these.w.attard

Small Engine Performance Limits Turbocharging, Combustion or Design

William Attard

Submitted in total fulfillment of the requirements

of the degree of Doctor of Philosophy

2007

Department of Mechanical and Manufacturing Engineering

The University of Melbourne

Produced on archival quality paper

iii

You learn more from failure than success

v

Growing concerns about interruption to oil supply and oil shortages have led to

escalating global oil prices. In addition, increased public acceptance of the global

warming problem has prompted car manufacturers to agree to carbon emission

targets in many regions including most recently, the Californian standards. Other

legislating bodies are sure to follow this lead with increasingly stringent targets.

As a result of these issues, spark ignition engines in their current form will need

significant improvements to meet future requirements. One technically feasible

option is smaller capacity downsized engines with enhanced power that could be

used in the near term to reduce both carbon emissions and fuel consumption in

passenger vehicles.

This research focuses on exploring the performance limits of a 0.43 liter spark

ignited engine and defining its operating boundaries. Limiting factors such as

combustion, gas exchange and component design are investigated to determine if

they restrict small engine performance. The research gives direction to the

development of smaller gasoline engines and establishes the extent to which they

can contribute to future powertrain fuel consumption reduction whilst maintaining

engine power at European intermediate class requirements.

As no small OEM production engine could be adapted to evaluate this concept, a

four valve, inline two cylinder engine was designed and constructed to withstand

the high combustion and inertia forces associated with near two bar boost

pressure and engine speeds exceeding 10,000 rev/min. The asymmetric (odd) fire

configuration required the uneven flow conditions in the intake and exhaust

systems to be accommodated in the engine design to reliably achieve 25 bar

brake mean effective pressure. This is believed to be the highest recorded value

for a small spark ignition engine operating on pump gasoline. In addition, the test

engine achieved a maximum of 37% brake thermal efficiency.

Abstract P O W E R E D B Y W A T T A R D

vi

Best engine performance, efficiency and CO2 benefits across normally aspirated,

supercharged and turbocharged modes were found to match or exceed the

capabilities of typical larger bore engines found in passenger vehicles. The case

study performed determined the feasibility of replacing a 1.25 liter normally

aspirated engine found in the 2007 Ford Fiesta with the development engine in

the turbocharged mode. Results show that the power and hence acceleration

performance of the larger engine could be readily matched with the smaller

turbocharged unit, with a 66% reduction in engine capacity. Simulated

performance over the New European Drive Cycle showed a possible 22%

reduction in fuel consumption and CO2 emissions, including a reduction of 62% at

idle conditions. These benefits are a consequence of operating the test engine

closer to peak efficiency, together with engine and chassis mass reductions. The

reduction in CO2 would shift the study vehicle well under the 2012 Euro target of

120 g/km.

Across all modes, it was evident that the small test engine could operate with

considerably higher compression ratio for a given manifold absolute pressure

when compared to larger bore, lower speed engines. This was demonstrated with

normally aspirated results showing potential for engine operation at a compression

ratio exceeding 13. However, the dominant performance limiting factor was

experimentally found to be abnormal combustion, specifically knock in the end-gas

region, with the highest knock intensities deduced to occur on the intake side of

the pent roof combustion chamber.

Thus it is concluded that further efficiency gains are possible with higher octane

fuel, as the turbocharged engine was knock limited at a compression ratio of 10.

Extrapolation of the efficiency and maximum performance data for the

compression ratio range of 9 to 13 could aid a well-to-wheel study defining what

the optimum fuel octane number is, assuming that refinery energy requirements

are known for different octane fuels.

vii

I hereby declare that this thesis comprises only my original work towards the PhD,

except where indicated by reference and acknowledgment in the text. I further

certify that this thesis is less than 100,000 words, exclusive of tables, maps,

bibliographies and appendices.

William Attard

Declaration P O W E R E D B Y W A T T A R D

ix

After spending nearly a decade enrolled as a student at this university, the end

has finally come following many amazing and heartbreaking experiences.

Thinking back on how this project initially started six years ago, I would have

never imagined it could lead to a PhD. As an undergraduate student who had

taken two years study leave, I had aims of designing and constructing a specific

Formula SAE engine. It has been a life changing experience that has consumed

me and I am forever indebted to many people who contributed to the wellbeing of

myself and my work throughout this soul searching journey.

To my understanding family, my appreciation cannot be expressed in words to my

father, mother and brother who provided me with the opportunity to further my

education, supplying endless amounts of encouragement and instilling the belief

that I could succeed. They each supported me in different ways throughout this

journey. One cant forget my mothers excellent cooking, which always brought

me home even after traveling to many parts of the world. Thank you.

To my loving partner, Elisa Toulson, a lovely lady who I met in the

thermodynamics laboratory who reminded me that life does not revolve around

engines. Who would have thought spending so many hours in one place would

have paid off so handsomely. You have brought balance to my life and been the

most important aspect to come out of my time at university. I am struggling to

find words to describe all her efforts, but most importantly thank you for always

having time for me.

To my supervisor, mentor and friend, Professor Harry Watson, a great man whose

wealth of knowledge, many ideas and shear enthusiasm got me into and out of

trouble on many occasions. Who would have thought we would have come so far

together after that telephone call six years ago. Thanks for the opportunity and

your continual support. Truly a great man who cares.

Acknowledgements P O W E R E D B Y W A T T A R D

x

To fellow students Steve Konidaris and Mohammad Ali Khan, thank you for

spending many late nights and early mornings in the thermodynamics laboratory

testing engines, retrieving broken bits and solving problems, not all to do with the

engines. Your persistence and support during the most trying times of the engine

development phase has made both of you my two closest friends.

I am also grateful to academics, fellow students, friends and technical staff

involved in this project. There are many names to mention but I am especially

grateful to Dr Ferenc Hamori, Faisal Lodi, Phuong Pham, Mark Gledhill, Terry

Karagounis and George Zakis for their generous assistance and continual support

throughout various stages of my PhD. Additionally, I would like to thank Don

Halpin and Ted Grange for their technical assistance, good humor and on

occasion, turning a blind eye. Altogether, a great bunch of people to work with.

Lastly, to the numerous sponsors outlined in Appendix A whose generosity made

the UniMelb WATTARD engine possible, I offer my sincere thanks for supporting

the excellent learning activity at the University of Melbourne.

xi

Abstract v

Declaration vii

Acknowledgements ix

Table of Contents xi

List of Figures xxi

List of Tables xli

Nomenclature xlv

Chapter 1 - Introduction 1

1.1 Motivation for Research .............................................................................. 2

1.1.1 Initial Formula SAE Objectives ............................................................ 2

1.2 Research Objectives.................................................................................... 3

1.3 Outline of Thesis ........................................................................................ 3

Chapter 2 - Background and Review 7

2.1 Global Vehicle Trends ................................................................................. 7

2.2 Fuel Consumption....................................................................................... 9

2.3 CO2 Emissions and Global Warming ........................................................... 11

2.4 Spark Ignition versus Diesel Engines.......................................................... 14

2.5 Small Engines........................................................................................... 15

2.6 Turbocharging and Engine Downsizing....................................................... 16

2.7 Combustion.............................................................................................. 18

2.7.1 Abnormal Combustion......................................................................... 20

2.7.2 Knock Reduction Methods ................................................................... 21

2.8 Summary ................................................................................................. 21

Chapter 3 - Engine Design 23

3.1 Introduction ............................................................................................. 23

3.2 Design Brief ............................................................................................. 24

Contents P O W E R E D B Y W A T T A R D

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3.3 Theoretical Analysis .................................................................................. 24

