Advanced C

Technology 

High Efficie

Combu

A

ugust 4t

Donald S

Research & T
Innovation 

Product Attributes Influen

Combustion Strateg

 Significant fuel economy improveme

 Customer driven Legislative initiatives

 Vehicle heat rejection Substantial increase in power densi

 Hybrid powertrain integrationVehicle electrificationEngine downsizing

 Cost 

*Power Density = power/weight
Innovation 

354045505560

1985 1990 1995 2000 2005 

Historical Perspective of H

Thermal Efficiency

Brake Thermal Efficiency (%)HECC DoE Effort Advanced Mixed Mode Combustion Air Handling (Air on Demand – Electronically Assis

HPCR Fuel System Technology Sensors / Controls Development Advanced Engine Co
Innovation 

EGR Loop

Fuel System A

Technology 

for Efficiency Impr

Variable 

Valve

Actuation

Variable Intake

Swirl

Turbo

Technology

Aftertreatment

Integration of Cummins Compone

Technologies in a Cost Effectiv

Integration of Cummins Compone

Technologies in a Cost Effective 

Hybrid

6.7L ISB 6.7L ISB 15L ISB 15L ISB
Innovation 

0.0 0.2 0.4 0.6 0.8 

BSNOx [g/hp-hr]

BSDPM [g/hp-hr]

EGR+DOC+DPF

+

SCR

In-Cylinder NOx Control

EGR+DOC+DPF

SCR NOx Conversion Efficiency 82%82%-86-86%% 

Δ=0.1

2007 Engine F

Advanced Fuel Injection System + EGR System + 

EGR System + Combustion System + Air Handling

Air Handling + Sens

Low ΔP, High Flow Rate EGR + VVA - S

Robustness

Advanced Combustion Concepts - Si

0.0

Achieving a Wide Range of Engine Out NO
Innovation 

0.0

Engine Out BSNOx (g/h

BMEP (bar) BMEP (bar)

0.2 0.4 0.6 0.8 

1-stage turbo

+

Low ΔP, HP Loop EGR

smoke ≤ 0.4 FSN smoke ≤ 0.4 FSN

SC

Op

Smoke ≤

 

0.4 FSN Smoke ≤

 

0.4 FSN

Fixed 

2-stage

turbo

Advanced EGR

System

Increased PCP

Assumed Constant Engine Displacement

Advanced Fuel Injection System 

and Combustion System Optimization

Advanced Fuel Injection System 

and Combustion System Optimization

Powe

M

Co

Mi

Co

LTC – Advanced

Combustion

LTC – Advanced

Combustion
Innovation 

Combustion Strategy fo

Economy Improveme

SPEED (rpm)

TORQUE (ft-lbs)

Early PCCI

Conventional

Diffusion Controlled

Moderate EGR Rates

Diffusion Controlled

Poor Efficiency

Moderate PM and NOx

High Efficiency

Low PM and NOx

SPEED (rpm)

TORQUE (ft-lbs)

Early PCCI

Conventional

Diffusion Controlled

Moderate EGR Rates

Diffusion Controlled

Poor Efficiency

Moderate PM and NOx

High Efficiency

Low PM and NOx

0

200400600800

100012001400

400 600 800 

TORQUE (ft-lbs)

1600

0

200400600800

100012001400

400 600 800 

TORQUE (ft-lbs)

1600

Early PCCI

Smokeless

Rich

Conventional Diesel

Late PCCI
Innovation 

Extending the Range of Ea

TDC

Crank A

Cannot inject in 

(ign. delay too 

Early PCCI 

PCCI ignition

and burning

compression

temperature PCCI

injection

La

in

Mode Advantages Disad

Early PCCI

- Good stability- Good fuel consumption

- High peak c- Limited BME- Noise- Higher coole

Late PCCI

- Low peak cyl. pressure

- High BMEP capability (20 bar)

