Scavenging is becoming one of the determinants of two-stroke engine performance. Efficiency of U-type loop scavenging of two-stroke diesel engine with two poppet valves is generally unsatisfactory due to scavenging short-circuiting and large amount of residual burned gas in cylinder, and it is hard to generate the swirl that facilitates fuel spray mixing and combustion. In order to deal with the above issues, a swirl-loop scavenging configuration is proposed to involve swirl and depress short-circuiting. To investigate swirl-loop scavenging performance, this article simulates the scavenging process by numerical method, optimizes the tracer gas method to measure and evaluate the scavenging performance, as well as analyzes the influence factors. The results demonstrate that, compared with U-type loop scavenging, the trapping efficiency and scavenging efficiency of swirl-loop scavenging respectively increase by 8% and 10%. Change of engine speed has an impact on the delivery ratio and trapping efficiency but load does not. Both intake and exhaust valve timings affect scavenging performance and short-circuiting to a large extent. In addition, the accuracy of tracer gas method in measurement of scavenging performance parameters is improved, and the scavenging efficiency deviation between simulation and experiment is decreased from 6% to 2%.
MattarelliE.Virtual design of a novel two-stroke high-speed direct-injection diesel engine. Int J Eng Res2009; 10(3): 175–193.
2.
Liz HeBQZhaoH.Influences of intake ports and pent-roof structures on the flow characteristics of a poppet-valved two-stroke gasoline engine. Int J Eng Res2016; 17(10): 1077–1091.
3.
Dalla NoraM. Experimental and numerical study of a two-stroke poppet valve engine fuelled with gasoline and ethanol. Doctoral Dissertation, Brunel University London, Uxbridge, 2016.
4.
StokesJHundlebyGELakeTHChristieM.Development experience of a poppet-valved two-stroke flagship engine. SAE technical paper 920778, 1992.
5.
LuYPeiPLiuY.An evaluation of a 2/4-stroke switchable secondary expansion internal combustion engine. Appl Therm Eng2014; 73(1): 325–334.
6.
Dalla NoraMZhaoH. High load performance and combustion analysis of a four-valve direct injection gasoline engine running in the two-stroke cycle. Appl Energ2015; 159: 117–131.
7.
WangXMaJZhaoH.Analysis of mixture formation process in a two-stroke boosted uniflow scavenged direct injection gasoline engine. Int J Eng Res2018; 19(9): 927–940.
8.
BenajesJNovellaRLimaDDJTribottePQuechonNObernesserP, et al. Analysis of the combustion process, pollutant emissions and efficiency of an innovative 2-stroke HSDI engine designed for automotive applications. Appl Therm Eng2013; 58(1–2): 181–193.
9.
YuanCRenHXuJ.Comparison of the gas exchange of a loop scavenged free-piston engine alternator and the conventional engine. Appl Therm Eng2017; 127: 638–649.
10.
MaFZhaoCZhangFZhaoZZhangS.Effects of scavenging system configuration on in-cylinder air flow organization of an opposed-piston two-stroke engine. Energies2015; 8(8): 5866–5884.
11.
Dalla NoraMLanzanovaTDMZhaoH. Investigation of performance and combustion characteristics of a four-valve supercharged two-stroke DI engine fuelled with gasoline and ethanol. Fuel2018; 227: 401–411.
12.
ZhangYZhaoH.Measurement of short-circuiting and its effect on the controlled autoignition or homogeneous charge compression ignition combustion in a two-stroke poppet valve engine. Proc IMechE, Part D: J Automobile Engineering2012; 226(8): 1110–1118.
13.
ZhangYZhaoH.Optimisation of boosting strategy for controlled auto-ignition combustion in a four-valve camless gasoline direct injection engine running in two-stroke cycle. Int J Eng Res2014; 1507: 850–861.
14.
JiFBaoYZhouYDuFZhuHZhaoS, et al. Investigation on performance and implementation of tesla turbine in engine waste heat recovery. Energ Convers Manag2019; 179: 326–338.
15.
TrbottePRavetFDugueVObernesserPQuechonN.Two strokes diesel engine-promising solution to reduce CO2 emissions. Proc Soc Behav Sci2012; 48(9): 2295–2314.
16.
Dalla NoraMZhaoH. Effects of valve timing, valve lift and exhaust backpressure on performance and gas exchanging of a two-stroke GDI engine with overhead valves. Energ Convers Manag2016; 123: 71–83.
17.
NakanoMSatoKUkawaH.A two-stroke cycle gasoline engine with poppet valves on the cylinder head. SAE technical paper 901664, 1990.
18.
NomuraK.Development of a new two stroke engine with poppet-valves: Toyota S-2 Engine. New Gener Two-Stroke Engine1993; 11: 29–30.
19.
BenajesJNovellaRDe LimaDTribotteP.Analysis of combustion concepts in a newly designed two-stroke high-speed direct injection compression ignition engine. Int J Engine Res2015; 16(1): 52–67.
20.
SatoKUkawaHNakanoM. A two-stroke cycle gasoline engine with poppet valves in the cylinder head—part II. SAE technical paper 920780, 1992. DOI: https://doi.org/10.4271/920780
21.
UkawaHNakanoMSatoK. A two-stroke cycle gasoline engine with poppet valves in the cylinder head—part III: an application of gaseous fuel direct injection system. SAE technical paper 930983, 1993. DOI: https://doi.org/10.4271/930983
22.
