Lubrication system calculation with GT-SUITE - Gamma Technologies

GT Suite Conference Frankfurt, 25.10.2010Lubrication system calculation with GT-SUITEPresentation for GAMMA TechnologiesFPT-RACINGCAE Dept.Lamonaca Gianni / Capoferro Ronchetta Giovanni

ContentsContentsPROJECT:Lubrication SystemCalculationGeometry ofsystemOverview :Simulation modelMain features ofthe integratedmodelPROJECT: Lubrication System CalculationGeometry of systemSimulation modelMain features of the Integrated ModelInput DataInput DataOperatingConditionsResultsOperating ConditionsResultsConclusions andfuture workConclusions and future workFrankfurt - October 2010, 25th 2

PROJECT: Lubrication System CalculationContentsPROJECT:Lubrication SystemCalculationGeometry ofsystemOverview :Simulation modelMain features ofthe integratedmodelAIM OF ANALYSIS: 1D CFD for assessment of lubrication system‣Calculate oil flow rates and oil pressure levels for each oil consumer underdifferent engine conditions‣Determination of the required oil pump flow rate and pressure‣Optimization of the lubrication system geometry‣Evaluate effect of cam phaser leakage on oil flow rates and pressure levels‣Examine the operational safety for all engine operation conditions‣Lubrication analysis on bearingsSOFTWARE (version): GT-Suite (v6.2), build 10Input DataOperatingConditionsResultsINPUTGT-SUITEmodelOUTPUTConclusions andfuture workFrankfurt - October 2010, 25th 3

Input data – Geometry of systemContentsPROJECT:Lubrication SystemCalculationGeometry ofsystemOverview :Simulation modelMain features ofthe integratedmodelInput DataOperatingConditionsResultsConclusions andfuture workEngine geometry sectionLubrication systemFrankfurt - October 2010, 25th 4

Overview – Simulation modelContentsPROJECT:Lubrication SystemCalculationEntire modelAnti-drain valveGeometry ofsystemOverview :Simulation modelMain features ofthe integratedmodelCylinder Head and cam phasersInput DataOperatingConditionsResultsConclusions andfuture workCrankcasePumpCranktrain andcounterbalanced shaftsFrankfurt - October 2010, 25th 5

Overview – Simulation base modelContentsPROJECT:Lubrication SystemCalculationGeometry ofsystemCrankcaseMainbearingsPiston cooling jets(modeled with FlowMap)Overview :Simulation modelMain features ofthe integratedmodelOil filterHeatexchangerInput DataOperatingConditionsResultsConclusions andfuture workConrodbearingsOil pumpFrankfurt - October 2010, 25th 6

Overview – Simulation base modelContentsPROJECT:Lubrication SystemCalculationGeometry ofsystemOverview :Simulation modelMain features ofthe integratedmodelInput DataOperatingConditionsResultsCylinder head - exhaust Cylinder head - IntakeTappetsCam PhasersFrom Main GalleryConclusions andfuture workTappets (modeled using an orifice connection element)Camshaft BearingsFrankfurt - October 2010, 25th 7

Overview – Simulation base modelContentsPROJECT:Lubrication SystemCalculationAnti-drain valve (situated between crankcaseand cylinder head)Geometry ofsystemOverview :Simulation basemodelMain features ofthe integratedmodelInput DataModeled withBallPoppetSharpSeattemplateOperatingConditionsResultsConclusions andfuture workFrankfurt - October 2010, 25th 8

Overview – Simulation base modelContentsPROJECT:Lubrication SystemCalculationGeometry ofsystemQuasi-dynamic model of cranktrain and counterbalanced shaftBearing andcounterbalanced shaftOverview :Simulation modelMain features ofthe integratedmodelInput DataOperatingConditionsResultsCrankshaftPistonsConrodsConclusions andfuture workFrankfurt - October 2010, 25th 9

Main features of the integrated modelContentsPROJECT:Lubrication SystemCalculationGeometry ofsystemOverview :Simulation modelMain features ofthe integratedmodelInput DataMain bearings, con-rod bearings, and balance shaft bearings:speed and load calculated from mechanical model of thecranktrain, then imposed directly at bearings in the flowmodelcylinder pressure, piston and conrod mass and inertiaaccounted for in the forcesCamshaft bearing loads calculated using an EXTERNAL GT-SUITE dynamic model of intake and exhaust valvetrainsOperatingConditionsResultsConclusions andfuture workCRANKTRAIN MODEL(mechanical system)• Pump speed• Crankshaft loadsand speed• Counterbalanceshafts loads andspeedHYDRAULIC MODELwithoil pump and bearingsFrankfurt - October 2010, 25th 10

