UNIVERSITI PUTRA MALAYSIA

SIMULATION OF TRANSMISSION MATCHING TO IMPROVE CNG-DI VEHICLE PERFORMANCE

HAMZAH BIN ADLAN

FK 2007 13

SIMULATION OF TRANSMISSION MATCHING TO IMPROVE CNG-DI

VEHICLE PERFORMANCE

By

HAMZAH BIN ADLAN

Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia, in Fulfilment of the Requirement for the Degree of Master

of Science

January 2007

DEDICATION

Thank you to my wife, Natsue Hieda who is very patient with my

‘job’. Not to forget to my 2 lovely kids, Hana and Hadi who always give

me inspiration and ‘disturbance’ to complete the write-up. My parents who

always support whatever I am doing. My Rally Team mate who always

gives ideas on what I am doing. Lastly thank Almighty to give me strength

to finish this study.

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Abstract of thesis presented to the Senate of Universiti Putra Malaysia in fulfilment of the requirement for the degree of Master of Science

SIMULATION OF TRANSMISSION MATCHING TO IMPROVE

CNG-DI VEHICLE PERFORMANCE

By

HAMZAH BIN ADLAN

January 2007

Chairman: Professor Ir. Barkawi bin Sahari, Ph.D.

Faculty : Engineering

This research presents the process of designing a simulation tool to predict

dynamic performance of a vehicle. In this case, PROTON WAJA powered

by newly developed CNG-DI CamPro prototype engine was taken as

model to be predicted and at the same time to improve vehicle

performance. Besides that, the potentials of Natural Gas and Direct

Injection technology were reviewed as one of the main elements in this

project. However this paper will not cover the design change or

modification required to optimize Natural Gas as a fuel. Performance of

the CNG-DI engine was simulated to match with the five speed manual

transmission. In order to calculate the vehicle performance, combination of

gear ratio and final drive selection was carried out. Three gear ratios and

final drives combination were selected and compared. The best gear ratio

combined with best final drive will decide the best performance. Besides

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that, comparison between simulation result and actual test conducted by

vehicle manufacturer at the same test basis was also done to verify the

accuracy of simulation tool. The tool was design to ease engineers or

researchers when comes to transmission selection for a given vehicle.

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Abstrak tesis yang dikemukakan kepada Senat Universiti Putra Malaysia sebagai memenuhi keperluan untuk ijazah Master Sains

SIMULASI KESESUAIAN KOTAK GEAR UNTUK

MENINGKATKAN PRESTASI KENDERAAN CNG-DI

Oleh

HAMZAH BIN ADLAN

Januari 2007

Pengerusi: Profesor Ir. Barkawi Sahari, Ph.D.

Fakulti : Kejuruteraan

Penyelidikan ini mempersembahkan proses mereka bentuk sebuah

program simulasi untuk meramal prestasi sesebuah kenderaan. Dalam kes

ini, sebuah kereta PROTON WAJA yang dikuasai oleh injin CNG-DI yang

baru dibangunkan telah dipilih sebagai model untuk diramal disamping

ditingkatkan lagi prestasinya. Disamping itu, potensi Gas Asli (NG) dan

juga teknologi kaedah suntikan terus (DI) juga diulas sabagai sebahagian

elimen penting dalam penyelidikan ini. Walau bagaimanapun thesis ini

tidak menyentuh perihal perubahan rekabentuk atau modifikasi injin

untuk mengoptimumkan pengunaan Gas Asli. Prestasi injin CNG-DI telah

digunakan untuk dipadankan dengan kotak gear manual lima kelajuan.

Untuk mengira prestasi kenderaan, beberapa kombinasi nisbah gear dan

nisbah pacuan akhir telah dipilih dan dibuat perbandingan. Kombinasi

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nisbah gear dan nisbah pacuan akhir yang terbaik akan menentukan

prestasi kenderaan yang terbaik. Disamping itu, perbandingan diantara

keputusan simulasi dan keputusan ujian sebenar yang dijalankan oleh

pengeluar kereta mengunakan parameter yang sama telah dijalankan untuk

menguji ketepatan program simulasi. Program simulasi ini direka untuk

memudahkan para jurutera atau penyelidik untuk memadankan nisbah gear

terbaik untuk sesuatu kenderaan.

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ACKNOWLEDGEMENTS

I would like to express my gratitude to the chairman of the supervisory

committee Professor Ir. Dr. Barkawi Sahari for his advice and guidance

throughout the duration of the research. We had a lot of discussion

especially when two people had the same interest but coming from

different professional background. I would like also to thank Professor Dr.

Majeed Hamouda and Associate Professor Dr. Wong Sai Woon, whom

both acted as supervisory committee members. Not to forget to all staff,

Research Assistance and graduate student of Advance Automotive

Technology Lab (AATL, UPM) for their support and guidance.

