University of Technology, Sydney

Faculty of Engineering

INNOVATIVE PRODUCT DESIGN

CONCEPTUALIZATION WITH OIL-LESS

TWO-STROKE ENGINE AS A CASE STUDY

by

Holger Roser

A thesis submitted for the degree of

Master of Engineering (by Thesis)C03017

Sydney

August, 2003

I wish to dedicate this to my parents,

Manfred and Ellen Roser,

whose kindness, support, and care I am forever grateful.

CERTIFICATE OF ORIGINALITY

I certify that the work in this thesis has not previously been submitted for a degree nor

has it been submitted as part of requirements for a degree except as fully acknowledged

within the text.

1 also certify that the thesis has been written by me. Any help that I have received in my

research work and the preparation of the thesis itself has been acknowledged. In

addition, I certify that all information sources and literature used are indicated in the

thesis.

Signature of Candidate

1

ACKNOWLEDGMENT

First and foremost, I would like to express my grateful appreciation to both the people

and organisations involved in this project, for their support and contribution in

completing this project. I pay my sincere gratitude to my supervisors, namely

Mr. John Dartnall (Principal Supervisor)

Mr. Chris Tyree (Industry Supervisor and Sponsor)

Dr. Fred Sticher (Co-Supervisor and Lecturer)

for their inspiration, enthusiasm, guidance, and encouragement, which made this

research successful. Special thanks go to Mr. Chris Tyree of TyTeam Pty Ltd and the

Tyree Group for providing the funding without which this research would not have been

possible.

I also owe thanks to Robert Cleary, Dylan Buckley, and Robert Smith, all

undergraduate project students, for their invaluable assistance and contribution to both

construction and testing of the research engine.

Additionally, I wish to thank all the workshop and technical personnel at UTS for their

highly valued assistance, in particular

Mr. Chris Chapman

Mr. Charles Evans

Mr. Bill Firth

Mr. Scott Graham

Mr. Matthew Low

Mr. Harold Myers

Mr. Richard Turnell

(Scientific Officer)

(Technical Manager)

(Technical Officer)

(Technical Officer)

(Engineer Mechanical Laboratories)

(Technical Officer)

(Technical Officer)

Appreciation is also given to the UTS Faculty of Engineering for providing the

opportunity, facilities, and resources for this project. Special reference is made to the

assistance provided by Rosie Hamilton for her constant willingness to help with

administrative issues, and Professor Stephen Johnston for his invaluable support and

advice.

Finally, acknowledgements are due to my family and friends without their

encouragement and emotional support I would not have tackled this project.

TABLE OF CONTENTS

Certificate of Originality.................................................................................................... i

Acknowledgment.............................................................................................................. ii

List of Figures................................................................................................................. vii

List of Tables................................................................................................................... ix

Glossary and Notations..................................................................................................... x

Symbols..........................................................................................................................xiii

Abstract........................................................................................................................... xv

Chapter 1: Introduction.......................................................................................................1

1.1. Background and Motivation............................................................................ 1

1.2. Problem Formulation....................................................................................... 2

1.3. Research Objectives......................................................................... ...A1.4. Research Scope and Procedure........................................................................ 5

1.5. Thesis Outline................................................................................................. 8Chapter 2: Innovative Product Development - An Overview......................................... 10

2.1. Introduction....................................................................................................102.2. Definitions......................................................................................................12

2.3. Product Development Approaches................................................................ 13

2.3.1. A Fundamental Product Development Process.................................... 13

2.3.2. Strategies of Product Development...................................................... 18

2.3.3. Classification of Design....................................................................... 21

2.3.4. Sequential Product Development Process............................................ 22

2.3.5. Parallel Product Development Process................................................ 24

2.4. Product Design Management........................................................................ 27

2.4.1. Project Planning and Control............................................................... 27

2.4.2. Organisational Structure and Climate.................................................. 29

2.4.3. Cross-Functional Teams...................................................................... 31

2.4.4. Supplier and Customer Integration.......................................................... 32 .

2.4.5. Communication.................................................................................... 33

2.4.6. Information Management and Infrastructure....................................... 35

2.4.7. Continuous Design Documentation..................................................... 36

2.5. Chapter Review............................................................................................. 36

Section Page

Chapter 3: Conceptual Design Approaches - A Summation...........................

