"Lube System Modelling and Validation, Including a Detailed Lube Pump" 14 November 2016 Riccardo Meldolesi, Clive Lacy

"Lube System Modelling and Validation, Including a Detailed Lube Pump" 14 November 2016 Riccardo Meldolesi, Clive Lacy

Contents Engineering Program Details Baseline engine characterisation Comparison with measurements Engine upgrade - Technologies to reduce oil demand Engine upgrade - Comparison with measurements Conclusions Appendix 1 - Detailed gerotor pump modelling Appendix 2 - Variable Displacement Vane Pump modelling 2

Engineering Program Details 1. Use of GT-SUITE to characterise the lube system of an existing baseline engine & correlate to measured pressure versus flow data 2. Extended model to perform oil pump sizing for new but similar engine version Reduced idle speed Different block layout, new filter & cooler 3. Investigated technologies to reduce engine oil flow requirement Minimise friction & pump size Investigate Packaging a Variable Displacement Vane Pump (VDVP) 3

Engine Features Gasoline, Port fuel injection 4 Cylinder 2.3 litre, turbocharged Cast iron block with aluminium head Gerotor oil pump Piston cooling jets (x4) Twin balancer shafts (plain bearings at each end) Type 1 Valvetrain with Hydraulic lash adjusters (x16) Intake & exhaust cam phasers 4

Base Engine Pressure Vs Flow characteristics 5

Baseline Lube Model - Features Modelled flow users first:, PCJs, Valvetrains, phasers, Timing drive, Turbo Temperature dependent clearances At Cam bearing & HLA bore, based on thermal FEA results Detailed piston cooling jet model (flow test data was available) Speed dependent bearing loads (look-up tables) Cam phaser oil control valve (OCV) leakage based on measurements Camshafts Block 6

Baseline Engine Model Correlation Model showed correct pressure-flow sensitivity to temperature out of the box [Bar, gauge] 8 6 4 2 B236 Meas. 3000 rpm 80 C Flow into Engine / Main Gallery Pressure Meas. 105 C Meas. 95 C Meas., 3000rpm 125 C 0 0 10 20 30 40 50 60 70 80 Flow [l/min] 8 Main Gallery Pressure Versus Flowrate 7

New Engine Contents Definition 8

Lube Model of New Engine GT-Suite Model extended to include: Camshafts Definition of 2 / 3 rds Mean to Max Clearance Max. Clearance 2/3rds Mean to Max. Mean Clearance Exact circuitry from CAD (GEM 3D tool used) New oil cooler (supplier measured P Vs flow) FlowPDropTableRef Object used to ensure correct P Vs temperature response New oil filter (supplier measured P Vs flow) Modelled with a PipeCrossSection object Pressure drop vs. flow rate close to linear Detailed model of pressure relief valve (PRV) Detailed lube pump leakage model (next slide) Block Min. Clearance Front cover circuitry & pump 9

Gerotor Pump Maps Generation Sub-model of pump internal leakages Built to generate pump vol. eff. maps at different oil temperatures Leakages strongly affected by oil temperature at lower speeds Viscosity & clearances Filling / cavitation effects more dominant at high speeds Cavitation effects derived form measurements (VolEff @ 0 P) Good match of P Vs Flow gradients to pump bench tests(102 C) Temperature dependent gradients PRV open 10