- Low noise

- Narrow stab- Higher fuel c- Needs comb

0

200400600800

100012001400

400 600 800 1000 1200 1400 1600 1800 2000

TORQUE (ft-lbs)

Early PCCI

Lifted Flame Diffusion

Controlled

1600

SPEED (rpm)

0

200400600800

100012001400

400 600 800 1000 1200 1400 1600 1800 2000

TORQUE (ft-lbs)

Early PCCI

Lifted Flame Diffusion

Controlled

1600

SPEED (rpm)
Innovation 

Challenges for Full Engine O

in PCCI Combustion

0

200400600800

100012001400160018002000

600 1100 1600 

Engine Speed [r/min]

Torque [FT-LBS]

High Load

• Rate of pressure rise

• Controls (Mode switching and sta

• Mixture preparation

•EGR rates and vehicle cooling

Light Load

• Combustion Noise• Efficiency (UHC and CO)• Controls (Mode switching and stability)• Mixture preparation
Innovation 

Brake Thermal Eff. (%)

Smoke (FSN) 

Extending the Engine Operation Rang

Combined Combined Early and Late PCCI Early and Late PCCI

Reduce CO & UHC while

maintaining acceptable NVH

(especially below 5 bar BMEP)

Reduce CO & UHC while

maintaining acceptable NVH

(especially below 5 bar BMEP)
Innovation 

SOI=-5 ATD

Injector 

Equivalence Ratio Contours

1% to 3% bsfc reduction

Sandia-

Images Courtesy of Mark Musculus - SNL

Engine data from

2–9 bar BMEP with 

3 to 7 injection events

Engine data from

2-10 bar BMEP with a 

combination of single 

and dual injection

Reducing HC and CO for 

Efficiency Im

“Ignition Dwell” ≡ Time from end of injection to start of combustion 
Innovation 

Brake Thermal Eff. (%)

Smoke (FSN) 

Extending the Engine Operation Rang

Combined Combined Early and Late PCCI Early and Late PCCI

Late PCCI limit

improvement poten

Late PCCI limits 

improvement poten
Innovation 

0

200400600800

100012001400160018002000

600 1100 1600 

Engine Speed [r/min]

Torque [FT-LBS]

Extending PCCI Combus

with VVA

4% Fuel Economy at 

0.2 g/bhp-hr NOx

Imp

Impa

2% Fuel Economy at 

0.2 g/bhp-hr NO

x

3% Fuel Economy at 

0.2 g/bhp-hr NO

x

Optimization w

0

102030405060708090

Late

IVC

Std IVC Late

IVC

Std IVC Late

IVC

Std IVC Late

IVC

Std IVC Late

IVC

Std IVC

A_F egr SOI INT_MNF_P EXH_MNF_P

0

102030405060708090

Late

IVC

Std IVC Late

IVC

Std IVC Late

IVC

Std IVC Late

IVC

Std IVC Late

IVC

Std IVC

A_F egr SOI INT_MNF_P EXH_MNF_P

1600 RPM @ 1230 ft-lb

Main SOI

TDC

Crank Angle

ignition dela

y

too short

Cannot inject in this rang

e

(ign. delay too short)

Early PCCI Late PCCI

Late PCCI ignitio

n

and burnin

g

PCCI ignition

and burnin

g

compression

temperatur

e PCCI

injectio

n

Late PCCI

injectio

n

VVA
Innovation 

Challenges for Lifted Flame C

 Creating desired intake valve closing c

A/F, EGR, IMT

 Fuel injection system technology

 Injection pressure Nozzle configuration

 Fuel injection plume to plume 

interaction

 Combustion surfaces

 Difficult to scale to smaller bore engines

 Controls development for transient ope

0

200400600800

100012001400

400 600 

TORQUE (ft-lbs)

1600

0

200400600800

100012001400

400 600 

TORQUE (ft-lbs)

1600
Innovation 

Conventional D

Lifted Flame D

Lift Off Length

4≤ φ

 