3.1. Introduction.....................................................................................

3.2. Definitions.......................................................................................

3.3. Design Methodologies....................................................................

3.3.1. Axiomatic Design by Suh......................................................

3.3.2. Systematic Engineering Design by Pahl & Beitz..................

3.3.3. Total Design by Pugh.............................................................

3.3.4. Theory of Inventive Problem Solving (TRIZ)......................

3.3.5. Contradiction Oriented Innovation Strategy (WOIS)...........

3.3.6. Computer Aided Design Tools and Artificial Intelligence....

3.4. Design for X....................................................................................

3.4.1. Design for Manufacturing and Assembly.............................

3.4.2. Design for Reliability and Durability....................................3.4.3. Design for Serviceability and Maintenance..........................

3.4.4. Design for Disassembly and Recycling................................

3.5. Chapter Review.......................................... ....................................

Chapter 4: Innovative Conceptual Product Design - An Enhanced Approach

4.1. Introduction.....................................................................................

4.2. The Importance of the “Fuzzy Front End”.....................................4.3. Environment for Innovative Engineering Design..........................

4.4. The ICD Framework.......................................................................

4.5. Identification of Need.....................................................................

4.5.1. Market Analysis.....................................................................

4.5.2. Identification of Customer Needs.........................................

4.5.3. Technology Analysis..............................................................

4.5.4. Case Study..............................................................................

4.6. Product Definition...........................................................................4.6.1. Functional Decomposition.....................................................

4.6.2. Objectives Tree Method.........................................................

4.6.3. Quality Function Deployment...............................................

4.7. Determination of Product Attributes..............................................

4.7.1. Function Analysis..................................................................

4.7.2. Setting of Specification Requirements..................................

4.7.3. Determination of Critical Design Issues...............................

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4.8. Concept Generation....................................................................................... 90

4.8.1. Creativity and Ideation......................................................................... 91

4.8.2. Morphological Analysis....................................................................... 92

4.8.3. Early Empirical Design........................................................................ 94

4.9. Concept Evaluation....................................................................................... 97

4.9.1. Weighted Objectives Method...............................................................98

4.9.2. Pugh Method.......................................................................................101

4.10. Concept Decision.........................................................................................102

4.11. Concept Classification and Evaluation Scheme - A Combined Matrix....104

4.12. Iteration and Refinements............................................................................109

4.13. Chapter Review.... ....................................................................................... 109

Chapter 5: Design in the Spotlight of TICS - Four Pillars of Design............ ........... 111

5.1. Introduction..................................................................................................Ill

5.2. Accelerated Product Design - The Time Focus.......................................... 1135.2.1. Benefits of Accelerated Product Design............................................ 114

5.2.2. Product Development Accelerators...................................................116

5.2.3. Risks and Implications........................................................................119

5.2.4. The Bottom Line.................................................................................121

5.3. Design for Originality - The Innovation Focus.......................................... 122

5.3.1. Technology Identification, Analysis, and Evaluation (TIAE)........... 1235.3.2. Innovation Risk and Technological Uncertainties............................. 126

5.3.3. The Bottom Line.................................................................................1285.4. Design for Affordability- The Cost Focus................................................. 129

5.4.1. Product Cost Management..................................................................130

5.4.2. Value Engineering.............................................................................. 131

5.4.3. The Bottom Line.................................................................................133

5.5. Reducing Design Complexity - The Simplicity Focus.............................. 134

5.5.1. Keep it Simple.....................................................................................135

5.5.2. Function Sharing................................................................................ 136

5.5.3. The Bottom Line.................................................................................138

5.6. Chapter Review....................................... 139

Chapter 6: Conceptual Design of an Oil-less Two-Stroke Engine - A Case Study... 140

6.1. Introduction.................................................................................................. 140

6.2. Case Study Background...............................................................................143

6.3. Engine Development Goals and Objectives................................................ 145

6.4. Engine Fundamentals and Definitions......................................................... 146

6.4.1. The Internal Combustion Engine........................................................ 147

6.4.2. The Two-Stroke Cycle........................................................................ 149

6.4.3. Scavenging.......................................................................................... 150

6.4.4. Engine Parameters.......................... 153

6.5. Preliminary Research and Determination! of Critical Design Issues........... 158

6.5.1. Stratified Charging.............................................................................. 160

6.5.2. Direct Fuel Injection........................................................................... 161

6.5.3. Oil-Less Operation.............................................................................. 164

6.5.4. Alternative Fuels................................................................................. 166

6.5.5. Homogeneous Charge Compression Ignition.................................... 167

6.6. Early Empirical Design................................................................................ 1696.6.1. Overall Engine Design........................................................................ 170