I would also like to express thanks to Mr. Azahari and Mr. Zainul Hisham

of Powertrain Division who understand my load during this time. Further

appreciation to Mr. Zanudin and Mr. Ahmad Nazhrat from Powertrain

Division, who have supported me with valuable information.

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I certify that an Examination Committee met on 11th January 2007 to conduct the final examination of Hamzah bin Adlan on his Master of Science thesis entitled “SIMULATION OF TRANSMISSION MATCHING TO IMPROVE CNG-DI VEHICLE PERFORMANCE” in accordance with University Putra Malaysia (Higher Degree) Regulations 1981. The Committee recommends that candidate be awarded the relevant degree. Members of the Examination Committee are as follows:

Azmi b. Dato’ Yahya, PhD, Ir. Assoc. Professor Faculty of Engineering Universiti Putra Malaysia. (Chairman) Ir. Megat Mohamad Hamdan Megat Ahmad, PhD, Ir. Assoc. Professor Faculty of Engineering Universiti Putra Malaysia. (Member) Desa Ahmad, PhD, P.Eng, Ir. Professor Faculty of Engineering Universiti Putra Malaysia. (Member) Independent Examiner, Ph.D. Professor Faculty of Engineering University Malaya……. (Independent Examiner)

________________________________ HASANAH MOHD GHAZALI, PhD. Professor/Deputy Dean School of Graduate Studies Universiti Putra Malaysia

Date:

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This thesis submitted to the Senate of Universiti Putra Malaysia and has been accepted as fulfilment of the requirement for the degree of Master of Science. The members of the Supervisory Committee are as follows: Barkawi Sahari, Ph.D. Professor Faculty of Engineering Universiti Putra Malaysia (Chairman) Maged Hamouda, Ph.D. Professor Faculty of Engineering Universiti Putra Malaysia (Member) Wong Sai Voon, Ph.D. Associate Professor Faculty of Engineering Universiti Putra Malaysia (Member) ______________________ AINI IDERIS, Ph.D. Professor/Dean School of Graduate Studies Universiti Putra Malaysia Date: 10 MAY 2007

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DECLARATION

I hereby declare that the thesis is based on my original work except for quotations and citations which have been duly acknowledged. I also declare that it has not been previously or concurrently submitted for any other degree at UPM or other institutions.

______________________ HAMZAH BIN ADLAN

Date: 14 FEBRUARY 2007

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TABLE OF CONTENTS

Page DEDICATION I ABSTRACT II ABSTRAK III ACKNOWLEDGEMENTS VII APPROVAL VIII DECLARATION X LIST OF TABLES XI LIST OF FIGURES XIV LIST OF PLATES XVI LIST OF ABBREVIATIONS XVII

CHAPTER

1 INTRODUCTION 1 1.1 Background 1 1.2 Statement of Problem 7 1.3 Objectives of the Research 9 1.4 Scope of the Research 10

2 LITERATURE REVIEW 12 2.1 Natural gas 12

2.1.1 What is Natural Gas 12 2.1.2 What is CNG 14 2.1.3 Advantages of CNG 16

2.2 Direct Injection 21 2.2.1 Diesel Direct Injection 21 2.2.2 Petrol Direct Injection 24 2.2.3 Advantages of Direct Injection 26 2.2.4 Review on Current Application of CNG-DI vehicle in Automotive Sector 29

2.3 Transmission 30 2.3.1 Manual Transmission 35

2.3.1.1 3-speed sliding gear configuration 39 2.3.1.2 Synchronizing Mechanisms 44 2.3.1.3 Basic transmission formulation 46

XI

2.4 Review on Current Application of Transmission Matching Simulation Software 49

2.5 Summary of Literature Review 51

3 METHODOLOGY 53 3.1 Introduction 53 3.2 Structure of the Research 54 3.3 Simulation Construction Process 57

4 RESULTS AND DISCUSSION 61

4.1 Simulated Tool Interface 61 4.2 Simulated Ratio 66 4.3 Power and Torque of Petrol and Natural Gas fuelled engine 67 4.4 Hill Climbing Ability 74 4.5 Vehicle Result 76