Required Pump Capacity [cc/rev] Technologies to Reduce Oil Demand 30 25 20 15 10 5 0 Flow Contribution [%] Flow Rate [l/min] 405 4 30 3 20 2 101 0 GP: 0.85 bar GP: 0.85 bar Total: 14.9 l/min Total: 14.9 l/min Assumes 80% pump efficiency GP: 0.79 bar GP: 0.79 bar Total: 12.2 l/min Total: 12.2 l/min Engine Speed: 700 rpm GP: 0.84 bar GP: 0.84 bar Total: 11.5 l/min Total: 11.5 l/min GP: 0.86 bar GP: 0.86 bar Total: 10.4 l/min Total: 10.4 l/min Selected Build (~30% lower flow than baseline) GP: 0.93 bar GP: 0.93 bar Total: 7.7 l/min Total: 7.7 l/min 130 C 130 C 130 C 130 C 130 C 130 C 130 C 130 C 130 C OBJECTIVE: minimise oil pump required size for reduced losses, & potentially enable packaging of a variable displacement vane pump (VDVP) 700 rpm 130 C Oil T 0.85 bar Gallery Pressure (GP) target Main Conrod Balancer Front Balancer Rear HLAs Piston Cooling Camshaft Turbo Leakage Phasers Other 20 15 15 10 10 5 5 0 Engine Speed: 3000 rpm Build #1 Build #2 Build #3 Build #4 Build#6 Baseline Graded Graded Graded GradedMain Main bearing Main Conrod Reduced max. Rolling element Rolling element Conrod Baseline Baseline Balancer Rear balancer bearing only clearance bearing bearingbalancer Front Front Balancer Balancer Rear Rear Hydraulic Hydraulic Hydraulic Hydraulic Mechanical HLAs HLAs Tappets Piston Piston Cooling Cooling Camshaft Camshaft Turbo Turbo Leakage Leakage Phasers Phasers 11

New Engine Correlation Check 12

Lube System & Instrumentation Layout Head machined for pressure & temperature measurement at the head to block location Cam cover machined for pressure measurement of cam phaser OCV circuit pressure Fittings at the rear of the head installed to measure head gallery pressures (intake & exhaust) 2.4 mm orifice restrictors installed to control Head oil flow Oil filter adapter machined to install a oil flow meter Flo To flow meter Spacer block to allow pressure and temperate measurements pre and post oil cooler 13

[Bar Gauge] Comparison with Measurements 8 7 6 5 4 3 2 1 Out of the box Simulation results Pump Outlet Pressure vs. Engine Flow Rate at 90 C Sim. Clr Range Sim. Mean Clr. Measured [Bar Gauge] 7 6 5 4 3 2 Main Gallery Pressure vs. Engine Flow Rate at 90 C Simulated pressure vs. flow at mean clearances good match to measured data 2/3 rds Mean to Min. 2/3 rds Mean to Max. 1 5 10 15 20 25 30 35 40 [litres/min] Simulated 14

Comparison with Engine Measurements [Bar Gauge] [Bar Gauge] 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 Cylinder Block Main Gallery: 90 C Cylinder Block Main Gallery: 130 C Cylinder Head (Exhaust End): 90 C 2/3 rds Mean to Min. 2/3 rds Mean to Max. 1000 2000 3000 4000 5000 Engine Speed [rpm] Close agreement at critical hot idle case Sim. Clr Range Measured Sim. Mean Clr. Cylinder Head (Exhaust End): 130 C 1000 2000 3000 4000 5000 Engine Speed [rpm] PRV Model needs tuning Measured results closer to 2/3rds mean to max. bearing clearance case at both temperatures Since pressure vs flow correlates well with mean clearances (previous slide) this suggests the pump volumetric efficiency in the engine may be lower than predicted Pump & PRV clearances to be measured at first engine inspection teardown. Pump bench testing might also be required 15

Summary GT-SUITE has been successfully used to fully model the lube system of a new engine design The model was built to characterise the highly temperature dependent pressure vs flow characteristic measured on an existing baseline engine Obtained correct pressure-flow sensitivity out of the box The model also was used to investigate technologies for flow reduction (hot idle) to minimise pump size & power consumption A new gerotor oil pump capacity required was determined for the new engine Simulation results show very good agreement with measured pressure vs flow, work is on-going to investigate some lower than expected pressures versus engine speed In addition, a variable displacement vane pump (VDVP) is being investigated for packaging & performance and fitting on future engine versions. Work is ongoing 16