6.6.2. Kinematic Design................................................................................ 1716.6.3. Cylinder Head, Cylinder, and Scavenging Chamber Design.............. 174

6.6.4. Piston and Seal Design........................................................................ 178

6.6.5. Fuel Supply System............................................................................ 180

6.6.6. Engine Testing.................................................................................... 1816.7. Concept Iteration and Refinements....... ..................................................... 185

6.8. Chapter Review............................................................................................ 186

Chapter 7: Conclusions................................................................................................... 189

7.1. Research Review and Summary....................................................................189

7.2. Results and Contributions............................................................................ 192

7.3. Recommendations and Further Work.......................................................... 194

7.4. A Personal Note........................................................................................... 196

References....................................................................................................................... 197

Bibliography....................................................................................................................208

Appendices......................................................................................................................209

LIST OF FIGURES

Figure 1.1: Project Timeline..............................................................................................7

Figure 2.1: Product Development Process.......................................................................14

Figure 2.2: Uncertainty Matrix........................................................................................19

Figure 2.3: Taxonomy of Product Strategies.................................................................. 20

Figure 2.4: Stage-Gate Process....................................................................................... 22

Figure 2.5: Overlapping Stage-Gate Process.................................................................. 25

Figure 2.6: Functional Interactions of Concurrent Engineering.....................................26

Figure 2.7: Typical PERT Chart..................................................................................... 28

Figure 2.8: Organisational Structure............................................................................... 29

Figure 2.9: Modes of Communication............................................................................ 33

Figure 3.1: Committed & Incurred Cost During Design................................................ 39

Figure 3.2: Framework of Axiomatic Design....................................................... 42

Figure 3.3: Model of Systematic Design........................................................................ 45

Figure 3.4: Pugh’s Total Design Activity Model............................................................ 47

Figure 3.5: TRIZ Problem Solving Model...................................................................... 49

Figure 3.6: WOIS - Overcoming the Spiral of Evolution.............................................. 51

Figure 4.1: A Model of the Fuzzy Front End.................................................................. 62

Figure 4.2: The Design Paradox..................................................................................... 63

Figure 4.3: Environment for Creativity........................................................................... 64

Figure 4.4: Innovative Conceptual Design Framework.................................................. 68

Figure 4.5: Technology Identification, Analysis, & Evaluation Chart........................... 73

Figure 4.6: The Black Box Model...................................................................................77

Figure 4.7: Functional Decomposition of the Oil-Less Two-Stroke Engine Problem.... 78

Figure 4.8: Objectives Tree for the Oil-Less Two-Stroke Engine.................................. 80

Figure 4.9: House of Quality............................................................................................81

Figure 4.10: Hierarchical Structure of Engine Functions.............................................. 85

Figure 4.11: Morphological Chart for the Oil-Less Two-Stroke Engine....................... 93

Figure 4.12: Evaluation Chart for the Oil-Less Two-Stroke Engine.............................98

Figure 4.13: Weighted Values Assigned to the Objectives Tree from Figure 4.8.........99

Figure 4.14: Pugh's Evaluation Matrix for the Oil-Less Two-Stroke Engine............. 101

Figure Page

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Figure 4.15: Factors Influencing the Decision-Making Process....................................103

Figure 4.16: Concept Classification & Evaluation Scheme...........................................105

Figure 5.1: TICS Focus Model...................................................................................... 112

Figure 5.2: Product Cost Management..........................................................................131

Figure 5.3: Example of Function Sharing......................................................................137

Figure 6.1: Typical Configuration of a Two-Stroke Engine..........................................148

Figure 6.2: P-V Diagram of the Two-Stroke Cycle.......................................................149

Figure 6.3: Scavenging Arrangements........................................................................... 150

Figure 6.4: Typical Sequence of Two-Stroke Cycle Events..........................................152

Figure 6.5: Test Engine Model.....................................................................................170

Figure 6.6: Real Test Engine.......................................................................................... 171