4.5.1 Weight 76 4.6 Performance 78

4.6.1 Set 1 79 4.6.2 Set 2 82 4.6.3 Set 3 85 4.6.4 Gear Changing Speed 87 4.6.5 Overall Vehicle Performance 90

4.7 Comparison of Simulation and Actual Test Result 94

5 CONCLUSIONS AND RECOMMENDATIONS 96 5.1 Introduction 96 5.2 Conclusions 97 5.3 Recommendation for Future Work 100

REFERENCES 101 APPENDICES 104

BIODATA OF THE AUTHOR 112

XII

LIST OF TABLES

Table Page

2.1 Sample of natural gas composition 14

2.2 Opel Zafira Engine specifications 17

2.3 Emission comparison of vehicle using Natural Gas and petrol 18

2.4 Chemical properties of fuel 19

2.5 Performance comparison of petrol to diesel direct injection 28

4.1 Simulation transmission option 62

4.2 Simulated Ratios 66

4.3 CamPro engine specifications 70

4.4 Vehicle element weight 78

4.5 Comparison between simulations to actual test result 95

XIII

LIST OF FIGURES

Figure Page

2.1 Typical power and torque curve for small gasoline engine 32

2.2 Ideal engine power and torque 33

2.3 Simple diagram of manual transmission 38

2.4 Neutral Conditions 39

2.5 First Gear 40

2.6 Second Gear 41

2.7 High Gear 42

2.8 Reverse Gear 43

2.9 Synchronizer mechanism 45

3.1 Flowchart of the methodology 56

3.2 Flowchart of Simulation process 60

4.1 Simulation sample 63

4.2 Numerical result 64

4.3 Performance Curve 65

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4.4 Power and torque comparisons for petrol and methane using base CamPro using commercial software

under optimized condition 68

4.5 Prediction power and torque for CNG-DI engine 72

4.6 Power versus vehicle speed at different road gradient 75

4.7 Power versus vehicle speed for Set 1 80

4.8 Torque at wheel versus speed at every gear for Set 1 81

4.9 Power versus vehicle peed and for Set 2 83

4.10 Torque at wheel versus speed at every gear for Set 2 84

4.11 Power versus vehicle speed and for Set 3 85

4.12 Torque at wheel versus speed at every gear for Set 3 86

4.13 Gear changing speed for every set and their difference 88

4.14 Vehicle performance 91

4.15 Acceleration time attack 93

XV

LIST OF PLATES

Plate Page

2.1 Diesel system components: pump, injectors and Common rail 23

2.2 Direct Injection Injectors sample 24

2.3 Clutch friction plate 36

XVI

LIST OF ABBREVIATIONS

NGV Natural Gas Vehicle

DI Direct Injection

OPEC Organization of Petroleum Exporting

Countries

USA United State of America

UK United Kingdom

ASEAN Association of South East Asia Nation

PROTON Perusahan Otomobil National Berhad

BP British Petroleum

CNG Compressed Natural Gas

kW - kilowatt

rpm revolution per minute

Nm Newton meter

ECU Electronic Control Unit

EMS Engine Management System

NOx Nitrogen Oxides

LPG Liquid Petroleum Gas

BMW Bayerische Motoren Werke

VE Volumetric Efficiency

XVII

XVIII

GDI Gasoline Direct Injection

FD Final Drive

CVT Continuous Variable Transmission

AMT Automated Manual Transmission

MBT Maximum spark advance for Best Torque

USSR United Social Soviet of Russia

EUDC European emission Drive test Cycle

CoD Coefficient of Drag

N/V Engine revolution/ vehicle speed

BMEP Brake Mean Effective Pressure

NA Naturally Aspirated

DOHC Double OverHead Camshaft

NVH Noise, vibration and Harshness

CHAPTER 1

INTRODUCTION

1.1 Background

Lately, due to the escalating demand for gasoline and diesel, the price of

this precious commodity has skyrocketed to a new unprecedented level.

Hence, the Malaysian government has decided to encourage the

development and use of alternative fuels such as natural gas and bio-

diesel. The rise in crude oil prices has also shifted the efforts of countries

towards enhancing fuel economy. Natural Gas is abundant and cheaper

compared to other fuels. Vehicles that have been transformed from using

petrol or diesel to compressed natural gas show significant savings in fuel

economy and maintenance thanks to clean combustion although there is

some performance penalty. Matching the right transmission ratio is one of

the strategies that could enhance the performance of a Compressed

Natural Gas Direct Injection (hereafter CNG-DI) engine in a Natural Gas

Vehicle (hereafter NGV) to be at par with its gasoline counterpart.

Transmission or gearbox in general terms is undeniably one of the most

important engineering components in a modern day vehicle. It is the pair

of an engine and a perfect match to the engine is always an important

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criteria. The core principal of a transmission is to capture the torque

available at the rotating engine’s flywheel, transfer the torque via a

combination of gears, multiply the torque according to the selected gear

ratio, and finally transfers the modified torque via its body through the

transfer box or drive shaft and finally to the driven wheels, be it front, rear

or all wheel drive. In essence, the function of any transmission is to assist

the propulsion of a vehicle by varying torque distribution depending on

the vehicle linear speed and road gradient.