3.3.1 Engine Capacity and Configuration ...................................................... 24

3.3.2 CFD Simulation................................................................................... 27

3.4 Achieving Balance in the Design Process .................................................... 30

3.4.1 The Feasibility of OEM Engine Adaption ............................................... 30

3.4.2 OEM Component Adaption .................................................................. 31

3.4.3 New Components ............................................................................... 34

3.5 Rotating and Reciprocating Assembly......................................................... 35

3.5.1 Load Analysis ..................................................................................... 35

3.5.2 Connecting Rod.................................................................................. 39

3.5.3 Piston Assembly ................................................................................. 44

3.5.4 Crankshaft ......................................................................................... 47

3.6 Cylinder Block Design ............................................................................... 50

3.6.1 Gasketless Interface Design ................................................................ 51

3.6.2 Torque Plate Design ........................................................................... 57

3.6.3 Thermal Analysis ................................................................................ 60

3.6.4 Manufactured Design.......................................................................... 67

3.7 Manifold Design........................................................................................ 67

3.8 Final Specifications and Assembly .............................................................. 73

3.9 Summary ................................................................................................. 73

Chapter 4 - Experimental Apparatus and Methodology 77

4.1 Introduction ............................................................................................. 77

4.2 Engine Test Rig ........................................................................................ 78

4.2.1 Dynamometer and Control Unit ........................................................... 81

4.2.2 Dynamometer-Engine Coupling ........................................................... 82

4.2.3 Engine Cradle..................................................................................... 83

4.2.4 Cooling system................................................................................... 83

4.2.5 Electrical System ................................................................................ 84

4.2.6 Exhaust System.................................................................................. 86

4.3 Instrumentation and Data Acquisition ........................................................ 87

4.3.1 Fuel and Air Flow Measurement........................................................... 87

4.3.2 Exhaust Emissions Analyzer ................................................................ 88

4.3.3 Blow-by Measurement ........................................................................ 88

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4.3.4 Cylinder Pressure Measurement........................................................... 89

4.3.5 Data Acquisition and Pre-Processing .................................................... 89

4.4 Experiments ............................................................................................. 92

4.4.1 Experimental Objectives...................................................................... 92

4.4.2 Experimental Results Analysis.............................................................. 92

4.5 Test Modes .............................................................................................. 93

4.6 Test Methodology .................................................................................... 98

4.6.1 Test Matrix......................................................................................... 98

4.6.2 Test Sequence ................................................................................... 99

4.6.3 Test Procedure..................................................................................101

4.6.4 Tuning Strategy.................................................................................102

4.7 Summary ................................................................................................103

Chapter 5 - Engine Development 105

5.1 Introduction ............................................................................................105

5.2 Barrel and Liner Gasketless Interface ........................................................108

5.2.1 Manufacturing and Assembly..............................................................108

5.2.2 Initial Testing ....................................................................................110

5.2.3 Failure Analysis and Rectification ........................................................110

5.2.4 Interface Performance .......................................................................113

5.3 Electrical System .....................................................................................114

5.3.1 Ignition System .................................................................................114

5.3.2 Reference and Synchronization Signals ...............................................115

5.4 Piston Assembly ......................................................................................117

5.4.1 Piston ...............................................................................................117

5.4.2 Piston Ring Pack................................................................................121

5.4.3 CR Variation ......................................................................................123

5.4.4 Piston Oil Cooling ..............................................................................124

5.4.5 Piston to Valve Clearance...................................................................126

5.4.6 Piston Skirt and Liner.........................................................................128

5.5 Inlet Manifold ..........................................................................................129

5.5.1 Reliability ..........................................................................................129

5.5.2 Fuel Injector Location ........................................................................131

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5.5.3 Intake Runner Geometry....................................................................135

5.6 Exhaust Manifold .....................................................................................137

5.7 Engine Balance and Vibration ...................................................................139

5.8 Camshaft and Timing Chain .....................................................................142

5.9 Summary ................................................................................................144

Chapter 6 - Turbocharging 147

6.1 Introduction ............................................................................................147

6.2 Turbocharger Selection ............................................................................148

6.3 Oil Control in Throttled Compressors.........................................................149

6.4 Turbocharger Development......................................................................151

6.4.1 Oil Control ........................................................................................152

6.4.2 Cooling .............................................................................................158

6.4.3 Intake Boost Regulation.....................................................................159

6.5 Turbocharger Performance Optimization ...................................................161

6.5.1 Exhaust Manifold Geometry ...............................................................162

6.5.2 Inlet Manifold Geometry ....................................................................169

6.5.3 Valve Timing - Camshaft Specification ................................................172

6.5.4 Final Results .....................................................................................178

6.6 Final Turbocharger Matched Operation .....................................................179

6.7 Summary ................................................................................................184

Chapter 7 - Operating Limits and Experimental Results 187

7.1 Introduction ............................................................................................187

7.2 Operating Limits ......................................................................................188

7.3 Contour Plot Generation...........................................................................196

7.4 Performance Contours .............................................................................198

7.4.1 BMEP................................................................................................198

7.4.2 Brake Power .....................................................................................200

7.4.3 Spark Timing.....................................................................................202

7.5 Efficiency Contours ..................................................................................204

7.5.1 Lambda ............................................................................................204

7.5.2 BSFC and Brake Thermal Efficiency ....................................................206

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7.5.3 Volumetric Efficiency..........................................................................210

7.5.4 Mechanical Efficiency .........................................................................212

7.6 Emissions Contours..................................................................................212

7.6.1 BSHC................................................................................................214

7.6.2 BSNOx ..............................................................................................219

7.6.3 BSCO2...............................................................................................222

7.6.4 BSCO................................................................................................226

7.7 Summary ................................................................................................228

Chapter 8 - Performance, Efficiency and Emission Comparisons 229

8.1 Introduction ............................................................................................229

8.2 Carburetion and PFI Fuel Delivery.............................................................230

8.3 Intake Flow Restrictor Effects ...................................................................232

8.4 NA, SC and TC Mode Comparisons............................................................238

8.5 Comparison to FSAE Engines ....................................................................243

8.6 Comparison to Small Engines ...................................................................246

8.7 Comparison to Larger Bore Engines ..........................................................248

8.8 Extension to a Future Application - Feasibility for a 1.25 Liter Replacement .251

8.8.1 Performance .....................................................................................253

8.8.2 Fuel Consumption and CO2 Emissions .................................................255

8.9 Summary ................................................................................................260

Chapter 9 - Combustion Analysis 263

9.1 Introduction ............................................................................................263

9.2 Combustion in Small Engines....................................................................264

9.3 Data Post Processing ...............................................................................264

9.3.1 E-CoBRA ...........................................................................................266

9.4 NA Combustion........................................................................................268

9.5 TC Combustion........................................................................................276

9.5.1 Ignition Energy..................................................................................284

9.6 Knock .....................................................................................................288

9.6.1 Knock Location..................................................................................289

9.6.2 Implemented Knock Control Strategies ...............................................293

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9.6.3 Observations of Knocking Combustion ................................................293

