Restricted accessResearch articleFirst published online 2026-2
Numerical simulation of the effect of combustion characteristics in a high-compression-ratio lean-burn gasoline engine utilizing a two-stage water injection strategy
High compression ratios and lean burning were recognized as effective strategies to enhance the thermal efficiency of engines. However, knocking phenomena often impose constraints on further efficiency improvements in engines with high compression ratios. In this paper, computational fluid dynamics (CFD) was employed to simulate the combustion characteristics of an ultra-high compression ratio (CR = 17) gasoline engine with an Atkinson cycle. Meanwhile, single and two-stage water injection strategies were proposed to address the knocking of lean burn engines. Knocking could apparently be suppressed by direct water injection; specifically, the two-stage water injection strategy depicted a better cooling influence caused by evenly distributed water vapor. The two-stage injection strategy resulted in a 105 K reduction in cylinder temperature compared to no water injection. Moreover, this strategy effectively mitigates the deleterious effects of water injection on the initial flame kernel formation and flame propagation, thereby reducing ignition delay time and duration of combustion. Notably, the water injection efficiency of the two-stage water injection strategy is about four times higher than that of the single water injection strategy.
ZhangQPeiYAnY, et al. Study of water direct injection on knock control and combustion process of a high compression ratio GDI engine. Fuel2021; 306: 121631.
2.
LiuZZhengZZhangZLiM.The effect of direct water injection on the combustion stability of a downsized boost engine under high compression ratios and load conditions. Fuel2022; 308: 121945.
3.
LiuZZhangZRaoSZhengZ.Study of water injection on suppressing knock in a high compression ratio and supercharged hybrid gasoline engine. Energy2024; 287: 129702.
4.
BorettiA.Water injection strategies to control gas temperatures in hydrogen–air internal combustion engines. J Braz Soc Mech Sci Eng2024; 46(1): 54.
5.
LiuZZhengZ.The effect of ignition energy on the lean combustion limitation in high compression ratio engines. Energy2024; 301: 131591.
ZhouFFuJKeWLiuJYuanZLuoB.Effects of lean combustion coupling with intake tumble on economy and emission performance of gasoline engine. Energy2017; 133: 366–379.
8.
ZhouYHongWYangYLiXXieFSuY.Experimental investigation of diluents components on performance and emissions of a high compression ratio methanol SI engine. Energies2019; 12(17): 3366.
9.
IbrahimABariS.Effect of varying compression ratio on a natural gas SI engine performance in the presence of EGR. Energy Fuels2009; 23(10): 4949–4956.
10.
XiaCZhaoTFangJZhuLHuangZ.Experimental study of stratified lean burn characteristics on a dual injection gasoline engine. Front Energy2022; 16(6): 900–915.
11.
LiZQinJPeiYZhongKZhangZSunJ.The lean-burn limit extending experiment on gasoline engine with dual injection strategy and high power ignition system. Energies2023; 16(15): 5662.
12.
LiAZhengZPengT.Effect of water injection timing on the combustion and emissions of a direct injection gasoline engine. Energy Technol2021; 9(7): 1–16.
13.
DaggettDLOrtanderlSEamesDSnyderCBertonJ.Water injection: disruptive technology1 to reduce airplane emissions and maintenance costs. SAE Transactions2004; 113: 1547–1556.
14.
ZembiJBattistoniMRanuzziFCavinaNDe CesareM.CFD analysis of port water injection in a GDI engine under incipient knock conditions. Energies2019; 12(18): 3409.
15.
PostriotiLBriziGFinoriGM.Experimental analysis of water pressure and temperature influence on atomization and evolution of a port water injection spray. Appl Sci2021; 11: 5980–5980.
16.
ZhangZKangZJiangL, et al. Effect of direct water injection during compression stroke on thermal efficiency optimization of common rail diesel engine. S Energy Procedia2017; 142: 1251–1258.
17.
BozzaFDe BellisVTeodosioL.Potentials of cooled EGR and water injection for knock resistance and fuel consumption improvements of gasoline engines. Appl Energy2016; 169: 112–125.
18.
RochaDDDde Castro RadicchiFLopesGS, et al. Study of the water injection control parameters on combustion performance of a spark-ignition engine. Energy2021; 217: 119346.
19.
NetzerCFrankenTSeidelLLehtiniemiHMaussFKulzerAC.Numerical analysis of the impact of water injection on combustion and thermodynamics in a gasoline engine using detailed chemistry. SAE Int J Engines2018; 11(6): 1151–1166.
20.
VaccaABargendeMChiodiM, et al. Analysis of water injection strategies to exploit the thermodynamic effects of water in gasoline engines by means of a 3D-CFD virtual test bench. SAE technical papers 2019-24-0102;2019.
21.
