a heavily downsized gasoline demonstrator engine

© MAHLE

A Heavily Downsized Gasoline Demonstrator

Engine Future Powertrain Technology Conference

February 24th – 25th, 2016

Mike Bassett1, Ben Hibberd1, Jonathan Hall1,

Kevin Gray2 and Bryn Richards2

1MAHLE Powertrain Ltd, Northampton, UK. 2Aeristech Ltd, Kenilworth, UK.

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MAHLE Powertrain Ltd., Research & Advanced Engineering, Dr. Mike Bassett, 24th February 2016

Introduction

Future Engine Technologies

Why Downsize?

– Downsizing Challenges

– Downsizing Benefits

MAHLE Downsizing Demonstrator

eSupercharged Downsizing Engine Concept

– Aeristech eSupercharger

– Boosting System Layout

Testing Status

Conclusions and Next Steps

A Heavily Downsized Gasoline Demonstrator Engine

© MAHLE

Contents

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Legislation, Consumers and Manufacturers are

continually seeking the following vehicle improvements:

– Better Fuel Economy

– Lower Emissions

– Better Performance

– Lower Cost

These ongoing demands will intensify


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Introduction

3


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Future Gasoline Engine Technologies

Friction Reduction

Hybridisation

Combustion Process

Variable Valvetrain

Weight Optimisation


4

Downsizing Direct Injection

Increased peak cylinder pressures

Charging / Variable Geometry

Turbines

Downsizing

Direct Injection



Turbines

Downsizing Direct Injection



Turbines

MAHLE Powertrain Ltd., Research & Advanced Engineering, Dr. Mike Bassett, 24th February 2016 © MAHLE

Downsizing Technical Challenges

Compression

Ratio

Combustion System

Part Load

Efficiency


High Load Fuel

Consumption

Exhaust Gas Temperatures

Steady State Low

Speed Torque Transient Response

Low Speed Driveability

5

Downsizing Technical

Challenges


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90

100

0

5

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0 10 20 30 40 50 60 70 80 90 100

BMEP [bar]

Fuel

/ CO

2Re

duct

ion

[%]

Degree of Downsizing [%]

Downsizing effect

Friction corrected

Friction + CR corrected

Specific power

Current production engines

500

400

300

200

100

0

Specific Power O

utput[kW/litre]

Single stage charging

Multi stage charging

DownsizingEffect CR

Friction

160 kW/l32 bar BMEP

120 kW/l24 bar BMEP

Specific Power/ BMEP

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A Heavily Downsized Gasoline Demonstrator Engine Downsizing Benefits

Estimates based on 3.2 litre N/A base engine in a D-segment vehicle tested on NEDC

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MAHLE Powertrain Ltd., Research & Advanced Engineering, Dr. Mike Bassett, 24th February 2016 © MAHLE

A Heavily Downsized Gasoline Demonstrator Engine MAHLE Downsizing Demonstrator

MAHLE working on Downsizing engine developments

for over 7 years

MAHLE developed a technology

demonstrator engine in 2007

– Achieved 30 bar BMEP

and 100 kW/litre

Demonstrator vehicle built in 2010 to showcase the

engine

– 30 % reduction in fuel consumption

Continuous development looking into

– Reduction of losses

– Increased high & part load efficiency

– Thermal-Management

– Alternative fuels, …

Next Generation of Downsized Engines

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Main Dimensions and Engine Data

Configuration - In-line 3 Cylinder

Capacity cm3 1200

Bore mm 83.0

Stroke mm 73.9

Compression Ratio - 9.3 : 1

Turbocharger -

Bosch MAHLE Turbo

Systems

1-stage, Waste Gate

Peak Power kW 120 (5000-6000 min-1)

Specific Power kW/l 100

Peak BMEP bar 30 (1600-4000 min-1)

© MAHLE

A Heavily Downsized Gasoline Demonstrator Engine MAHLE Downsizing Engine Specifications

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© MAHLE

eSupercharged Downsized Engine Concept

Parameter Value

Compressor type Radial

Motor High-speed PM

Max operating speed 120,000 min-1

Lubrication Greased for life

Cooling Liquid

Input voltage 48 V nominal

Unit mass 4.2 kg

Key enabler is a boosting system which:

Provides very high air flow & boost pressure

Enables good transient response at any engine speed

Aeristech production intent design:

Fully integrated power electronics

1st prototype built and successfully

bench tested

Power ratings

– Peak power 8.8 kW

– Continuous power 5.6 kW

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© MAHLE

eSupercharged Downsized Engine Concept

Key features of the system are:

MAHLE Di3 downsized engine

Aeristech eSupercharger

High mass-flow and pressure ratio turbocharger

Vehicle-packaged intake and exhaust system

48 V DC Aeristech power electronics

48 V Belt starter generator capable of powering eSupercharger

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6060

BM

EP

[b

ar]

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Engine speed [min-1]

1000 2000 3000 4000 5000 6000 7000

kW/l

Single turbo 120 kW (100 kW/litre) Turbo only 193 kW (161 kW/litre) eSupercharger + Turbo

Typical Mainstream Boosted Engines: TGDI Prod'n Engines (Single Turbo) TPFI Prod'n Engines (Single Turbo)


© MAHLE

Engine Testing Status

Performance

Current status of project:

Power of 160 kW/L exceeded

– Low speed torque poor with turbo only

eSupercharger lifts low speed torque to over 25 bar

BMEP from 1000 min-1

Combined eSupercharged and turbocharged torque

curve above 30 bar BMEP from

1500 to 5500 min-1

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BMEP [kPa]

BMEP [kPa]

BM

EP

[bar

]

0

5

10

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25

30

35

Time [seconds]

-1 0 1 2 3 4 5

Single turbo 120 kW (100 kW/litre) Turbo only 193 kW (161 kW/litre) eSupercharger + Turbo

© MAHLE


1500 min-1 Load Step Response

Transient Response:

Knee point to 90 % of max torque :

– 120 kW baseline engine

23.4 bar in 3.3 s

34 Nm/litre/second

– 193 kW engine turbo only

12.6 bar in 2.0 s

11 Nm/litre/second

– 193 kW turbo

+ eSupercharger

29.7 bar in 1.2 s

156 Nm/litre/second

29.7 bar

1.2 secs

Knee

Point


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© MAHLE


Combustion Phasing

0

10

20

30

40

Engine speed [min-1]

1000 2000 3000 4000 5000 6000 7000

Co

mb

ustio

n P

ha

sin

gM

FB

50

% [ºC

A A

TD

C]

Single turbo 120 kW (100 kW/litre) eSupercharger + Turbo

BM

EP

[b

ar]

15

20

25

30

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Combustion phasing:

Baseline engine

– Combustion phasing retarded from optimum at

low speeds

– Knock limited

eSupercharged engine combustion phasing similar to

baseline

– Higher load

– Same compression ratio

eSupercharger enables good scavenging of EGR from

cylinder

– With low exhaust O2

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© MAHLE

Conclusion and next steps

Project conclusions

Performance targets achieved or exceeded

– λ = 1.0 operation for large portion of

operating map

High load

Reasonable CR

Aeristech’s eSupercharger shown to provide:

– Sustained high mass flow and

– Sustained high pressure ratio

– Excellent transient response

Next steps

Finish full testbed based engine mapping

Install eSupercharged engine into a demonstration

vehicle, complete with 48V system architecture

37

a heavily downsized gasoline demonstrator engine

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