9.7 Discussion...............................................................................................299

9.7.1 Comparison of Small versus Large Bore Combustion............................299

9.7.2 Further Suggested Knock Control Strategies........................................302

9.8 Summary ................................................................................................305

Chapter 10 - Conclusions 307

10.1 Introduction ..........................................................................................307

10.2 Research Achievements .........................................................................308

10.2.1 Mechanical Design and Development ................................................308

10.2.2 Experiments ....................................................................................310

10.2.3 Formula SAE ...................................................................................312

10.3 Conclusions to the Research...................................................................312

10.4 Recommendations for Future Work.........................................................315

10.4.1 Implementation into a Passenger Vehicle ..........................................317

Awards and Publications 319

References 321

Appendix 347

A - Sponsor Acknowledgments 347

B - Formula SAE 349

B.1 Introduction............................................................................................349

B.2 What is FSAE?.........................................................................................349

B.3 Engine Rules and Regulations ..................................................................351

B.4 Improving Engine Performance ................................................................352

B.4.1 Specific Output .................................................................................352

B.4.2 Packaging.........................................................................................352

B.5 Review of Past Formula SAE Engines ........................................................353

B.6 New Engine Targets for Formula SAE .......................................................356

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C - Fuel Properties and Emission Regulations 357

C.1 Fuel Properties ........................................................................................357

C.2 Emission Regulations ...............................................................................359

D - Restrictor Calculations 361

D.1 Maximum Theoretical Restrictor Mass Flow Rate .......................................361

D.2 Flow Through a Venturi ...........................................................................362

D.3 Compressible Flow Intake Model ..............................................................363

D.4 Pre-Restrictor Fuel Injection.....................................................................363

D.4.1 Restricted Mass Flow.........................................................................363

D.4.2 Manifold Air Temperature ..................................................................365

D.5 Maximum Power .....................................................................................366

E - Turbocharger Selection 367

E.1 Introduction ............................................................................................367

E.2 Aspect ....................................................................................................368

E.2.1 Availability and Cost ..........................................................................368

E.2.2 Matching...........................................................................................368

E.2.3 Implementation.................................................................................373

E.2.4 Control .............................................................................................373

E.2.5 Mass and Packaging ..........................................................................375

E.2.6 Cooling and Lubrication .....................................................................375

E.2.7 Final Selection...................................................................................375

F - Engine CFD Simulation 377

F.1 Introduction ............................................................................................377

F.2 Ricardo WAVE Models ...........................................................................378

F.2.1 Cylinder Model ..................................................................................378

F.2.2 Pipe Model ........................................................................................379

F.2.3 Complex Pipe Junction Model .............................................................380

F.2.4 Turbocharger Model...........................................................................381

F.2.5 Turbocharger Wastegate Control Model ..............................................381

F.2.6 Muffler Model ....................................................................................383

F.2.7 Friction Model....................................................................................383

xviii

G - Transmission Ratio Optimization 385

G.1 Gear Ratio Optimization...........................................................................385

G.2 Final Matched Transmission .....................................................................386

H - Flow Bench Airflow Testing 389

H.1 Introduction............................................................................................389

H.2 Steady versus Pulsating Flow ...................................................................390

H.3 Super-Flow SF600 Flow Bench .................................................................390

H.4 Flow Test Rig and Experiments ................................................................392

H.5 Flow Test Results ....................................................................................393

H.5.1 Cylinder Head Mass Flow...................................................................394

H.5.2 Cylinder Head Discharge Coefficients .................................................395

H.5.3 Engine Discharge Coefficients ............................................................396

H.5.4 Intake Restrictor Nozzle Mass Flow ....................................................397

I - Engine Subsystem and Transmission Development 399

I.1 Introduction.............................................................................................399

I.2 Clutch Assembly.......................................................................................400

I.3 Transmission ...........................................................................................404

I.4 Lubrication System...................................................................................405

I.5 Water Cooling System ..............................................................................410

J - Test Rig Development and Calibration 413

J.1 Introduction ............................................................................................413

J.2 Brake Torque Measurement and Calibration...............................................414

J.3 Dynamometer-Engine Coupling Development and Calibration .....................415

J.4 Fuel Measurement and Calibration ............................................................419

J.5 Blow-by Measurement and Calibration.......................................................420

J.6 Cooling System Calibration .......................................................................421

J.7 Cylinder Pressure Measurement and Calibration .........................................422

J.8 TDC Alignment ........................................................................................425

J.9 Compression Ratio Calibration ..................................................................426

xix

K - Piston Repair 429

K.1 Piston Repair Techniques .........................................................................429

L - Engine Run-In 431

L.1 Engine Run-In Procedure .........................................................................431

M - Exhaust Gas Analysis 433

M.1 ADS-9000 Exhaust Gas Analyzer ..............................................................433

M.2 Exhaust Gas Sampling Position ................................................................434

M.3 ADS-9000 Emission Correction.................................................................436

M.3.1 Eliminating Air Leakage .....................................................................436

M.3.2 Correcting for Hydrocarbon Type .......................................................436

M.3.3 Hydrocarbon Sensitivity.....................................................................437

M.3.4 Wet/Dry Analysis and Compensation..................................................437

M.4 AFR Calculation.......................................................................................438

M.4.1 Calculation from Air and Fuel Measurement........................................438

M.4.2 Oxygen Measurement .......................................................................438

M.4.3 Calculation from the Exhaust Products ...............................................439

M.5 Brake Specific Emissions Calculation.........................................................441

M.6 AFR Variation..........................................................................................441

M.6.1 Efficiency Correction to Alternate ....................................................441

M.6.2 Emissions Correction to Alternate ....................................................442

N - Combustion Modeling 447

N.1 Introduction............................................................................................447

N.2 Model Outline..........................................................................................447

N.3 Engine Geometric Relationships ...............................................................449

N.4 Combustion Modeling ..............................................................................450

N.4.1 Residual Gas Mass Fraction................................................................450

N.4.2 Compression and Expansion Process ..................................................450

N.4.3 Combustion Process ..........................................................................452

N.5 Heat Transfer..........................................................................................454

N.6 Chemical Equilibrium ...............................................................................456

xx

N.6.1 Chemical Equilibrium Solver Accuracy.................................................463

N.7 Flame Geometry .....................................................................................463

N.8 Laminar and Turbulent Flames.................................................................465

N.8.1 Laminar Flame Speed........................................................................466

N.8.2 Actual Flame Speed...........................................................................467

N.8.3 Flame Speed Ratio ............................................................................468

N.8.4 Turbulence Intensity .........................................................................468

N.9 Knock Amplitude .....................................................................................469

O - Error Analysis 471

O.1 Measurement and Calculation Error..........................................................471

P - Drawing Registry 473

xxi

Figure 2.1: Current and projected trends in global motor vehicle registration, Year:

1945-2025 [1, 71, 237, 239]. ..................................................................... 7

Figure 2.2: World motor vehicle population per 1000 persons (1994 and 2005)

[231, 240]................................................................................................. 8

Figure 2.3: Chinese motor vehicle population showing the rapid growth since

1990. Vehicles exclude the ~50 million motorcycles and ~20 million

agricultural vehicles [237]. ......................................................................... 9

Figure 2.4: Crude oil prices and consumption heavily influenced by world events

[194]. ..................................................................................................... 10

