The starting-up process of internal combustion engines presents a great challenge to the tribodynamic performance of the crankshaft-main bearing system. In this study, a transient mixed elastohydrodynamic lubrication model is presented to investigate the transient process. In the model, the average Reynolds equation is adopted with considering the influences of surface deformation and starting temperature. Then the oil film and friction loss of the system and the journal center trajectory during engines starting up are analyzed. The results at different starting temperatures show that the asperity contact under the hot start-up condition is more serious. However, during the engine run-up and transition to idling phases, more viscous friction loss is generated under the cold start-up condition.
TaylorC. Automobile engine tribology – desing consideration for efficiency and durability. Wear1998; 221: 1–8.
2.
BouyerJFillonM. Experimental measurement of the friction torque on hydrodynamic plain journal bearings during start-up. Tribol Int2011; 44: 772–781.
3.
BishopJNedungadiAOstrowskiGet al.An engine start/stop system for improved fuel economy. SAE Technical Paper. 2007-01-17. Epub ahead of print 2007. DOI: 10.4271/2007-01-1777.
4.
FonsecaNCasanovaJValdésM. Influence of the stop/start system on CO2 emissions of a diesel vehicle in urban traffic. Transp Res Part D Transp Environ2011; 16: 194–200.
5.
GreenwoodJATrippJH. The contact of two nominally flat rough surfaces. Proc Inst Mech Eng1970; 185: 625–633.
6.
PatirNChengHS. An average flow model for determining effects of three-dimensional roughness on partial hydrodynamic lubrication. J Lubr Technol1978; 100: 12–17.
7.
PatirNChengHS. Application of average flow model to lubrication between rough sliding surfaces. J Lubr Technol1979; 101: 220–229.
8.
HuY-ZZhuD. A Full numerical solution to the mixed lubrication in point contacts. J Tribol1999; 122: 1–9.
9.
WangYZhangCWangQJet al.A mixed-TEHD analysis and experiment of journal bearings under severe operating conditions. Tribol Int2002; 35: 395–407.
10.
DobricaMBFillonMMaspeyrotP. Mixed elastohydrodynamic lubrication in a partial journal bearing—comparison between deterministic and stochastic models. J Tribol2006; 128: 778–778.
11.
AllmaierHPriestnerCReichFMet al.Predicting friction reliably and accurately in journal bearings – the importance of extensive oil-models. Tribol Int2012; 48: 93–101.
12.
AshiharaKHashimotoH. Theoretical modeling for microgrooved journal bearings under mixed lubrication. J Tribol2010; 132: 42101–42101.
13.
HanYXiongSWangJet al.A new singularity treatment approach for journal-bearing mixed lubrication modeled by the finite difference method with a herringbone mesh. J Tribol2015; 138: 11704–11704.
14.
DadoucheAConlonMJ. Operational performance of textured journal bearings lubricated with a contaminated fluid. Tribol Int2016; 93: 377–389.
15.
HeTZouDLuXet al.Mixed-lubrication analysis of marine stern tube bearing considering bending deformation of stern shaft and cavitation. Tribol Int2014; 73: 108–116.
16.
FillonMBouyerJ. Thermohydrodynamic analysis of a worn plain journal bearing. Tribol Int2004; 37: 129–136.
17.
BartelDBobachLIllnerTet al.Simulating transient wear characteristics of journal bearings subjected to mixed friction. Proc IMechE, Part J: J Engineering Tribology2012; 226: 1095–1108.
18.
SanderDEAllmaierHPriebschHHet al.Edge loading and running-in wear in dynamically loaded journal bearings. Tribol Int2015; 92: 395–403.
19.
SanderDEAllmaierHPriebschHHet al.Simulation of journal bearing friction in severe mixed lubrication – validation and effect of surface smoothing due to running-in. Tribol Int2016; 96: 173–183.
20.
BouyerJFillonMPierre-DanosI. Influence of wear on the behavior of a two-lobe hydrodynamic journal bearing subjected to numerous startups and stops. J Tribol2007; 129: 205–205.
21.
KrithivasanRKhonsariMM. Thermally induced seizure in journal bearings during startup and transient flow disturbance. J Tribol2003; 125: 833–833.
22.
LuXKhonsariMM. On the lift-off speed in journal bearings. Tribol Lett2005; 20: 299–305.
23.
MonmousseauPFillonM. Transient thermoelastohydrodynamic analysis for safe operating conditions of a tilting-pad journal bearing during start-up. Tribol Int2000; 33: 225–231.
24.
Wang X, Zhang Z and Pan J. A Transient thermoelastohydrodynamic analysis of a tilting-pad thrust bearing during start-up. In: World Tribology Congress III, Vol. 2. ASME, 2005, pp.149–150.
25.
WuCZhengL. An average reynolds equation for partial film lubrication with a contact factor. J Tribol1989; 111: 188–188.
26.
SunJGuiC. Effect of lubrication status of bearing on crankshaft strength. J Tribol2007; 129: 887–887.
27.
IllnerTBartelDDetersL. Determination of the transition speed in journal bearings under consideration of bearing deformation. Tribol Int2015; 82: 58–67.
28.
Roelands C. Correlational aspects of the viscosity–temperature pressure relationship of lubricating oils. PhD Thesis, 1966, p.495.
29.
CashJR. Modified extended backward differentiation formulae for the numerical solution of stiff initial value problems in ODEs and DAEs. J Comput Appl Math2000; 125: 117–130.
30.
MengXFangCXieY. Transient tribodynamic model of piston skirt-liner systems with variable speed effects. Tribol Int2016; 94: 640–651.
31.
MengXXieY. Tribology international a new numerical analysis for piston skirt – liner system lubrication considering the effects of connecting rod inertia. Tribiology Int2012; 47: 235–243.
32.
LejsekDKulzerA. Investigations on the transient wall heat transfer at start-up for SI engines with gasoline direct injection. 2009; 2(1): 381–397. DOI: 10.4271/2009-01-0613.
33.
ThomsenKKlitP. A study on compliant layers and its influence on dynamic response of a hydrodynamic journal bearing. Tribol Int2011; 44: 1872–1877.
