Oil Flow in Gasoline Engines

Christopher Hammond, John Lindsay Smith, Moray Stark, David Waddington

Department of Chemistry: University of York

Richard Gamble, Martin Priest, Christopher Taylor

School of Mechanical Engineering: University of Leeds

Harold Gillespie, Eiji Nagatomi, Ian Taylor

Shell Global Solutions (UK)

Introduction

Aim

To Predict Increase in Piston Friction with Oil Degradation• Chemical Model for Base Fluid Oxidation

• Rheological Model for Increase in Viscosity

• Tribological Model for Piston Friction

In This Talk

• Measure Fluid Flow in Piston Ring Pack

• Comparison with Tribological Model

• Chemical Model using Measured Flow Parameters

Engine Specification

Ricardo Hydra• Fuel Injected Gasoline • Single Cylinder• 0.5 litre Capacity• 1500 rpm• 50% Throttle• External Sump (70 ºC)• Camshaft Lubricated Separately

Shell XHVI ™ 8.2• No Additive Package

Lubricant Specification

Extraction of Oil from Top Piston Ring

1/8” PTFE Tube

Sample Collection

Piston Assembly

Oil Flow in Engine

Sump

Ring PackSmall VolumeShort Residence Time

Large VolumeLong Residence Time

Flow Rate

0

25

50

75

100

0 10 20 30 40 50

Time / arb

Ma

rke

r / %

Ring Pack Residence Time :ringpack

)exp1(]marker[]marker[ RINGPACK

TIME

sumpringpack

1-e-1

Ring Pack Residence Time : 60 sec

0

25

50

75

100

0 1 2 3 4 5

Time / min

Mar

ker

/ %

Ring Pack Residence Time – Previous Work

S B Saville, F D Gainey, S D Cupples, M F Fox, D J Picken, SAE Technical Paper, International Fuels and Lubricants Meeting, Oct 10-13, 1988

Oil Flow and Chemistry in Engine

Sump

Ring PackHigh Temperature Small VolumeShort Residence Time

Low Temperature Large VolumeLong Residence Time

Oxidation Chemistry

CC

CC

CC

CC

CC

CC

H

HH

H

HH

H

H

HH

HH

H

H

H

H

HH

H

H

H

HC

CC

H

H

H

H

H

HH

H

H

O

O

H

CC

CC

CC

CC

CC

CC

H

HH

H

HH

H

H

HH

HH

H

H

H

H

HH

H

H

H

HC

CC

H

H

H

H

H

HH

H

O

CC

CC

CC

CC

CC

CC

H

HH

H

HH

H

H

HH

HH

H

H

H

H

HH

H

H

H

HC

CC

H

H

H

H

H

HH

H

H

H

OC

CC

C

O

H

H

H

H

HH

HHCC

CC

CC

CC

CC

CO

H

HH

H

HH

H

H

HH

HH

H

H

H

H

HH

H

H

H

O

H +

Infrared Spectroscopyof Carbonyl Group

Hydrocarbon Base Fluid

Hydroperoxides

Ketones

CarboxylicAcids

Oxidation in Sump – IR Spectrospcopy

0

0.005

0.01

0.015

0.02

0 10 20 30 40 50

Time / hours

Ac

id +

Ke

ton

e /

mo

l d

m-3

0

0.2

0.4

0.6

Ca

lcu

late

d TA

N

Oxidation in Ring Pack

0

0.05

0.1

0.15

0.2

0 20 40 60 80 100

Time / min

Ac

id +

Ke

ton

e /

mo

l d

m-3

0

2

4

6

Ca

lcu

late

d TA

N

sump (x100)

ringpack

Oxidation in Ring Pack : Previous Work

S B Saville, F D Gainey, S D Cupples, M F Fox, D J Picken, SAE Technical Paper, International Fuels and Lubricants Meeting, Oct 10-13, 1988

0

0.01

0.02

0.03

0.04

0 10 20 30 40 50 60

Time / hours

Aci

d +

Ket

on

e / m

ol d

m-3

Caterpillar diesel (Oil A)

Caterpillar diesel (Oil B)

Sump Residence Time and Oil Flow Rates

dt

dSUMPRINGPACK

]Product[]Product[

13 mincm012.0271.0

SUMPSUMPRINGPACK

SumpVolumeFlowRate

Hours8156 SUMP

0

0.05

0.1

0.15

0.2

0 20 40 60 80 100

Time / min

Ac

id +

Ke

ton

e /

mo

l d

m-3

0

2

4

6

Ca

lcu

late

d TA

N

sump (x100)ringpack

Characterisation of Ricardo Hydra EngineRing PackResidence Time 60 ± 15 secondsVolume of Oil 0.30 ± 0.08 cm3

Temperature 200 °C

Flow RatesInto Ring Pack 0.32 ± 0.02 cm3

min-1

Returning to Sump 0.27 ± 0.01 cm3 min-1

Loss From Ring Pack 0.05 cm3 min-1

SumpResidence Time 156 ± 8 hoursVolume 3 litresTemperature 70 °C

Conditions: 1500 rpm, 50% Throttle

Piston Assembly

Comparison with Tribological Model

Ring Pack Experiment Theory

Residence Time 60 ± 15 10 seconds

Volume of Oil 0.30 ± 0.08 0.02 cm3

Flow Rates

Into Ring Pack 0.32 ± 0.02 0.17 cm3min-1

Returning to Sump 0.27 ± 0.01 0.12 cm3min-1

Loss From Ring Pack 0.05 0.05 cm3min-1

Sump

Residence Time 156 ± 8 300 hours

Conditions: 1500 rpm, 50% Throttle

Oxidation Chemistry

Hydrocarbon Base Fluid

Hydroperoxides

Ketones

CarboxylicAcids

DiketonesHydroxyketones

Current Mechanism

Two Reactor Simulation

Residence Time Volume TemperatureSump 156 hours 3 litre 70 CRing Pack 60 sec 0.27 cm3 200 C

0

0.05

0.1

0.15

0.2

0 20 40 60 80 100

Time / min

Car

bo

nyl

/ m

ol d

m-3

0

2

4

6 Calcu

lated TA

Nsump (x100)ringpack

Conclusions

• Measured Oil Flow in Gasoline Engine

• Modelled Fluid Flow in Ring Pack

• Modelled Base Fluid Oxidation in Engine