Figure 2.5: US motor vehicle fuel economy, heavily influenced by oil prices [194,

233]. ...................................................................................................... 10

Figure 2.6: (Left): Share of greenhouse warming due to different greenhouse

gases [104]. (Right): Share of worldwide CO2 emissions from the combustion

of fuel, by sector [106]. ........................................................................... 11

Figure 2.7: Global mean temperatures (land and ocean) [165, 168]. ................ 12

Figure 2.8: Vehicle CO2 emissions. (Black): Fleet target averages over the NEDC

[46, 130]. (Blue): Alternative technologies. (Red): Californian regulations for

the FTP 75 cycle [61]............................................................................... 12

Figure 2.9: Large vehicle class technologies and the effects on cost and CO2

emissions [43]. (A6) six speed automatic transmission, (DCP) dual camshaft

phasing, (DCT) dual clutch six speed transmission, (DE-ACT) cylinder

deactivation, (DVVL) discrete variable valve lift, (EACC) electric accessories,

(EPS) electric power steering, (GDI-S) gasoline direct injection at

stoichiometric, (G-HCCI) gasoline homogenous charge compression ignition,

(HEV) hybrid electric vehicle, (HSDI) high speed diesel, (IA) improved

alternator, (ICP) inlet camshaft phasing, (ISG) integrated starter generator,

(TC) turbocharged. .................................................................................. 13

Figure 2.10: Cost benefit analysis for CO2 improvements over the NEDC using

various technologies in SI and diesel engines [130, 174]............................ 15

List of Figures P O W E R E D B Y W A T T A R D

xxii

Figure 2.11: The effects on CR and fuel consumption over the NEDC for NA and

various capacity TC downsized engines with equal power output in the same

test vehicle [174]. ................................................................................... 17

Figure 2.12: Normal and abnormal (heavy spark knock) combustion in the test

engine. TC - PFI, 7000 rev/min, 220 kPa MAP, CR = 11, 12 BTDC spark

timing, peak knock amplitude = 3 MPa. .................................................... 19

Figure 3.1: Predicted engine air consumption needed to maintain choked flow

operating conditions for varying swept capacities and operating conditions

with model validation from previous experimental results........................... 26

Figure 3.2: Simulation results for the proposed two cylinder TC design and the

Melbourne University FSAE teams previous engine (NA Suzuki GSX-R600),

with Suzuki experimental results used for model validation. Both engines flow

restricted. ............................................................................................... 28

Figure 3.3: Ricardo WAVE model block diagrams used to predict FSAE engine performance for the flow restricted condition. (Upper): NA Suzuki GSX-R600

model used for initial software validation. (Lower): Proposed highly TC

engine model created to explore the expected performance gains from engine

downsizing. ............................................................................................. 29

Figure 3.4: Rocker cover patterns and magnesium alloy casting....................... 35

Figure 3.5: Sectional view of the final engine design highlighting the rotating and

reciprocating components. ....................................................................... 36

Figure 3.6: Crankshaft crankpin loads caused by inertia (reciprocating component

movement) and gas pressure (combustion) forces at maximum operating

conditions. (Upper): Combustion dominated force at maximum BMEP.

(Lower): Inertia dominated force at maximum speed................................. 38

Figure 3.7: Evaluation of H and I section beam connecting rods. (Upper): Equal

mass CAD models with beam cross section detail. (Lower): FEM model

analysis comparing von Mises stress distribution with x 100 distorted profile

shown..................................................................................................... 40

Figure 3.8: FEM model analysis comparing von Mises stress distribution for both

connecting rod designs under bending loads (misalignment or abnormal

pressure forces) with x 10 distorted profile shown. .................................... 41

xxiii

Figure 3.9: Various combustion chamber geometries highlighting highest loading

locations due to abnormal pressure forces (spark knock) thus favoring various

connecting rod designs to minimize deflection and ensure bearing reliability.

.............................................................................................................. 41

Figure 3.10: (Left): I section connecting rods during the manufacturing process.

(Right): Manufactured items to specified designs and drawings. ................. 42

Figure 3.11: FEM model analysis comparing von Mises stress distribution for

various connecting rod little-end oil hole locations (30 kN tensile load). (Left):

Single central hole in high loaded region and resultant stress concentration.

(Right): Two smaller holes. ...................................................................... 43

Figure 3.12: The design and manufacture of forged aluminum custom pistons

were required due to the high boost levels employed. (Left): Off-the-shelf

forged piston blank prior to machining. (Right): Manufactured piston design

with single compression ring. ................................................................... 44

Figure 3.13: FEM model piston analysis comparing von Mises stress distribution

for various gudgeon pin designs. .............................................................. 46

Figure 3.14: FEM crankshaft evaluation with bending and torsional loads. Note

the higher stresses in the second cylinders crankpin due to the transmission

drive path. .............................................................................................. 48

Figure 3.15: Manufactured crankshaft version. (Left): Original design. (Right):

Altered crankshaft design as detailed in Chapter 5.7. ................................. 50

Figure 3.16: Section view highlighting the cylinder block assembly (barrel and

liner) featuring the gasketless sealing arrangement with the cylinder head not

installed. ................................................................................................. 54

Figure 3.17: Assembled section view highlighting the cylinder block assembly

(barrel and liner) sealing arrangement. The cylinder head causes the barrel

to elastically distort, thus creating a robust seal......................................... 56

Figure 3.18: FEM model analysis simulating cylinder head loading on the barrel

and liner assembly. (Left): Von Mises stress distribution. (Right): Resultant

displacement. .......................................................................................... 57

Figure 3.19: Cylinder head stiffness measurement, needed for torque plate

design. (Left): Schematic highlighting loaded locations (F) and deflections

(D). (Right): Physical testing performed. ................................................... 58

xxiv

Figure 3.20: Results from load deflection tests performed on the cylinder head to

determine the relative cylinder head stiffness needed for the torque plate

design. ................................................................................................... 59

Figure 3.21: FEM model analysis simulating torque plate effects to determine

the thickness needed to represent the cylinder head. (Left): Vertical

displacement. (Right): Vertical displacement along section A-A. ................. 60

Figure 3.22: and CAD models used in the thermal FEM analysis, also

highlighting the division of the cylinder bore into five thermal regions. ....... 61

Figure 3.23: Temperature distribution on the combustion surface for the

model, indicating that the adiabatic assumption through the intake exhaust

plane can be assumed for the model. ................................................... 64

Figure 3.24: Cylinder head surface temperatures at peak combustion pressure

along the symmetry plane line for the model. The area highlighted

indicates the reduced temperature due to the gasketless interface. ............ 65

Figure 3.25: Liner surface temperatures at peak combustion pressure along the

symmetry plane line on the exhaust side for the model. ........................ 65

Figure 3.26: Cylinder head surface temperatures for peak combustion pressure

and exhaust blowdown models along the planes defining the model. ..... 66

Figure 3.27: (Left): Manufactured aluminum cylinder barrel. (Right): Barrel with

shrink fitted cast iron liners ready for engine installation. ........................... 67

Figure 3.28: (Left): Conventional plenum design. (Right): Watsons KEC log style

rolling flow design where the kinetic energy of the flow is conserved in a

vortex about the axis of the plenum. ........................................................ 68

Figure 3.29: Experimental data from a NA racing engine showing the effect of

engine speed on the dynamic pressure waves in the inlet tract @ WOT [102].