Input data – Consumers characteristics-01 (fluid-dynamic domain)ContentsPROJECT:Lubrication SystemCalculationGeometry ofsystemOil cooler characteristics:modeled with an OrificeConn with calibrated diameter and hole thickness toaccount for friction in the coolercalibrated orifice can be extrapolated to 140°C (not available in theexperiment)Overview :Simulation modelMain features ofthe integratedmodelInput DataOperatingConditionsResultsConclusions andfuture workFrankfurt - October 2010, 25th 11

Input data – Consumers characteristics-02 (fluid-dynamic domain)ContentsPROJECT:Lubrication SystemCalculationGeometry ofsystemOil filter characteristics:modeled with an OrificeConn with calibrated diameter and hole thickness toaccount for friction in the filtercalibrated orifice can be extrapolated to 120°C and 140°C (not available inexperiment)Overview :Simulation modelMain features ofthe integratedmodelInput DataOperatingConditionsResultsConclusions andfuture workFrankfurt - October 2010, 25th 12

Input data-Leakage through tappets (fluid-dynamic domain)ContentsPROJECT:Lubrication SystemCalculationGeometry ofsystemLeakage through tappets (HLAs)Calculated using formula for leakage through a cylindrical guide withAnLeakConn with an external GT-SUITE valvetrain modeloil circuit model uses an OrificeConn with equivalent diameter in order toreduce simulation timeOverview :Simulation modelMain features ofthe integratedmodelFrom cylinder-headInput DataOperatingConditionsResultsConclusions andfuture workCylindricalgroove fortappet feedingFrankfurt - October 2010, 25th 13

Input data – Oil characteristicsContentsPROJECT:Lubrication SystemCalculationGeometry ofsystemOverview :Simulation modelMain features ofthe integratedmodelInput Data10W-60 oil was used with the following characteristics:Characteristics 10W-60Density @ 15°C [kg/m 3 ] 850Density @100°C [kg/m 3 ] 790Kin viscosity @40°C [cSt=mm2/s] 151Kin viscosity @100°C [cSt=mm2/s] 22.8Viscosity vs temperature calculated with Walther equation basedon two kinematic viscosity data points.Density is assumed “quasi-linear” with temperature.OperatingConditions30°CResults50°CConclusions andfuture work140°CFrankfurt - October 2010, 25th 14

Input data – Oil pump mapping (fluid-dynamic domain)ContentsPROJECT:Lubrication SystemCalculationFPT - Gasoline Dept. provided the pump map for 90°C and 120°C90°C 120°CGeometry ofsystemOverview :Simulation modelMain features ofthe integratedmodelInput DataOperatingConditionsResultsConclusions andfuture workThe pump map for 140°C oiltemperature is assumed using asemi-predictive model of thepump140°CFrankfurt - October 2010, 25th15

Input data-Semi-predictive model of oil-pumpContents1D modelization of semi-predictive oil pump and testing circuitPROJECT:Lubrication SystemCalculationGeometry ofsystemOverview :Simulation modelOrifice to simulateimposed pressurelosses downstreamoil pumpOil pump with maps containinglinear characteristics of massflows versus pressure (red lines)Main features ofthe integratedmodelInput DataOperatingConditionsResultsOrifice to simulate relief valveSpring with 30N preloadConclusions andfuture workValve mass in contact withsprings and pressure forcesacting on intake and exhasutside of oil pumpFrankfurt - October 2010, 25th 16

Input data – Anti drain valve (fluid-dynamic domain)ContentsPROJECT:Lubrication SystemCalculationAnti drain valve characteristics: the valve is modeled with asemi predictive modelGeometry ofsystemOverview :Simulation modelMain features ofthe integratedmodelInput DataOperatingConditionsResultsConclusions andfuture workThe pre-compression force of ball valves is imposedequal to 0.21N and the stiffness equal to 0.04N/mmFrankfurt - October 2010, 25th 17

