Improving incomplete combustion and reducing engine-out emissions in reactivity controlled compression ignition engine fueled by ethanol

  • H. R. FajriEmail author
  • M. Mohebi
  • H. Adibi-Asl
  • A. Abdul Aziz
  • S. A. Jazayeri
Original Paper


In this paper, various fuels with different reactivities were implemented as a strategy to optimize the heat release rate which could be a dominant combustion controller in an internal combustion engine. Using a blend of ethanol and gasoline fuels is one of the best approaches to decrease heat release rate, as well as prolonging combustion duration and retarding combustion phasing. Application of ethanol fuel, however, may lead to misfire and unstable combustion in reactivity controlled compression ignition engines. A multi-dimensional model coupled with a detailed chemical kinetic mechanism was applied to investigate the effects of single and double injections within misfire zones in a research engine using iso-octane, n-heptane, and ethanol fuels. A parametric approach is employed to analyze the engine model behavior through varying energy fraction of fuels through both single and double injections strategies. Three performance maps of engine at varying total fuel energy with different ratios of the port to direct fuel injections have been simulated. The first map is related to using net iso-octane and n-heptane fuels; the other two maps are related to the use of 20% and 40% ethanol fuels instead of net iso-octane fuel, respectively. The results highlight that double injection strategy with the injection timing between 27° and 47° before top dead center is capable of improving misfire points also effective on reducing both nitrogen oxide formation and ringing intensity, as well as improving engine gross indicated efficiency.


Misfire Injection timing Nitrogen oxide emission Unburned fuel 



After top dead center


Brake specific fuel consumption


Before top dead center


Crank angle


The location of 10% MFB


The location of 50% MFB


The location of 90% MFB


Computational fluid dynamic


Carbon monoxide


Carbon dioxide


Exhaust gas recirculation


Environmental protection agency


Engine research center


20% Ethanol fuel by energy


40% Ethanol fuel by energy


Gross indicated efficiency


Homogeneous charge compression ignition


Lower heating value


Low-temperature combustion


Mean effective pressure


Mass fraction burned


Nitrogen oxides


Premixed charge compression ignition


Particulate matters


Pressure rise rate


Reactivity controlled compression ignition


Ringing intensity


Start of injection


Top dead center


Unburned hydrocarbon



Adjustable parameter


Adjustable parameter

\(c_{\varepsilon 1} , c_{\varepsilon 2} ,c_{\varepsilon 3}\)

RANS model constants


Mass diffusivity of liquid vapor in air


Sac diameter


Parent parcel diameter


Diameter of the smaller droplet


Turbulent kinetic energy


Ratio of the nozzle length to the nozzle diameter


Mass of species m in the cell


Total mass in the cell

\(P_{\rm{max} }\)

Peak pressure


Prandtl number


Ideal gas constant


Drop radius


Sherwood number


Source term (in transport equations)

\(T_{\rm{max} }\)

Peak temperature


Vapor mass fraction at the drop’s surface


Vapor mass fraction


Calculated frequency


Calculated wavelength


Collision angle


Specific heat ratio


Dissipation of turbulent kinetic energy


Turbulent viscosity


Air density


Liquid density


Density of species m in the cell


Total density in the cell


Surface tension


Stress tensor


Transported quantity

\(\varGamma_{\phi }\)

Diffusion coefficient



This study has used the experimental data of a single-cylinder Cat® 3401E SCOTE engine for simulation validation, accordingly, the authors acknowledge ERC of the University of Wisconsin–Madison for this information.