.............................................................................................................. 69

Figure 3.30: Effective inlet tract lengths created from a wave propagation

theoretical model highlighting the tuned engine speed for peak primary and

secondary resonance at varying ambient conditions................................... 69

Figure 3.31: (Left): Measured, inspected and cleaned components prior to

assembly. (Right): First complete engine assembly prior to dynamometer

installation. ............................................................................................. 72

Figure 4.1: Final version of the developed experimental rig. (Upper): Control

panel. (Lower): Experimental rig testing facility. ........................................ 79

xxv

Figure 4.2: Experimental setup illustrating the basic schematic layout of the

engine, including controllers, sensors and data acquisition systems. ........... 80

Figure 4.3: Heenan and Froude Dynamatic MK-1 eddy current dynamometer and

OZY-DYN type MISD109-01 control system. .............................................. 81

Figure 4.4: Engine cradle used to mount and locate the test engine to the

dynamometer. (Left): CAD image. (Right): Fabricated cradle frame, housing

the test engine. ....................................................................................... 83

Figure 4.5: Schematic layout of the fuel mass measurement system, calibrated to

provide fuel consumption rates................................................................. 87

Figure 4.6: Motoring raw cylinder pressure with crankshaft angle encoding from

WaveView. Time versus voltage, NA - PFI, 6000 rev/min, WOT, CR = 10.... 91

Figure 4.7: CAD and actual NA modes with fuel delivery variation. (Upper): Mode

A - NA with Carburetion (single carburetor shown in CAE model). (Lower):

Mode B - NA with PFI............................................................................... 94

Figure 4.8: Externally driven Roots type supercharger assembly. Mode C - SC

with PFI. ................................................................................................. 96

Figure 4.9: Mode D - TC with PFI, CAD model and final developed version. ....... 97

Figure 5.1: Test engine fitted into Melbourne University FSAE vehicles for further

engine development, testing and validation. (Upper): 2003 vehicle. (Lower):

2004 vehicle...........................................................................................106

Figure 5.2: FEM model analysis simulating the H7-p6 shrink fit between the

barrel and liner. (Left): Von Mises stress distribution. (Right): Resultant

displacement. .........................................................................................109

Figure 5.3: FEM model analysis simulating both the shrink fit and torque plate

effects. (Left): Von Mises stress distribution. (Right): Resultant

displacement. .........................................................................................109

Figure 5.4: Failed gasketless interface with clear signs of leakage between the

cylinder head and liner mating surfaces. High piston ring leakage is also

evident. .................................................................................................110

Figure 5.5: FEM model analysis simulating the gasketless interface effects on

the cylinder head. (Upper): Von Mises stress distribution. (Lower): Vertical

displacement. .........................................................................................112

xxvi

Figure 5.6: Crankshaft synchronization trigger edge (slot) development needed

for high speed operation due to the higher torsional and cyclic velocity

fluctuations associated with an odd firing twin configuration. ....................116

Figure 5.7: Effect of varying the number of compression rings (heat flux and oil

control effects) and fuel quality on combustion. TC - PFI, 7000 rev/min, 200

kPa MAP, CR = 10, 12 BTDC spark timing. .............................................120

Figure 5.8: CR variations ranging from 13-9.6 through piston crown modifications.

.............................................................................................................123

Figure 5.9: The effects due to a significant increase in underside oil cooling on the

single compression ring piston design (Type A). Disassembly after ~5 hours

operation at similar conditions. (Left): Dry crown. (Right): Chamber

contamination with oil pooling and deposits. ............................................124

Figure 5.10: The effects of insufficient piston to valve clearances. (Upper): Poppet

valve piston contact in individual cylinders. (Lower): Subsequent engine

damage as a result of valve failure in Cylinder 2. ......................................127

Figure 5.11: Piston skirt and liner damage during engine development.............129

Figure 5.12: Fatigue crack repairs and continued failures in the lightweight

aluminum alloy manifold discovered during development. .........................130

Figure 5.13: Initial polymer and final aluminum alloy inlet manifold versions....131

Figure 5.14: Intake manifold section highlighting the two differing injector setup

positions used during development..........................................................132

Figure 5.15: Fuel mixtures at associated MAP, TP and engine speed during

transient vehicle testing for the high injector configuration (Setup 2) depicted

in Figure 5.14. Note the fuel mixture excursion from lean to rich on

accelerator tip in, caused by fuel wall wetting due to the long mixing length.

.............................................................................................................133

Figure 5.16: Varying trumpet geometry highlighting the actual and effective

length, governed by the defined trumpet parameters (parameter A is a

constant). ..............................................................................................135

Figure 5.17: (Upper): Constructed short and long runner intake manifolds.

(Lower): Short and long runner engine air consumption comparison over

theoretical, CFD and experimental testing. TC - PFI, 4000 rev/min, WOT..136

xxvii

Figure 5.18: Exhaust manifold development due to the higher thermal and cyclic

mechanical stresses at the outlet junction due to turbocharger installation.

(Upper): Reliability concerns due to manifold cracking. (Lower): Thermal

loads from experiments and FEM analysis highlighting plenum chamber stress

concentrations due to vibration. ..............................................................138

Figure 5.19: (Left): Final constructed exhaust plenum design. (Right): FEM

analysis resulting in a fourfold reduction in mechanical stresses when

compared to the previous design in Figure 5.18 - Lower. ..........................139

Figure 5.20: Varying counterweight geometry designs used to alter the rotating

and reciprocation balance proportions for differing crankshafts used in

experiments. ..........................................................................................140

Figure 5.21: Failed crankshaft (Left): Heavy metal insert movement. (Right):

FEM failure analysis (von Mises stress distribution) simulating the interference

fit and the resulting plastic deformation in the alloy steel crank cheek. ......141

Figure 5.22: Engine damage caused by camshaft thrust bearing failure. ...........142

Figure 5.23: Consequences of negligence during the hard anodizing process with

the eroding of both cast iron cylinder liners with close-up detail. ...............143

Figure 6.1: Test engine turbocharger layout and resulting upstream compressor

throttling due to the mandatory throttle location and fitment of the intake

restrictor. ...............................................................................................149

Figure 6.2: Sectional view of the Garrett supplied GT-12 turbocharger with the

compressor and turbine housings removed. (Note): Water cooling jacket

detail altered and oil feed relocated for illustrative purposes only. .............151

Figure 6.3: Schematic displaying the failed oil control strategy (Table 6.2:

Strategy 3) to combat compressor throttled problems. Strategy involves

creating a pressure balance across the sealing system. .............................153

Figure 6.4: (Upper): Sectional view of the Garrett supplied GT-12 turbocharger.

(Lower): Sectional view of the redesigned turbocharger to overcome oil

consumption problems under throttled conditions. Note: Water cooling jacket

detail removed and oil feed relocated for illustrative purposes only............155

Figure 6.5: Strategy 10 - Components used to overcome the oil control issue.

(Upper): Modified centre bearing housing with silver soldered insert and

orifice vent. (Lower): Rotating assembly with new compressor seal assembly.

