Hinduja Tech Limited A Hinduja Group Company

Lubrication System Analysis and Oil Pump Power Consumption Reduction

Author: Madhusudhan R Co Author: Prasanth B

Contributor: Meenakshi Sundaram I

www.hindujatech.com

Contents

Objective and overview

Methodology

GT-Suite 1D Simulation model

Single cylinder analysis

Component characteristics

Results

Optimisation

Summary

2

Objective and Overview

Flow Distribution and Power Consumption

Product Development Time reduction

Improving System Reliability

Competency Building

1D System Model in GT-Suite

Single cylinder GT-SUITE model

Full scale GT-SUITE model

Validation with test results

Optimisation of configuration

Optimized lubrication system

Lubrication system layout Work flow

3

Methodology

Model Verification

The GT-SUITE-model is validated against the

test bed results and found to have acceptable

correlation with variation of less than 10%.

1

1.5

2

2.5

3

3.5

4

0 1000 2000 3000 4000

MO

G p

res

su

re (

ba

r)

Speed (RPM)

Test result GT - Simulation

Predicted vs Tested Results

•Layout of the system

•Gallery dimension

•Component locations

•Components

Characteristic

•Oil pump

•Oil filter

•Oil cooler

•Piston cooling jet

•HLA

Bearings

1. Predictive method

2. Mean value

Pump

1.Pump flow

2.Pump positive

displacement

3.Pump external gear

4.Pump

5.Detailed Pump model

Clearances

1.Constant

2.Non-constant

Flow

1.Geometry

2.Predictive method

3. Flow map

Lubrication system 1D MODEL GT-SUITE

•Oil characteristics

•Speed and Bearing load

Bearing load

1.Auto

2.User defined

•Analysis

•Periodic analysis

•Explicit Solver

Output

•Gallery pressure

•Bearing performance

•Flow distribution

•Pump flow

•Power consumption

4

GT-SUITE 1D Model

Main bearing Conrod bearing PCN Oil gallery

Cranktrain

Cam bearing Oil cooler and oil filter

Oil Pump

HLA Oil Rail

5

Single Cylinder Analysis

• Optimize bearing groove size

Groove Volume

• To locate oil hole in bearing

Oil hole angle & size

• For optimal gallery pressure

Gallery diameter

Inputs and Considerations

1. Single cylinder pressure profile

2. Constant pump flow based on

flow estimation

Outcome

1. Bearing geometry is finalized

Single cylinder model Objective

Results

Gallery pressure for different oil inlet hole location and diameter 6

Oil Pump Characteristics

Pump type used is Gerotor pump

The Oil pump sizing is done based on the initial

flow estimation

Initial flow estimation is given a flow rate

cushioning of 1.45 times of flow requirement for

vapor loses, pump wear, hot idle condition etc.

Physical model of the pump was tested and flow

rates are input in GT-SUITE model

Pump flow characteristics are imposed in the

Lubrication model through “Pump” template.

Pump map is given for temperature values of 95

and 110˚C

7

Relief Valve Characteristics

Relief valve was constructed as spring based

conventional type

Pressure relief valve senses pump exit pressure

Relief valve is modeled through predictive method

Stiffness of Pressure relief valve is set as 2.95

N/mm

Physical model tested and input to GT-SUITE

model as a ‘FlowMap’ template

Oil Properties

Oil grade used is SAE 5W-30

Properties Unit Value

Kinematic viscosity @ 40˚C cSt 65

Kinematic Viscosity @100˚C cSt 11.2

Density @ 15˚C Kg/m3 863

0

5

10

15

20

25

30

35

0 200 400 600 800

Flo

w (

lpm

)

Pressure (kPa)

Relief Valve Characteristics

8

Oil filter & PCN Characteristics Oil cooler and oil filter are given are imposed in the GT-

SUITE model in the form of ‘PressureLossConn’ object

The Oil filter are given as Pressure drop vs. Oil flow

rate curves through ‘FlowPDropTable’.

Piston Cooling Nozzle (PCN)

• Piston cooling nozzle is separately made

as a predictive model

•Obtained flow rates are imposed in the

lubrication model as flow map.

•The spring based cooling nozzle’s

stiffness was set to 0.597N/mm

GT-SUITE – PCN Predictive model

0

0.5

1

1.5

2

2.5

0 1 2 3 4 5

Flo

w (

lpm

)

Pressure (bar)

PCN flow map

9

Bearings Characteristics

• Bearings are modeled through Predictive method

• Bearings are assumed to be constant clearances

• Bearings are assumed to remain as circular geometry

• Cylinder pressure profiles calculated from GT-POWER are fed in lubrication model to calculate

bearing loads

• Martin and modified martin equations are chosen for main and conrod bearings respectively

Cylinder Pressure Profile

Design inputs from single cylinder analysis

• Based on single cylinder analysis the following

data were finalized

-Oil entry hole diameter of main bearing

-Oil entry hole location

-Groove depth and width

10

Results Gallery pressure Gallery pressure fluctuation

Flow Distribution Oil film thickness

Max gallery pressure was 502kPa Pressure fluctuation in oil gallery was <50kPa

Oil film thickness in main bearing and

conrod bearing was 0.75 and 0.48microns

11

Optimisation

Objective

•Oil pump power consumption to be reduced

Scope

•Higher gallery pressure observed in prediction

•Flow through relief valve provided large scope

for optimisation

•Relief valve spring optimisation was done GT-

SUITE

Reduced pump flow Optimized relief valve

Pump flow

Relief Valve

Power Saving

Reduce pump flow

Modify relief valve

setting

0

2

4

6

8

10

12

14

16

18

0 100 200 300 400 500 600

Flo

w (

lpm

)

Pressure (kPa) 12

Results Gallery pressure

Flow Distribution Power Consumption comparison

0

50

100

150

200

250

300

350

0 1 2 3 4

Po

we

r (W

)

X1000 RPM

Pump- 1

Pump 2

Film thickness

Oil gallery pressure reduced to 396kPa Film thickness of main bearing and conrod bearing

were 0.71 and .46 microns

13

Summary & Future Work

Influence of various component features on lubrication system studied.

A complete engine model was built in GT-SUITE to estimate system pressure and flow.

To optimize power consumption, pump flow and relief valve characteristics were modified.

The optimized pump flow lowered the operational pressure of oil gallery uncompromised operating

condition for bearings, HLA, turbocharger.

Maximum oil gallery pressure was reduced by 20% without affecting the performance of critical

components

Power saving of 8%was achieved by optimising the oil pump flow and relief valve setting

Future work

Modeling oil pump in 1D platform

Coupling thermal and frictional model with lubrication system to understand the dynamic conditions

Oil carry over estimation and Oil life estimation

14

Contributors

• Meenakshi Sundaram I

• Sriprakash D B

• Balaji V

• Balasubramani K

• Bharathan S

• Vignesh J

• Prasanth B

• Varun V

15

THANK YOU !!!

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