Product Planning executives and Powertrain engineers all around the

world consider many factors during the selection stage of a transmission

for their company’s model. This is because there are different types of

transmission that are priced differently. There is automatic, manual,

Automated Manual Transmission (AMT), Continuous Variable

Transmission (CVT), to name but a few. Besides budget and cost, the

most important criteria in selecting the suitable transmission are definitely

the requirement and demand of the intended sales market. For example,

80% of the European prefers manual transmission while 70% of Asian car

buyers would opt for automatic transmission. This is probably because in

Europe, the fuel cost is so high; the driver would sacrifice comfort by

driving the fuel frugal manual transmission. In the other hand, most of the

cities in Asian countries are very crowd; furthermore the traffic condition

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is not as good as the European that lead Asian people to opt for automatic

transmission car.

Whether it is an automatic gearbox or manual gearbox, the fundamental of

gear ratio calculation is relatively same. The main reason for this project

to concentrate on manual transmission is the simplicity of the structure.

Furthermore, they are easy to understand on how it works and relatively

carry lesser number of parts compare to any other type of transmission.

Manual transmission has better mechanical efficiency due to lesser

moving parts. In the other hands, automatic transmission unit has a torque

converter that has an impeller to rotate a fluid to convert rotating torque

from the engine into the drive shaft, then to the wheel. Thus, more rotating

parts and heat losses those lead to less mechanical efficiency. Manual

transmission is cheap to produce and easy to package into vehicle, thanks

to its smaller size compare to automatic transmission and relatively

effective cost solution when it comes into production that it will not reflect

high built-of-material overall cost. For example, 4-speed automatic

transmission is simply double the price of 5 speed manual transmission.

Even in Asia, manual transmission is less popular, but it is still a good

option for smaller car that has a small engine to compensate with low

engine output. It also has a low maintenance cost and most importantly, a

very robust unit that usually ended its life with the vehicle.

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There are numerous factors affecting transmission design. For a start,

packaging of an engine bay plays a vital role in deciding whether to use

four, five, six or even seven speed manual transmission. Most of high

performance car that usually has a longitudinal engine configuration

(engine is located parallel to the body line) has more gear ratios. High

performance car has a high performance engine that needs the power to be

divided evenly across the ratios. Engine bay for high performance car has

been designed to cater for big engine and transmission, thus allowing the

transmission to have more ratios. For example, Lamborghini Diablo has a

7-speed unit inside and similar to Ferrari F40 has 6-speed manual

transmission. On the other hands, small car that is targeted for decent

people usually has 5-speed manual transmission that located transversely

in the engine bay. Another factor that is affecting the design is the cost.

Since the cost is the most vital element in the modern automotive industry,

it is very clear to choose the right material and manufacturing process to

the given budget. Gear and shaft base material selection plus hardening

process (usually case hardening) has to be selected in order to produce

inner rotating parts. Transmission casing and ‘bell’ housing that usually

made by aluminum is always an option for normal car. But sometime the

lightweight magnesium casing is on option for a performance car. The

other factor is the torque capacity. The capacity depends on the amount of

torque produced by the engine, hence determines the heat treatment

process and base material selection. The rest of the deciding factors are

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minor but important on how rough or how smooth the gear change

depending on the surface finishing, dimensional tolerance and level/

direction of vibration coming from the engine.

For the new PROTON WAJA CNG-DI vehicle, there are five reasons why

the drive train engineers need to choose the proper transmission gear ratio

and the correct final drive. The first one is the different torque output and

characteristic from CNG-DI compare to gasoline engine. The second one

is the emission target, which differs by engine load and engine speed that

is not discussed in this project. Others are the vehicle weight, which is

very important in transmission tuning. Fourth reason is new target for

engine revolution to speed ratio (N/V ratio) that might be different based

on intended market or topography. Finally is the maximum torque

capacity for the internal gears could withstand that should be inline with

maximum torque produced by the engine..

The different gear ratios are necessary because the engine develops

relatively little power at low engine speeds. The engine must be turning at

a fairly high speed before it can deliver enough torque to start the vehicle

moving. Transmission torque capacity would also determine the type of

heat treatment for the base material of the moving parts. Design tolerances

and surface finish would affect the smoothness of gear changing, vibration

and road shock dampening. The strategies employed in the transmission

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design are various. Among the transmission design considerations are

environmental such as the End of Life Vehicle (ELV) regulation

compliance, which is to include recyclable parts. Other considerations

include collision safety and the use of lightweight materials. The

transmission can also be designed to meet the collision safety standard.

The engineers can also juggle the option of a lightweight transmission to

improve the fuel economy of the vehicle. Finally, the engineers can

strategize to reduce the size of the transmission so that it is compact and

can be packaged in many vehicles and thus increase the possibility of

cross company sales.

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