≤ 6

2≤ φ

 

≤ 3

1≤ φ

 

≤ 2 Advanced Lifte

(Scales well for 

Reduce Liquid Fuel Penetration 

and Enhance Fluid Entrainment

Creating Lifted Flame C

Eliminate

Liquid Injection

Reduced

Liquid 

Penetration
Innovation 

0.8

fsNOx(g/kgfuel)

fs

DPM(g/kg

fue

l

)

1.0 1.5 2.0 2.5 3.0 3

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.0

Baseline Recipe Baseline Recipe

Direct Injection - Simulations Direct Injection - Simulations

Fumigated + Direct Injection 

Fumigated + Direct Injection - 

Advanced Lifted Flame C

1600 RPM at Full Load
Innovation 

Achieving High Efficiency Com

with a Wide Portfolio of F

 Wide variety of fuel types Engines designed and sold for a glob Mixed mode combustion Robustness of operation Maintain fuel efficiency gains Exploit fuel properties for performanc

Virt
Innovation 

Exploration of Fuel Proper

HECC*

 Use transient engine operation as key da

understanding impact of fuel properties on 

 Explore the impact of fuel type over a var

advanced combustion modes

 Characterize the fuel compounds and pro

• Challenging for heavy fuels

 Explore real and virtual fuel quality senso

engine integration

 Development of kinetics mechanism for a

• CFD analysis – primary way to generalize ke

knowledge gained from external collaboration

*Partners: ORNL and BP
Innovation 

PCCI Engine Performance Variation with ULSD

1.4 1.6 1.8 2 2.2 2.4 2.6 

05

101520

Frequency

NOx (g/kg)

Frequency distribution of NOx

1.5 2 2.5 3 3.5 0

204060

Frequency

Smoke (FSN)

Frequency distribution of Smoke

0.25 0.255 

05

10152025

Frequency

gisf

Frequency 

Frequency

fsNOx, gisfc, smoke, etc = f(engine parameters) + f(
Innovation 

0.8 1 1.2 1.4 1.6 

05

10

Frequency

NOx (g/kg)

Frequency distribution of NOx

0.8 1 1.2 1.4 1.6 

0

50

100

Frequency

NOx (g/kg)

Frequency distribution of NOx

2 2.2 2.4 2.6 2.8 0

50

100

Frequency

Smoke (FSN)

Frequency distribution of Smoke

2.3 2.4 

05

10

Frequency

Frequenc

0.2 0.4 0.6 0.8 1.0 0.2 0.4 

Non-Prem

Non-Pre

Non-

Non

Prem

Prem

Premium Fuel Premium Fuel
Innovation 

Exp

Expe

Model Prediction Model Prediction

O2 Sensor-Based BioContent Estimation O2 Sensor-Based Bio- Content Estimation

Virtual Se Virtual Sensor Technology nsor Technology

Biofuels 

Courtesy: Professor Shaver – Purdue University
Innovation 

Summary Mixed mode combustion can achieve a wid

engine out NOx (≥0.2 g/bhp-hr)

 Select the right technology for each applicatio

 Development and integration of componen

are key enablers

 Additional technology exploration needed t

emission robustness and fuel economy at 0.2 out NOx

 Advanced combustion strategies are being ex

lifted flame combustion and extended range P

 Virtual and real fuel sensors are enablers fo

performance while maintaining high efficiencproperties variation increases
Innovation 

Variable Swirl – Emiss

Robustness

Speed (RPM)

BMEP (bar)

1000 1500 2000 2500 

10

98765432

LDD Recommended Swirl - Solid Body Ro

KIVA Recommended Swirl

22% Reduction in 

2.5% - 3.5% Fuel Ec

22% Reduction in 

2.5% - 3.5% Fuel Eco

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

12345

DCS Swirl #

fsDPM (gm/kg)

Varying A/F Ratio

DCS Swirl

KIVA Recommendation