.............................................................................................................157

xxviii

Figure 6.6: Boost control schematic highlighting how the raw MAP signal was

manipulated by the ECU. This enabled the wastegate movement to be ECU

controlled to achieve the desired boost levels...........................................160

Figure 6.7: Simulated results displaying the performance discrepancies between

constant pressure and pulse type turbocharging for the flow restricted test

engine fitted with various exhaust manifold geometries. [ ] = Ease of

manufacture / 5. ....................................................................................163

Figure 6.8: Simulated pressure pulsations in the turbine housing when applying

pulse type turbocharging (Model A) to the odd firing test engine. TC - PFI,

6000 rev/min, single engine cycle............................................................164

Figure 6.9: Simulated brake power results comparing firing interval (odd and

even) for constant pressure and pulse type turbocharging. .......................166

Figure 6.10: Varying exhaust manifold geometry. (Upper): Two into one pulse

system (Model A). (Lower): Watsons KEC constant pressure plenum system

(Model E). ..............................................................................................167

Figure 6.11: Experimental versus simulation BMEP results for constant pressure

and pulse type turbocharging. TC - PFI, WOT, CR = 10. ..........................168

Figure 6.12: Experimental BMEP and spark timing results versus MAP for constant

pressure and pulse type turbocharging. TC - PFI, 5000 rev/min, CR = 10. 168

Figure 6.13: Simulated results showing cylinder airflow variations for TC operation

with varying intake volumes due to varying plenum chamber sizes. Airflow

variations associated with charge robbing effects caused by the flow

restriction and odd firing interval. ............................................................169

Figure 6.14: Experimental individual cylinder VOL and cylinder variations versus simulated results. Variations due to the charge robbing effects associated

with the flow restriction and odd firing interval. TC - PFI, CR = 10, 6 L intake

volume. .................................................................................................170

Figure 6.15: Experimental TC intake manifold air temperatures for various engine

speeds and MAP. Results highlight the possibility of not intercooling the

boosted charge for small engines if matched correctly. .............................171

Figure 6.16: Test engine simulated brake power results (WOT) with varying valve

overlap for constant pressure type turbocharging. (Upper): 0.7 L exhaust

volume. (Lower): 1.5 L exhaust volume. .................................................174

xxix

Figure 6.17: Test engine simulated brake power results (WOT) with varying IVC

timing for constant pressure type turbocharging. 2 L exhaust volume. ......175

Figure 6.18: Test engine simulated brake power results (WOT) with varying EVO

timing for constant pressure type turbocharging. 2 L exhaust volume. ......176

Figure 6.19: Comparison of experimental and predicted engine performance for

the test engine operating in the TC mode. ...............................................178

Figure 6.20: Garrett GT-12 compressor map with engine operating points overlaid

for varying engine speeds and MAP. ........................................................180

Figure 6.21: Garrett GT-12 turbine map with engine operating points overlaid for

varying engine speeds and MAP. .............................................................181

Figure 6.22: Intake and exhaust pressures and the effects on engine pumping

work for varying engine speeds. (Upper): PMEP. (Middle): Exhaust pressure.

(Lower): Log pressure-volume, highlighting the PMEP reduction for rising MAP

at 6000 rev/min......................................................................................182

Figure 7.1: NA mode knock limitations versus engine speed, MAP and CR. Cross

hatched areas indicate operation with spark retard to compensate for knock.

PL is the performance limit line defined at each modes WOT for a given CR.

(Left): Engine speed versus MAP domain. (Right): CR versus engine speed

domain. (Upper): NA - Carburetion. (Lower): NA - PFI. ...........................190

Figure 7.2: Boosted mode knock and airflow limitations versus engine speed, MAP

and CR. Cross hatched areas indicate operation with spark retard and/or fuel

enrichment to compensate for knock. Shaded areas indicate non-operation

due to knock levels above the DL or limited airflow. PL is the performance

limit line defined at each modes WOT for a given CR. (Left): Engine speed

versus MAP domain. (Right): CR versus engine speed domain. (Upper): SC -

PFI. (Lower): TC - PFI............................................................................192

Figure 7.3: TC - PFI mode (boost controlled) knock and airflow limitations versus

engine speed, MAP and CR. Cross hatched areas indicate operation with

spark retard and/or fuel enrichment to compensate for knock. Shaded areas

indicate non-operation due to knock levels above the DL or limited airflow. PL

is the performance limit line defined at each modes WOT for a given CR.

(Left): Engine speed versus MAP domain. (Right): CR versus engine speed

domain. (Upper): 200 kPa MAP limited. (Lower): 150 kPa MAP limited.....194

xxx

Figure 7.4: BMEP trends versus engine speed, MAP and CR. Shaded areas

indicate airflow limited regions. PL is the performance limit line. (Upper): NA

- Carburetion. (Middle): NA - PFI. (Lower Left): SC - PFI. (Lower Right): TC -

PFI. .......................................................................................................199

Figure 7.5: Brake Power trends versus engine speed, MAP and CR. Shaded areas



PFI. .......................................................................................................201

Figure 7.6: Spark timing trends versus engine speed, MAP and CR. Shaded areas



PFI. .......................................................................................................203

Figure 7.7: fueling requirements versus engine speed, MAP and CR. Shaded

areas indicate airflow limited regions. PL is the performance limit line.

(Upper): NA - Carburetion. (Middle): NA - PFI. (Lower Left): SC - PFI.

(Lower Right): TC - PFI...........................................................................205

Figure 7.8: BSFC trends versus engine speed, MAP and CR. Shaded areas indicate

airflow limited regions. PL is the performance limit line. (Upper): NA -

Carburetion. (Middle): NA - PFI. (Lower Left): SC - PFI. (Lower Right): TC -

PFI. .......................................................................................................207

Figure 7.9: Corrected BSFC trends ( = 1) versus engine speed, MAP and CR.

Shaded areas indicate airflow limited regions. PL is the performance limit

line. (Upper): NA - Carburetion. (Middle): NA - PFI. (Lower Left): SC - PFI.


Figure 7.10: VOL trends versus engine speed, MAP and CR. Shaded areas indicate airflow limited regions. PL is the performance limit line. (Upper): NA


PFI. .......................................................................................................211

Figure 7.11: MECH and exhaust pressure versus engine speed and MAP. Shaded areas indicate airflow limited regions. PL is the performance limit line. TC -

PFI, CR = 10. .........................................................................................212

Figure 7.12: Engine-out raw emission concentrations for varying and power

outputs, achieved with engine speed and MAP variation. TC - PFI, CR = 10.

.............................................................................................................213

xxxi

Figure 7.13: BSHC trends versus engine speed, MAP and CR. Shaded areas



PFI. .......................................................................................................215

Figure 7.14: Corrected BSHC trends ( = 1) versus engine speed, MAP and CR.




Figure 7.15: BSNOX trends versus engine speed, MAP and CR. Shaded areas


- Carburetion. (Lower Left): SC - PFI. (Lower Right): TC - PFI. .................219

Figure 7.16: Engine-out NOX emission concentrations for varying and power

outputs, achieved with engine speed, MAP and CR variation. (Upper): NA -

Carburetion: MAP = 100 kPa. (Middle): NA - Carburetion: CR = 13. (Lower):

SC - PFI: CR = 11...................................................................................221

Figure 7.17: BSCO2 trends versus engine speed, MAP and CR. Shaded areas



PFI. .......................................................................................................223

Figure 7.18: Corrected BSCO2 trends ( = 1) versus engine speed, MAP and CR.




