
T2  - International Journal of Fluid Mechanics & Thermal Sciences
JF  - International Journal of Fluid Mechanics & Thermal Sciences
JO  - International Journal of Fluid Mechanics & Thermal Sciences
SP  - 33
EP  - 49
PB  - Science Publishing Group
SN  - 2469-8113
UR  - https://doi.org/10.11648/j.ijfmts.20251103.11
AB  - Since the effects of various irreversible losses and cycle conditions on the internal combustion engine performance are significant, it is important to compare the effects of the parameters on the performance in a cycle study. Thermodynamic cycle studies should take into account the irreversible losses such as internal irreversibility, friction losses, heat transfer losses, and the variation of the specific heat of the working fluid. This study aims at deriving the analytic equation with respect to ecological function of the irreversible Dual-Miller cycle (DMC) by using the specific heat model of polynomial, and comparing results of performance calculation of different friction losses, and analyzing the effect of the cycle parameters for optimum performance. The calculation results show that the friction loss has a considerable influence on the engine performance, but there is no significant difference in the choice of the cycle parameters for optimum performance. It is also found that optimizing the ecological function is an effective way to simultaneously increase the power and efficiency, and the friction loss is not affected. The cut-off ratio, which gives the ecological function maximum, is between the cut-off ratio, which gives the power and efficiency maximum, and the Miller cycle ratio, respectively, which is closer to the efficiency maximum. The Miller cycle ratio that maximizes performance is slightly larger than the cut-off ratio. The presented models and results are expected to provide guidelines for the design and optimization of DMC engines, and for the performance improvement and to perform the cycle modeling close to the cycle of the actual engine.
VL  - 11
IS  - 3
ER  -

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Author Information

Kum Song Choe

Faculty of Physical Engineering, Kim Chaek University of Technology, Pyongyang, DPR Korea
Yong Jae Min

Faculty of Physical Engineering, Kim Chaek University of Technology, Pyongyang, DPR Korea

Contact Email

http://orcid.org/0009-0009-9747-5099
Sang Dok Ri

Faculty of Physical Engineering, Kim Chaek University of Technology, Pyongyang, DPR Korea
Myong Chol Ri

Faculty of Physical Engineering, Kim Chaek University of Technology, Pyongyang, DPR Korea

http://orcid.org/0009-0007-2328-1588

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APA Style

Choe, K. S., Min, Y. J., Ri, S. D., Ri, M. C. (2025). Effects of Friction Loss Models and Cycle Parameters on the Performance of the Irreversible Dual-Miller Cycle. International Journal of Fluid Mechanics & Thermal Sciences, 11(3), 33-49. https://doi.org/10.11648/j.ijfmts.20251103.11

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ACS Style

Choe, K. S.; Min, Y. J.; Ri, S. D.; Ri, M. C. Effects of Friction Loss Models and Cycle Parameters on the Performance of the Irreversible Dual-Miller Cycle. Int. J. Fluid Mech. Therm. Sci. 2025, 11(3), 33-49. doi: 10.11648/j.ijfmts.20251103.11

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AMA Style

Choe KS, Min YJ, Ri SD, Ri MC. Effects of Friction Loss Models and Cycle Parameters on the Performance of the Irreversible Dual-Miller Cycle. Int J Fluid Mech Therm Sci. 2025;11(3):33-49. doi: 10.11648/j.ijfmts.20251103.11

Copy | Download

@article{10.11648/j.ijfmts.20251103.11,
  author = {Kum Song Choe and Yong Jae Min and Sang Dok Ri and Myong Chol Ri},
  title = {Effects of Friction Loss Models and Cycle Parameters on the Performance of the Irreversible Dual-Miller Cycle
},
  journal = {International Journal of Fluid Mechanics & Thermal Sciences},
  volume = {11},
  number = {3},
  pages = {33-49},
  doi = {10.11648/j.ijfmts.20251103.11},
  url = {https://doi.org/10.11648/j.ijfmts.20251103.11},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijfmts.20251103.11},
  abstract = {Since the effects of various irreversible losses and cycle conditions on the internal combustion engine performance are significant, it is important to compare the effects of the parameters on the performance in a cycle study. Thermodynamic cycle studies should take into account the irreversible losses such as internal irreversibility, friction losses, heat transfer losses, and the variation of the specific heat of the working fluid. This study aims at deriving the analytic equation with respect to ecological function of the irreversible Dual-Miller cycle (DMC) by using the specific heat model of polynomial, and comparing results of performance calculation of different friction losses, and analyzing the effect of the cycle parameters for optimum performance. The calculation results show that the friction loss has a considerable influence on the engine performance, but there is no significant difference in the choice of the cycle parameters for optimum performance. It is also found that optimizing the ecological function is an effective way to simultaneously increase the power and efficiency, and the friction loss is not affected. The cut-off ratio, which gives the ecological function maximum, is between the cut-off ratio, which gives the power and efficiency maximum, and the Miller cycle ratio, respectively, which is closer to the efficiency maximum. The Miller cycle ratio that maximizes performance is slightly larger than the cut-off ratio. The presented models and results are expected to provide guidelines for the design and optimization of DMC engines, and for the performance improvement and to perform the cycle modeling close to the cycle of the actual engine.},
 year = {2025}
}

Copy | Download

TY  - JOUR
T1  - Effects of Friction Loss Models and Cycle Parameters on the Performance of the Irreversible Dual-Miller Cycle

AU  - Kum Song Choe
AU  - Yong Jae Min
AU  - Sang Dok Ri
AU  - Myong Chol Ri
Y1  - 2025/08/25
PY  - 2025
N1  - https://doi.org/10.11648/j.ijfmts.20251103.11
DO  - 10.11648/j.ijfmts.20251103.11
T2  - International Journal of Fluid Mechanics & Thermal Sciences
JF  - International Journal of Fluid Mechanics & Thermal Sciences
JO  - International Journal of Fluid Mechanics & Thermal Sciences
SP  - 33
EP  - 49
PB  - Science Publishing Group
SN  - 2469-8113
UR  - https://doi.org/10.11648/j.ijfmts.20251103.11
AB  - Since the effects of various irreversible losses and cycle conditions on the internal combustion engine performance are significant, it is important to compare the effects of the parameters on the performance in a cycle study. Thermodynamic cycle studies should take into account the irreversible losses such as internal irreversibility, friction losses, heat transfer losses, and the variation of the specific heat of the working fluid. This study aims at deriving the analytic equation with respect to ecological function of the irreversible Dual-Miller cycle (DMC) by using the specific heat model of polynomial, and comparing results of performance calculation of different friction losses, and analyzing the effect of the cycle parameters for optimum performance. The calculation results show that the friction loss has a considerable influence on the engine performance, but there is no significant difference in the choice of the cycle parameters for optimum performance. It is also found that optimizing the ecological function is an effective way to simultaneously increase the power and efficiency, and the friction loss is not affected. The cut-off ratio, which gives the ecological function maximum, is between the cut-off ratio, which gives the power and efficiency maximum, and the Miller cycle ratio, respectively, which is closer to the efficiency maximum. The Miller cycle ratio that maximizes performance is slightly larger than the cut-off ratio. The presented models and results are expected to provide guidelines for the design and optimization of DMC engines, and for the performance improvement and to perform the cycle modeling close to the cycle of the actual engine.
VL  - 11
IS  - 3
ER  -

Copy | Download