WangJYanFYanD, et al. Effects of water injection on combustion emission and knock characteristics of turbocharged direct injection gasoline engine. Int J Autom Technol2022; 23(4): 899–912.
22.
FanzBRothP.Injection of a H2O2/water solution into the combustion chamber of a direct injection diesel engine and its effect on soot removal. Proc Combust Inst2000; 28(1): 1219–1225.
23.
QinJZhangQPeiYLiXPengZPengZ.Effects of intake manifold water injection mass on combustion and emission characteristics of GDI engine. J Tianjin Univ Sci Technol2020; 53(11): 1167–1174.
24.
RautAAMallikarjunaJM.Effect of in-cylinder air-water interaction on water evaporation and performance characteristics of a direct water injected GDI engine. Eng Sci Technol Int J2021; 24(2): 480–492.
25.
RautAAMallikarjunaJM.Effects of direct water injection and injector configurations on performance and emission characteristics of a gasoline direct injection engine: a computational fluid dynamics analysis. Int J Engine Res2020; 21(8): 1520–1540.
26.
AyhanV.Experimental Investigation of the effect of direct water injection on combustion, knock, and emissions for LPG-diesel dual-fuel engine. J Energy Eng2021; 147(1): 1–12.
27.
IwashiroYTsurushimaTAsaumiYAoyagiY.Fuel consumption improvement and operation range expansion in HCCI with direct water injection. Proc Automob Tech Assoc2002; 33(4): 103–107.
28.
PeiYZhangQPengZ, et al. Thermal efficiency improvement of lean burn high compression ratio engine coupled with water direct injection. Energy Convers Manag2022; 251: 114969.
29.
LiuZZhengZ.Effects of in-cylinder water injection on knocking and combustion stability generated by expanding the lean burn limit. Appl Energy2024; 367: 123324.
30.
LiuZZhengZ.Split injection strategy optimization to achieve ideal stratified-charge mixture and reinforce ultralean burn in a high compression ratio direct injection spark ignition engine. Energy Technol2022; 10(12): 2200751.
31.
WilcoxDC.Formulation of the k-w turbulence model revisited. AIAA J2008; 46: 2823–2838.
32.
DuanXZhangSLiuY, et al. Numerical investigation the effects of the twin-spark plugs coupled with EGR on the combustion process and emissions characteristics in a lean burn natural gas SI engine. Energy2020; 206: 118181.
33.
WeiXQianYMengS, et al. Effects of coupling port water injection and EGR on the spray water evolution, combustion and emission of a premixed stoichiometric natural gas engine: a numerical study. Fuel2022; 324(Part A): 124315.
34.
ColinOBenkenidaAAngelbergerC.3D modeling of mixing, ignition and combustion phenomena in highly stratified gasoline engines. Oil Gas Sci Technol2003; 58(1): 47–62.
35.
GauthierBMDavidsonDFHansonRK.Shock tube determination of ignition delay times in full-blend and surrogate fuel mixtures. Combust Flame2004; 139(4): 300–311.
36.
RautAAMallikarjunaJM.Effect of water injection and spatial distribution on combustion, emission and performance of GDI engine - a CFD analysis (conference paper). SAE technical papers2018.
37.
GonzálezMADReitzRD. Modeling diesel engine spray vaporization and combustion. Intevep SA, Venezuela1991; 813: 291–298.
38.
DouXYosriMTaleiMYangY.Impact of wall heat transfer modelling in large-eddy simulation of hydrogen knocking combustion. Int J Hydrogen Energy2024; 62: 405–417.
39.
RicartLMReltzRDDecJE.Comparisons of diesel spray liquid penetration and vapor fuel distributions with In-cylinder optical measurements. J Eng Gas Turbine Power2000; 122(4): 588–595.
40.
KrastevVSilvestriLFalcucciG.A modified version of the RNG k–ε turbulence model for the scale-resolving simulation of internal combustion engines. Energies2017; 10(12): 2116.
41.
SciortinoDDBonatestaFHopkinsEBellDCaryM.A systematic approach to calibrate spray and break-up models for the simulation of high-pressure fuel injections. Int J Engine Res2023; 24(2): 437–455.
42.
ShangZYuXShiW, et al. Numerical research on effect of hydrogen blending fractions on idling performance of an n-butanol ignition engine with hydrogen direct injection. Fuel2019; 258: 116082.
43.
AmsdenAAButlerTDO’RourkePJ.The KIVA-II computer program for transient multidimensional chemically reactive flows with sprays. SAE Trans1987; 96: 373–383.
44.
ZhenXWangYXuSZhuY.Study of knock in a high compression ratio spark-ignition methanol engine by multi-dimensional simulation. Energy2013; 50(1): 150–159.
45.
KaufMGernMSeefeldtS.Evaluation of water injection strategies for NOx reduction and charge cooling in SI engines. SAE technical papers2019.