Figure 7.19: Corrected BSCO2 trends ( = 0.9) versus engine speed, MAP and CR.




Figure 7.20: Mole fraction CO trends for varied and brake power (engine speed

and MAP variations). Shaded areas indicate unexplored regions. (Left): SC -

PFI. (Right): TC - PFI..............................................................................226

Figure 7.21: BSCO trends versus engine speed, MAP and CR. Shaded areas



PFI. .......................................................................................................227

xxxii

Figure 8.1: Performance, efficiency and emission effects for alternative CRs and

fuel delivery (carburetion and air restricted PFI). NA, WOT, = 0.9 0.02,

MBT spark timing. (Upper): BMEP. (Middle): BSFC. (Lower): Engine-out HC

mole concentrations. ..............................................................................231

Figure 8.2: Performance effects for odd (0.43 L, inline twin, CR = 13) and even

(0.6 L, inline four, CR = ~12) fire configurations in restricted (NA - PFI) and

unrestricted (NA - CARBS) modes. WOT, MBT spark timing......................233

Figure 8.3: Air consumption effects for restricted (NA - PFI) and unrestricted (NA -

CARBS) modes. WOT, CR = 13, MBT spark timing. (Upper): Individual

cylinder VOL. (Middle): Engine air consumption and limitations. (Lower): Cylinder and mode airflow variations. ......................................................235

Figure 8.4: Predicted air consumption effects versus time at a given upstream

condition (x) for odd (0.43 L, inline twin) and even (0.6 L, inline four) fire

configurations in restricted and unrestricted modes. .................................236

Figure 8.5: Maximum MAP values achieved at the PL (WOT) across all test modes

at the experimental test CR closest to the HUCR. .....................................238

Figure 8.6: Performance comparisons at the PL (WOT) for all modes at the

experimental test CR closest to the HUCR. (Upper): BMEP. (Middle): Brake

Power. (Lower): Spark Timing. ................................................................240

Figure 8.7: Efficiency comparisons at the PL (WOT) for all modes at the

experimental test CR closest to the HUCR. (Upper): VOL. (Middle): BSFC. (Lower): BSFC and TH corrected to = 1................................................242

Figure 8.8: WOT performance comparisons for a variety of engines tested for

FSAE application. Tests conducted on the same dynamometer with engines

fitted with a 20 mm intake flow restriction. ............................................245

Figure 8.9: WOT performance comparisons for a variety of small engines tested

and compared to the test engine across NA and TC modes. Engine

specifications outlined in Table 8.3. .........................................................247

Figure 8.10: WOT performance comparison between the Ford Fiesta 1.25 L NA

engine and the smaller TC test engine used in experiments. (Upper): MAP.

(Middle): BMEP. (Lower): Brake Power. Two performance curves are shown

for the smaller test engine; (1) Limited MAP by wastegate (170 kPa), (2)

Limited airflow by a restriction (20 mm). ...............................................254

xxxiii

Figure 8.11: NEDC operating points for the Ford Fiesta chassis, used to compare

fuel consumption and CO2 emissions for the OEM 1.25 L engine and the

downsized 0.43 L test engine used in experiments. (Upper): Combined Urban

and Extra Urban drive cycle forming the NEDC [61]. (Lower): Generated time

frequency distribution for the NEDC [121]................................................257

Figure 9.1: Crankshaft effects at high engine speeds throughout one cycle. NA -

Carburetion, 10000 rev/min, WOT, CR = 10. (Upper): Velocity fluctuations.

(Middle): Torque fluctuations. (Lower): FEM analysis crankshaft elastic

deformation. ..........................................................................................265

Figure 9.2: The effects of re-sampling the raw pressure trace to 0.5 CA

increments, required for the E-CoBRA software input. TC - PFI, 7000 rev/min,

220 kPa MAP, CR = 11............................................................................267

Figure 9.3: Pressure-volume diagram for 40 consecutive cycles highlighting the

low combustion variability. NA - Carburetion, 10500 rev/min, WOT, CR = 13.

.............................................................................................................268

Figure 9.4: Combustion burn duration effects for alternative CRs and fuel delivery.

NA, WOT, = 0.9 0.02, MBT spark timing. (Upper): 0-10% MFB. (Middle):

10-90% MFB. (Lower): 0-90% MFB. Solid lines associated with CA axis,

dashed lines with time axis......................................................................269

Figure 9.5: Combustion burn effects for alternative CRs and fuel delivery. NA,

10000 rev/min, WOT, = 0.9 0.02, MBT spark timing [ ]. (Upper): MFB

versus CA. (Middle): MFB versus MFBR. (Lower): MFBR versus CA...........271

Figure 9.6: Estimated turbulence intensity u for alternative CRs and fuel delivery.

NA, WOT, = 0.9 0.02, MBT spark timing. ...........................................272

Figure 9.7: Combustion flame speed effects for alternative CRs and fuel delivery.

NA, WOT, = 0.9 0.02, MBT spark timing. (Upper): Actual flame speed @

50% MFB. (Middle): Actual flame speed ratio @ 50% MFB. (Lower): Actual

peak flame speed. ..................................................................................273

Figure 9.8: Combustion burn effects for varying engine speeds. NA - Carburetion,

WOT, CR = 10, = 0.9 0.02, MBT spark timing [ ]. (Upper): MFB versus CA

after Spark. (Middle): MFB versus MFBR. (Lower): MFBR versus CA.........275

xxxiv

Figure 9.9: Combustion variability and burn effects for varying engine speed and

MAP. TC - PFI, CR = 10. Shaded areas = airflow limited regions. Cross

hatched areas = knock compensated regions. PL = performance limit line at

WOT......................................................................................................277

Figure 9.10: Combustion burn effects for varying MAP. TC - PFI, 7000 rev/min,

CR = 10, spark timing [ ]. (Upper): MFB versus CA after Spark. (Middle):

MFB versus MFBR (solid lines - left y axis) and MBR (dashed lines - right y

axis). (Lower): MFBR versus CA. ............................................................279

Figure 9.11: Combustion pressure, temperature and flame speed effects for

varying engine speed and MAP. TC - PFI, CR = 10. Shaded areas = airflow

limited regions. Cross hatched areas = knock compensated regions. PL =

performance limit line at WOT.................................................................281

Figure 9.12: Combustion knock amplitude effects for varying engine speed and

MAP. TC - PFI, CR = 10. Shaded areas = airflow limited regions. Cross

hatched areas = knock compensated regions. PL = performance limit line at

WOT......................................................................................................282

Figure 9.13: Combustion effects @50% MFB for varying engine speed and MAP.