Operating conditionsContentsPROJECT:Lubrication SystemCalculationGeometry ofsystemOverview :Simulation modelMain features ofthe integratedmodelInput DataOperatingConditionsResultsConclusions andfuture workThe calculations have been conducted for the following operatingconditions:‣ “field condition”: oil temperature 90°C, nominal bearing clearances‣ “worst case” conditions 1: oil temperature 120° (pump map fromexperimental test), maximum bearing clearances‣ “worst case” conditions 2: maximum oil temperature 140°C (pump mapcalculated), maximum bearing clearancesBelow, the clearances used in the calculation for “field” and “worst” condition:Clearances Worst case Field conditionMain bearings [mm] 0.074 0.0525Con rod bearings [mm] 0.056 0.043Counterbalance shaft bearings [mm] 0.095 0.0775Tappets clearances [mm] 0.046+0.07*=0.116 0.03+0.07*=0.100Camshaft bearings (intake side) [mm] 0.06 0.045Camshaft bearing (exhaust side) [mm] 0.07 0.05*: increase due to cylinder-head temperature (assumed=100°C)Frankfurt - October 2010, 25th 18

Results: Base systemContentsGraphs below show pressure levels versus engine speedPROJECT:Lubrication SystemCalculationGeometry ofsystemOverview :Simulation modelMain features ofthe integratedmodelPressure decreases due to lessresistance in the oil circuitInput DataOperatingConditionsResultsConclusions andfuture workFrankfurt - October 2010, 25th 19

Results: Modified systemContentsGraphs below show vol. flow rate vs. engine speed for each consumerPROJECT:Lubrication SystemCalculationGeometry ofsystemOverview :Simulation modelMain features ofthe integratedmodelInput DataOperatingConditionsResultsConclusions andfuture workPiston cooling jet flow decreases inworst case condition due todecrement of oil pressure in themain galleryThe piston cooling jet characteristicsinfluence whole system pressureand flow rateMain bearing flow rate increaseswith temperatureFrankfurt - October 2010, 25th 20

Conrod bearings: minimum oil film thicknessContentsPROJECT:Lubrication SystemCalculationGeometry ofsystemOverview :Simulation modelMinimum Film Thickness Study for worst possible conditionAssuming a worst case conditionwith maximum leakage through camphaser (~5L/min)Min. film thickness > 0.5µm for allcon rod bearingsMain features ofthe integratedmodelInput DataOperatingConditionsResultsConclusions andfuture workFrankfurt - October 2010, 25th 22

Cam Phasers Diameter variableContentsPROJECT:Lubrication SystemCalculationCam phaser leakage influence on rest of systemeven at worst (max) phaser leakage condition, there is adequate flow to mainbearings and piston cooling jetsGeometry ofsystemOverview :Simulation modelMain features ofthe integratedmodelInput DataOperatingConditionsResultsConclusions andfuture workFrankfurt - October 2010, 25th 23

Computational timeContentsPROJECT:Lubrication SystemCalculationGeometry ofsystemOverview :Simulation modelMain features ofthe integratedmodelIntegrated model is characterized by the following situationin terms of computational time using one workstationequipped with an Intel Xeon 3.33Ghz , 3 GB RAM:Simulation time is strongly affected by reaching convergenceon bearing flow and thermal balance!Mean value bearing model offers possibility to run muchfasterInput DataOperatingConditionsResultsConclusions andfuture workFrankfurt - October 2010, 25th 24

Mean Value Bearing ModelContentsPROJECT:Lubrication SystemCalculationGeometry ofsystemOverview :Simulation modelMain features ofthe integratedmodelMean value bearing model replaces predictive bearings(JournalBearingFlow) with flow rate lookup tables (FlowMaps)DOE run on predictive bearing solution sweeping RPM, P, T,clearanceDOE results for flow and power loss placed into FlowMapResult: much faster running model with nearly identical resultsDetailed ModelMean Value ModelInput DataOperatingConditionsResultsConclusions andfuture workFrankfurt - October 2010, 25th 25

Conclusions and future worksContentsPROJECT:Lubrication SystemCalculationGeometry ofsystemOverview :Simulation modelMain features ofthe integratedmodelInput DataOperatingConditionsResultsConclusions andfuture workConclusions‣ A detailed model of whole engine lubricating system has been developedin the GT-SUITE environment‣ Lubrication model (flow) integrated with detailed cranktrain model(mechanical) to account for proper bearing loads due to cylinder pressureand cranktrain/balance shaft mass/inertia‣ The developed model allows optimization of lubricating systemcharacteristics and layout from early stage of engine designFuture developments‣ Further validation through experimental test‣ Reduce computational time via:‣ Distributed computing‣ Simulation of crankshaft using 3D-dynamic option with stiffness of eachcranktrain and system solved in a dynamic mannerFrankfurt - October 2010, 25th 26