YangXOkajimaATakamotoYObokataT.Numerical study of scavenging flow in poppet-valved two-stroke engines. Int Congress Expos1999; 12: 38–47.
23.
StokesJHundlebyGELakeTHChristieM.Development experience of a poppet-valved two-stroke flagship engine. SAE technical paper 920778, 1992.
24.
HeBXiaoL.Effects of intake pressure and injection on the combustion characteristics of a poppet-valve two-stroke direct injection gasoline engine in lean conditions. J Combust Sci Technol2018; 24(2): 111–119.
25.
ZahidiMKHanipahMRRamasamyDNoorMMKadirgamaKRahmanM.The two-stroke poppet valve engine. Part 1: intake and exhaust ports flow experimental assessments. IOP Conf Ser: Mater Sci Eng2017; 257(1): 012–023.
26.
ZahidiMKHanipahMR.The two-stroke poppet valve engine. Part 2: numerical investigations of intake and exhaust flow behavior. IOP Conf Ser: Mater Sci Eng2017; 257(1): 12–24.
27.
LinHYLongXY.Simulation study of an aero-piston engine with single stage turbocharger. J Aerosp Power2009; 10: 13–32.
28.
HaiderSSchnipperTObeidatAMeyerKEOkulovVLMayerS, et al. PIV study of the effect of piston position on the in-cylinder swirling flow during the scavenging process in large two-stroke marine diesel engines. J Marine Sci Tech2013; 18(1): 133–143.
29.
ObeidatASchnipperTIngvorsenKMHaiderSMeyerKEMayerS, et al. Large eddy simulations of the influence of piston position on the swirling flow in a model two-stroke diesel engine. Int J Num Method Heat Fluid Flow2014; 24(2): 325–341.
30.
AndersenFHHultJNogenmyrKJMayerS. CFD analysis of the scavenging process in marine two-stroke diesel engines. In: Proceedings of the ASME internal combustion engine division fall technical conference, Columbus, IN, 19–22 October 2014, pp.87–95. New York: ASME.
31.
HemmingsenCSIngvorsenKMMayerSWaltherJH.LES and URANS simulations of the swirling flow in a dynamic model of a uniflow-scavenged cylinder. Int J Heat Fluid Flow2016: 62: 213–223.
32.
IngvorsenKMMeyerKEWaltherJHMayerS.Turbulent swirling flow in a dynamic model of a uniflow-scavenged two-stroke engine. Experim Fluid2014; 55(6): 17–48.
33.
WuD.Investigation on the gas exchange of an opposed-piston two-stroke diesel engine. Master Dissertation, Beijing Institute of Technology, Beijing, China, 2015.
34.
OliverPJ.A numerical investigation of the scavenging flow in a two-stroke engine with passive intake valves. Doctoral Dissertation, Queen’s University, Kingston, ON, Canada, 2008.
35.
CaoKDingSTDuFRWangZY.Effects of porting arrangements on intake swirl and scavenging performance. J Aerospace Power2013; 28(8): 1711–1718.
36.
McTaggart-CowanGPBusheWKHillPGMunshiSR. A supercharged heavy-duty diesel single-cylinder research engine for high-pressure direct injection of natural gas. Int J Eng Res2003; 4(4): 315–330.
37.
DuFRJiangB.The influence of ports parameters on scavenging properties of two-stroke HFE. Sci Technol Eng2011; 11(3): 538–532.
38.
DongX.Research on scavenging process and turbocharging matching of an opposed-piston two-stroke diesel engine. Doctoral dissertation, Beijing Institute of Technology, Beijing, China, 2015.
39.
QiuZDShenJ.Helical inlet port test and evaluation method for direct injection diesel engine. Chin Int Combust Engine Eng2005; 26(3): 27–30.
40.
CaoJK.Investigation of the mechanisms and the system sensitivity analysis methods for scavenging swirls in aircraft heavy fuel engines. Doctoral Dissertation, Beihang University, Beijing, China, 2014.
41.
MaFZhaoCZhangFZhaoZZhangSStewartP, et al. Effects of scavenging system configuration onin-cylinder air flow organization of apposed-piston two-stroke engine. Energies2015(8): 5866–5884.
42.
McgoughMGPanickER. Experimental investigation of the scavenging performance of a two-stroke opposed-piston diesel tank engine. SAE technical paper 2004-01-1591, 2004.
43.
BakshiSAnandTNCRavikrishnaRV. In-cylinder charge stratification and fuel-air mixing in a new, lowemission two-stroke engine. Int J Eng Res2007; 8(3): 271–287.
44.
ZhouYShaoLTZhangCJiFLiuJLiG, et al. Numerical and experimental investigation on dynamic performance of bump foil journal bearing based on journal orbit. Chinese J Aeronaut2021; 34. DOI: https://doi.org/10.1016/j.cja.2019.12.001
45.
WangXYMaJZhaoH. Analysis of scavenge port designs and exhaust valve profiles on the in-cylinder flow and scavenging performance in a two-stroke boosted uniflow scavenged direct injection gasoline engine. Int J Eng Res2018; 19(5): 509–527.
46.
AdairJOlsenDKirkpatrickA. Exhaust tuning of large-bore, multicylinder, two-stroke, natural gas engines. Int J Eng Res2006; 7(2): 131–141.