Figure 6.7: Exhaust Valve Actuation Mechanism.........................................................175

Figure 6.8: Cylinder Head (Outside View)....................................................................176

Figure 6.9: Cylinder Head (Internal View)....................................................................176

Figure 6.10: Cylinder..................................................................................................... 177

Figure 6.11: Scavenging Chamber with Air-Inlet. Reed Valve. & Seal Package........177

Figure 6.12: Cylinder Assembly....................................................................................178

Figure 6.13: Piston with Piston Rings, Guide Ring, Piston Rod, & Rod End.............. 179

Figure 6.14: Flywheel with Magnet & Hall-Effect Sensors for Injection & Ignition... 180

Figure 6.15: Control Board............................................................................................ 181

Figure 6.16: Dynamometer............................................................................................ 182

Figure 6.17: Leakage Test.............................................................................................. 183

Figure 6.18: Initial Piston Ring & Modified Ring Design.............................................184

Figure 6.19: ICD Framework Applied to Case Study....................................................187

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LIST OF TABLES

Table 2.1: Reasons for New Innovative Products............................................................10

Table 2.2 Strategies of Innovative Product Development.............................................. 20

Table 2.3: Classification of Design................................................................................. 21

Table 3.1: Corollaries of Axiomatic Design................................................................... 43

Table 4.1: Identification of Need.....................................................................................69

Table 4.2: Market Analysis Methods...............................................................................71

Table 4.3: Market & Technology Data for Engine Concept........................................... 75

Table 4.4: Product Definition...........................................................................................76

Table 4.5: Determination of Product Attributes.............................................................. 83

Table 4.6: Engine Attributes............................................................................................86

Table 4.7: Rating Values for Some Specific Design Problems........................................89

Table 4.8: Concept Generation............................................ 90

Table 4.9: Concept Evaluation.........................................................................................97

Table 4.10: Five Point Evaluation Scale........................................................................100

Table 4.11: Concept Decision.......................................................................................103

Table 4.12: Maturity Scale............................................................................................. 106

Table 5.1: Classification of Costs.................................................................................129

Table 5.2: Value Engineering Aspects (adapted from Best 2000).................................132

Table 6.1: Case Study Procedures.................................................................................. 142

Table 6.2: Direct Fuel Injection Options........................................................................162

Table 6.3: Engine Mechanism Comparison..................................................................172

Table Page

GLOSSARY AND NOTATIONS

ACE Active Combustion Engine

AI Artificial Intelligence

ATAC Active Thermo-Atmosphere Combustion

BDC Bottom Dead Centre

CA Customer Attributes

CAD Computer Aided Design

CAE Computer Aided Engineering

CAM Computer Aided Manufacturing

CAPP Computer Aided Process Planning

CBR Case Based Reasoning

CCES Concept Classification and Evaluation Scheme

CE Concurrent Engineering

CFD Computational Fluid Dynamics

Cl Compression Ignition

CIM Computer Integrated Manufacturing

CL Complexity Level

CNG Compressed Natural Gas

CO Carbon Monoxide

C02 Carbon Dioxide

CPM Critical Path Method

DBD Decision Based Design

DCDI Determination of Critical Design Issues

DFA Design for Assembly or Design for Affordability

DFC Design for Cost

DFD Design for Disassembly

DFM Design for Manufacturing or Design for Maintenance

DFR Design for Recycling

DFS Design for Serviceability or Design for Simplicity

DFX Design for X

DI Direct Injection

DoE Design of Experiments

DP Design Parameters

DR Delivery Ratio

ECU Engine Control Unit

EED Early Empirical Design

EGR Exhaust Gas Recirculation

EPA Environmental Protection Agency (US)