TC - PFI, CR = 10. Shaded areas = airflow limited regions. Cross hatched

areas = knock compensated regions. PL = performance limit line at WOT.283

Figure 9.14: Effect of varying ignition energies on boosted combustion over

consecutive tests. TC - PFI, 6000 rev/min, 160 kPa MAP, CR = 10, = 0.85

+/- 0.02.................................................................................................286

Figure 9.15: Effect of varying ignition energies on flame development over

consecutive tests. TC - PFI, 6000 rev/min, 160 kPa MAP, CR = 10, 17 - 18

BTDC spark timing..................................................................................287

Figure 9.16: Heavy knocking in the test engine well above the DL. TC - PFI, 7000

rev/min, 220 kPa MAP, CR = 11, 12 BTDC spark timing. Firing, motoring

and high pass filtered pressure traces......................................................289

Figure 9.17: Adverse effects of knock on engine components, with highest knock

intensities identified to occur in the end-gas on the intake side of the pent

roof combustion chamber. (Upper): Inlet side piston land failures. (Lower):

Cylinder head deck and piston erosion near the bore periphery on the inlet

side. ......................................................................................................291

xxxv

Figure 9.18: Cylinder head and piston crown surfaces after engine operation,

highlighting that the exhaust side is relatively hotter when compared to the

intake in four valve, pent roof combustion chambers. ...............................292

Figure 9.19: Simulation results from Teraji et al. [222] validating experimental

findings of the intake side being the most prone to high knock intensities.

Integral value is the knock predictor. .......................................................292

Figure 9.20: The effects of knock on in-cylinder pressures across 10 consecutive

cycles. TC - PFI, 7000 rev/min, 220 kPa MAP, 12 BTDC spark timing.

(Upper): Raw pressure. (Middle): Knock amplitude. (Lower): Smoothed log

pressure-volume.....................................................................................294

Figure 9.21: Varying knock intensities extracted from Figure 9.20. TC - PFI, 7000

rev/min, 220 kPa MAP, 12 BTDC spark timing. (Upper): Raw pressure.

(Middle): Knock amplitude - high pass filtered pressure. (Lower): Smoothed

pressure.................................................................................................295

Figure 9.22: Combustion burn effects for varying knock intensity cycles. TC - PFI,

7000 rev/min, 220 kPa MAP, 12 BTDC spark timing. (Upper): MFB versus

CA. (Middle): MFB versus MFBR. (Lower): MFBR versus CA. ....................296

Figure 9.23: Combustion burn effects for varying intensity knocking cycles. TC -

PFI, 7000 rev/min, 220 kPa MAP, 12 BTDC spark timing. (Upper): Actual

flame speed versus CA. (Lower): Actual flame speed ratio versus CA. .......298

Figure 9.24: Proposed pent roof design to reduce the intake side knock propensity

found from experiments. (Upper): Offset spark plug towards the intake side.

(Lower): Effect of ignition point on combustion burning profiles and

suggested knock location. .......................................................................303

Figure 10.1: The UniMelb WATTARD engine (TC - PFI mode) on display in the

foyer of Building 170, Mechanical Engineering at the University of Melbourne.

.............................................................................................................308

Figure B.1: International and local entries at the 2004 Australasian FSAE

competition. ...........................................................................................350

Figure B.2: Two extremes in FSAE engine selection. (Left): OEM Yamaha YZF

0.45 L single cylinder motocross engine. (Right): Western Washingtons

prototype 0.55 L V8. ...............................................................................355

xxxvi

Figure D.1: Subsonic, near sonic and supersonic flow for air ( = 1.4) in the divergent section of an intake venturi. (Upper): Pressure ratio (P/PO).

(Middle): Mach number (Ma). (Lower): Throat area ratio (A/A5) [245]. ......362

Figure E.1: Theoretical and assumed test engine air consumption needed to cause

choked flow through the intake restriction for varying engine speeds. .......369

Figure E.2: Turbocharger limits and corresponding compressor pressure ratio and

engine air consumption required to maintain choked flow over the desired

operating speed range. ...........................................................................370

Figure E.3: Garrett GT-15 compressor map with WOT engine operating points over

the choked operating speed range overlaid. .............................................371

Figure E.4: Garrett GT-15 turbine maps (VNT). ...............................................372

Figure E.5: Turbocharger exhaust turbine fitted with VNT technology highlighting

the vane position movement. ..................................................................373

Figure F.1: Garrett GT-12 maps generated using Ricardos TC-map. (Upper):

Compressor. (Lower): Turbine.................................................................382

Figure G.1: Engine vehicle matching through transmission design using the engine

performance data from Chapter 3.3.2. (Upper): 6-speed transmission for the

Suzuki GSX-R600 adapted to FSAE. (Lower): Optimized 3-speed transmission

for the test engine..................................................................................387

Figure H.1: SF600 flow bench schematic [213]. ..............................................391

Figure H.2: Orifice plate measurement detail for AS 2360.1.1-1993 and BS 1042

standards...............................................................................................391

Figure H.3: Experimental flow rig setup. ........................................................392

Figure H.4: Port experimental mass flow values at various test pressures.

Configurations A, B, and C correspond to various cylinder head and bore

combinations shown in Table H.1. (Upper): Inlet. (Lower): Exhaust. ........394

Figure H.5: Port discharge coefficients at various test pressures. Configurations

A, B, and C correspond to various cylinder head and bore combinations shown

in Table H.1. (Upper): Inlet. (Lower): Exhaust. .......................................395

Figure H.6: Engine discharge coefficients versus CA. Configurations A, B, and C

correspond to various cylinder head and bore combinations shown in Table

H.1. (Upper): Test pressure = 6 kPa. (Lower): Test pressure = 10 kPa.....396

xxxvii

Figure H.7: Intake restrictor experimental flow bench airflow data [78, 245].

Device A and B correspond to various Dall restrictor nozzle and diffuser

geometry outlined in Table H.2. (Upper): Mass flow rate. (Lower):

Discharge coefficient...............................................................................397

Figure I.1: FEM model analysis simulating varying spring loads applied to

various pressure plate designs after clutch slippage due to turbocharging.

Both pressure plate designs have similar mass and rotational inertia. (Left):

Von Mises stress distribution. (Right): Resultant displacement..................401

Figure I.2: FEM model analysis simulating the clutch basket at peak torque due to

turbocharging. (Left): Von Mises stress distribution. (Right): Resultant

displacement. (Top): Original basket. (Bottom): Developed version with

circumferential stiffening ring. .................................................................403

Figure I.3: Developed clutch housing enabling a twofold increase in torque

transmission in a confined space which was needed for boosted operation.404

Figure I.4: Transmission drive dog development needed for the high torque

output associated with intake boosting. ...................................................405

Figure I.5: Irreparable crankshaft and connecting rod damage as a result of oil

surge under high lateral vehicle acceleration, leading to big-end bearing

failure. ...................................................................................................406

Figure I.6: Dry sump oil path schematic, featuring internal oil and scavenge

pumps with an external oil pressure relief valve........................................408

Figure I.7: Brake performance effects for both wet and dry sump lubrication

systems. ................................................................................................409

Figure I.8: Initial inadequate turbocharger water cooling circuit, resulting in the

majority of flow bypassing the engine. .....................................................411

Figure J.1: Dynamometer torque calibration. (Upper): Methodology and

calculation. (Lower): Actual load cell calibration........................................414

Figure J.2: Brake torque calibration, beam calibration versus dynamometer

displayed. ..............................................................................................415

Figure J.3: Dynamometer coupling development. (Upper Left): Direct drive with

torsional damping. (Upper Right): 1st iteration - Counter levered shaft with

chain drive. (Lower Left): 2nd iteration - Chain drive with torsional dampening.

(Lower Right): 2nd iteration with chain tensioner.......................................417

xxxviii

Figure J.4: Brake torque measurement correction to compensate for the increased

losses associated with the chain drive when compared to the direct drive

system...................................................................................................417

Figure J.5: Dynamometer coupling development (Upper): Direct