  1. Amsden AA, O’rourke P, Butler T (1989) KIVA-II: a computer program for chemically reactive flows with sprays. Los Alamos National Lab, Los AlamosGoogle Scholar
  2. Baumgarten C (2006) Mixture formation in internal combustion engines. Springer, BerlinGoogle Scholar
  3. Benajes J, Pastor JV, García A, Monsalve-Serrano J (2015) The potential of RCCI concept to meet EURO VI NOx limitation and ultra-low soot emissions in a heavy-duty engine over the whole engine map. Fuel 159:952–961. CrossRefGoogle Scholar
  4. Curran S, Hanson R, Wagner R (2012) Effect of E85 on RCCI performance and emissions on a multi-cylinder light-duty diesel engine. SAE Technical Paper 2012-01-0376.
  5. Curran S, Hanson R, Wagner R, Reitz RD (2013) Efficiency and emissions mapping of RCCI in a light-duty diesel engine. SAE Technical Paper 2013-01-0289.
  6. Curran S, Gao Z, Wagner R (2014) Reactivity controlled compression ignition drive cycle emissions and fuel economy estimations using vehicle systems simulations with E30 and ULSD. SAE Int J Eng 7:902–912. CrossRefGoogle Scholar
  7. Dec JE (2009) Advanced compression-ignition engines—understanding the in-cylinder processes. Proc Combust Inst 32:2727–2742. CrossRefGoogle Scholar
  8. Dec JE, Yang Y (2010) Boosted HCCI for high power without engine knock and with ultra-low NOx emissions-using conventional gasoline. SAE Int J Eng 3:750–767. CrossRefGoogle Scholar
  9. DelVescovo D, Wang H, Wissink M, Reitz RD (2015) Isobutanol as both low reactivity and high reactivity fuels with addition of di-tert butyl peroxide (DTBP) in RCCI combustion. SAE Int J Fuels Lubr 8(2):329–343. CrossRefGoogle Scholar
  10. DelVescovo D, Kokjohn S, Reitz R (2017) The effects of charge preparation, fuel stratification, and premixed fuel chemistry on reactivity controlled compression ignition (RCCI) combustion. SAE Int J Eng 10(4):1491–1505. CrossRefGoogle Scholar
  11. Dempsey AB (2013) Dual-fuel reactivity controlled compression ignition (RCCI) with alternative fuels. Doctoral dissertation, The University of Wisconsin-MadisonGoogle Scholar
  12. Dempsey AB, Adhikary BD, Viswanathan S, Reitz RD (2012) Reactivity controlled compression ignition using premixed hydrated ethanol and direct injection diesel. J Eng Gas Turbines Power 134:082806. CrossRefGoogle Scholar
  13. Eng J (2002) Characterization of pressure waves in HCCI combustion. SAE Technical Paper 2002-01-2859.
  14. Fajri HR, Jafari MJ, Shamekhi AH, Jazayeri SA (2017) A numerical investigation of the effects of combustion parameters on the performance of a compression ignition engine toward NOx emission reduction. J Clean Prod 167:140–153. CrossRefGoogle Scholar
  15. Fajri HR, Shamekhi AH, Rezaie S, Jafari MJ, Jazayeri SA (2019) A detailed study of boost pressure and injection timing on an RCCI Engine map fueled with Iso-Octane and n-heptane Fuels. J Appl Fluid Mech 12:1161–1175. CrossRefGoogle Scholar
  16. Gonzalez DMA, Lian ZW, Reitz RD (1992) Modeling diesel engine spray vaporization and combustion. SAE transactions, pp 1064–1076.
  17. Guerrero J (2014) Introduction to computational fluid dynamics: governing equations, turbulence modeling introduction and finite volume discretization basics. State key laboratory of advanced design and manufacturing for vehicle body. Dicat.Unige.It. (n.d.). 
  18. Hardy WL, Reitz RD (2006) A study of the effects of high EGR, high equivalence ratio, and mixing time on emissions levels in a heavy-duty diesel engine for PCCI combustion. SAE Technical Paper 2006-01-0026.
  19. Hashizume T, Miyamoto T, Hisashi A, Tsujimura K (1998) Combustion and emission characteristics of multiple stage diesel combustion. SAE Technical Paper 980505.
  20. Hiroyasu, H., Arai, M., (1990) Structures of fuel sprays in diesel engines. SAE Technical Paper 900475.
  21. Hiroyasu H, Kadota T (1976) Models for combustion and formation of nitric oxide and soot in direct injection diesel engines. SAE Technical Paper 760129.
  22. Kokjohn SL, Hanson RM, Splitter DA, Reitz RD (2009) Experiments and modeling of dual-fuel HCCI and PCCI combustion using in-cylinder fuel blending. SAE Tech Pap 2(2):24–39. CrossRefGoogle Scholar
  23. Kokjohn S, Hanson R, Splitter D, Kaddatz J, Reitz RD (2011a) Fuel reactivity controlled compression ignition (RCCI) combustion in light-and heavy-duty engines. SAE Int J Eng 4:360–374. CrossRefGoogle Scholar
  24. Kokjohn S, Hanson R, Splitter D, Reitz R (2011b) Fuel reactivity controlled compression ignition (RCCI): a pathway to controlled high-efficiency clean combustion. Int J Eng Res 12:209–226. CrossRefGoogle Scholar
  25. Ladommatos N, Abdelhalim SM, Zhao H, Hu Z (1998) Effects of EGR on heat release in diesel combustion. SAE Technical Paper 980184.