EU European Union

FEA Finite Element Analysis

FR Functional Requirements

FSI Fuel Stratified Injection

GA Generic Algorithm

GDI Gasoline Direct Injection

HC Hydrocarbons

HCCI Homogeneous Charge Compression Ignition

1C Internal Combustion

ICD Innovative Conceptual Design

IDI Indirect Injection

LPG Liquefied Petroleum Gas

MADM Multiple Attribute Decision Making

ML Maturity Level

MODM Multiple Objective Decision Making

MON Motor Octane Number

NOx Nitrogen Oxides

NPD New Product Development

OCP Orbital Combustion Process

PA Problem Analogy

PC Problem Complexity

PEEK Polyetheretherketone

PERT Program Evaluation and Review Technique

PF Problem Familiarity

PDS Product Design Specification

PM Particulate Matter

PR Purity Ratio

PTFE Polytetrafluoroethylene

PV Process Variables

QFD Quality Function Deployment

R&D Research and Development

RC Relative Cost

RL Risk Level

RON Research Octane Number

RSM Response Surface Methodology

SI Spark Ignition

SiC Silicon Carbon

S02 Sulphur Dioxide

TDC Top Dead Centre

TIAE Technology Identification, Analysis, and Evaluation

TRIZ Teoriya Resheniya Izobreatatelskikh Zadatch (Theory of Inventive Problem Solving)

US United States

UTS University of Technology, Sydney

VA Value Analysis

VE Value Engineering

VDI Verein Deutscher Ingenieure

WOIS Widerspruchsorientierte Innovationsstrategie (Contradiction Oriented Innovation Strategy)

WOT Wide Open Throttle

SYMBOLS

B Cylinder Bore

S Piston Stroke

Sec Effective Compression Stroke

See Effective Expansion Stroke

a Crank Offset

rSb Stroke-to-Bore Ratio

Vd Displacement Volume

Vdec Effective Compression Displacement Volume

Vdee Effective Expansion Displacement Volume

Vc Clearance Volume

V, Total Cylinder Volume

Ap Piston Crown Surface Area

Ah Cylinder Head Surface Area

At Total Cylinder Surface Area

rc Compression Ratio

rgc Geometric Compression Ratio

rec Effective Compression Ratio

ree Effective Expansion Ratio

cp Crank Angle

Nc Rotational Speed of Crank

(oc Angular Velocity of Crank

vpm Mean Piston Velocity

nr Number of Crank Revolutions per Cycle

Pet Cylinder Pressure at TDC

pcs Cylinder Pressure after Scavenging

A/F Air/Fuel Ratio

m*a Mass Flow Rate of Air

m*/ Mass Flow Rate of Air

Qhv/ Lower Heating Value

Qa Heat Addition

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Zq, Cumulative Heat Release Fraction

n Weibe Form Factor

a Weibe Efficiency Factor

P Power Output

T Torque or Temperature

mep Mean Effective Pressure

imep Indicated Mean Effective Pressure

bmep Brake Mean Effective Pressure

fmep Friction Mean Effective Pressure

sfc Specific Fuel Consumption

Y\th Thermal Efficiency

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ABSTRACT

Innovative Product Design Conceptualization

with Oil-Less Two-Stroke Engine as a Case Study

Innovative product design is a creative process, involving extensive skills and

knowledge, numerous stakeholders with often conflicting interests, and a variety of

trade-off decisions. The multitude of different variables to be considered together with

the complex nature of engineering design confronts designers with a difficult challenge.

The objective of this thesis is to establish a methodology that will help to formalise and

enhance innovative conceptual product design. To achieve this, an oil-less two-stroke

engine concept has been taken as a case study in order to elaborate, demonstrate, and

validate the proposed Innovative Conceptual Design framework. The methodology aims

to yield design process insight and transparency, and embodies two major phases: the

Pre-Development activities, including the identification of need and product definition,

and the Conceptualization Loop, which comprises the determination of attributes,

concept generation, concept evaluation, and concept decision.

In this present research, the Determination of Critical Design Issues together with Early

Empirical Design are identified as two essential aspects of successful conceptual

design. Early detection of potential design problems is vital for making intelligent and

rapid concept decisions before significant development resources are committed. This

approach also allows critical design issues to be tackled first in order to avoid going

down blind alleys, and helps to control risk and cost.

The thesis presents the author’s view of conceptual design as involving a continuous

focus on four major pillars of design, namely the Time Focus, the Innovation Focus, the

Cost Focus, and the Simplicity Focus, the “TICS Focuses”. On the basis of this

perception the discrete design activities during the entire design process aim to develop

an innovative, inexpensive, and simple product that is introduced to the marketplace in a

timely manner. This may require the designer to make a number of compromises, which

can be facilitated by the early detection of design problems by means of Early Empirical

Design.

In essence, the suggested conceptual design framework supports design engineers in

making issues and problems obvious in the early, least-costly phases of product

development. This is the key to accelerating the overall design process and avoiding

product failures.

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