  26. Ma S, Zheng Z, Liu H, Zhang Q, Yao M (2013) Experimental investigation of the effects of diesel injection strategy on gasoline/diesel dual-fuel combustion. Appl Energy 109:202–212. CrossRefGoogle Scholar
  27. Moukalled F, Mangani L, Darwish M (2016) The finite volume method in computational fluid dynamics. In: Thess A, Moreau R (eds) An advanced introduction with OpenFOAM and Matlab. Springer, SwitzerlandGoogle Scholar
  28. Naber J, Reitz RD (1988) Modeling engine spray/wall impingement. SAE Technical Paper 880107.
  29. Nazemi M, Shahbakhti M (2016) Modeling and analysis of fuel injection parameters for combustion and performance of an RCCI engine. Appl Energy 165:135–150. CrossRefGoogle Scholar
  30. O’Rourke PJ (1981) Collective drop effects on vaporizing liquid sprays. Los Alamos National Lab, Los AlamosGoogle Scholar
  31. O’Rourke PJ, Amsden AA (1987) The TAB method for numerical calculation of spray droplet breakup. Los Alamos National Lab, Los AlamosGoogle Scholar
  32. Qian Y, Wang X, Zhu L, Lu X (2015) Experimental studies on combustion and emissions of RCCI (reactivity controlled compression ignition) with gasoline/n-heptane and ethanol/n-heptane as fuels. Energy 88:584–594. CrossRefGoogle Scholar
  33. Ra Y, Reitz RD (2011) A combustion model for IC engine combustion simulations with multi-component fuels. Combust Flame 158:69–90. CrossRefGoogle Scholar
  34. Ra Y, Yun JE, Reitz RD (2009) Numerical simulation of gasoline-fuelled compression ignition combustion with late direct injection. Int J Veh Des 50:3–34. CrossRefGoogle Scholar
  35. Reitz R (1987) Modeling atomization processes in high-pressure vaporizing sprays. Atomisation Spray Technol 3(4):309–337Google Scholar
  36. Reitz R, Bracco F (1986) Mechanisms of breakup of round liquid jets. Encycl Fluid Mech 3:233–249Google Scholar
  37. Richards K, Senecal P, Pomraning E (2014) CONVERGE (Version 2.2. 0) Manual, Convergent Science. Inc., Madison.
  38. Schmidt DP, Rutland C (2000) A new droplet collision algorithm. J Comput Phys 164:62–80. CrossRefGoogle Scholar
  39. Senecal P, Pomraning E, Richards K, Briggs T, Choi C, McDavid R, Patterson M (2003) Multi-dimensional modeling of direct-injection diesel spray liquid length and flame lift-off length using CFD and parallel detailed chemistry. SAE Technical Paper 2003-01-1043.
  40. Shundoh S, Komori M, Tsujimura K, Kobayashi S, (1992) NOx reduction from diesel combustion using pilot injection with high pressure fuel injection. SAE Technical Paper 920461.
  41. Smith GP, Golden DM, Frenklach M, Moriarty NW, Eiteneer B, Goldenberg M, Bowman C, Hanson RK, Song S, Gardiner JWC (1999) GRI-Mech version 3.0Google Scholar
  42. Splitter DA (2010) Experimental investigation of fuel reactivity controlled combustion in a heavy-duty internal combustion engine. M.S. thesis - University of Wisconsin–MadisonGoogle Scholar
  43. Splitter D, Kokjohn S, Rein K, Hanson R, Sanders S, Reitz RD (2010) An optical investigation of ignition processes in fuel reactivity controlled PCCI combustion. SAE Int J Eng 3(1):142–162. CrossRefGoogle Scholar
  44. Splitter D, Hanson R, Kokjohn S, Reitz RD (2011a) Reactivity controlled compression ignition (RCCI) heavy-duty engine operation at mid-and high-loads with conventional and alternative fuels. SAE Technical Paper 2011-01-0363.
  45. Splitter DA, Hanson RM, Reitz RD, Manente V, Johansson B (2011b) Modeling charge preparation and combustion in diesel fuel, ethanol, and dual-fuel PCCI engines. Atomization Sprays. CrossRefGoogle Scholar
  46. Stiesch G (2013) Modeling engine spray and combustion processes. Springer, BerlinGoogle Scholar
  47. Sun Y (2007) Diesel combustion optimization and emissions reduction using adaptive injection strategies (AIS) with improved numerical models. ProQuestGoogle Scholar
  48. Tong L, Wang H, Zheng Z, Reitz R, Yao M (2016) Experimental study of RCCI combustion and load extension in a compression ignition engine fueled with gasoline and PODE. Fuel 181:878–886. CrossRefGoogle Scholar
  49. Uchida N, Daisho Y, Saito T, Sugano H (1993) Combined effects of EGR and supercharging on diesel combustion and emissions. SAE Technical Paper 930601.
  50. Zheng M, Han X, Asad U, Wang J (2015) Investigation of butanol-fuelled HCCI combustion on a high efficiency diesel engine. Energy Convers Manag 98:215–224. CrossRefGoogle Scholar

Copyright information

© Islamic Azad University (IAU) 2019

Authors and Affiliations

  1. 1.Iran Khodro Powertrain CompanyTehranIran
  2. 2.Department of Mechanical EngineeringUniversity of Technology, MalaysiaJohor BahruMalaysia
  3. 3.Department of Mechanical EngineeringUniversity of WaterlooWaterlooCanada
  4. 4.Department of Mechanical EngineeringK. N. Toosi University of TechnologyTehranIran

Personalised recommendations