i

PULSE DETONATION ENGINE PERFORMANCE AND THRUST

IMPROVEMENT USING EJECTOR

HISHAMMUDIN AFIFI BIN HUSPI

A dissertation submitted in partially fulfilment of the

requirements for the award of the degree of

Master of Engineering (Mechanical)

Faculty of Mechanical Engineering

Universiti Teknologi Malaysia

FEBRUARY 2012

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To my beloved mother, father, wife and daughter

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ACKNOWLEDGEMENT

Assalamualaikum...

Millions of thanks to ALLAH S.W.T who has given me the strength to overcome all

difficulties especially in completing this thesis. Selawat and salam to Prophet

Muhammad SAW who has been endowed Al-Quran and Sunnah as our guidance.

Firstly, I would like to thank my supervisor, Assoc Prof Dr Mazlan Abdul Wahid

and Ahmad Faiz for all the help and guidance in finishing this project.

Special thanks to my parents, wife and daughter for always supporting me and

encouraging me to complete this heavy task.

Not forgotten, thanks also to JPA KPT and UNIMAS for sponsoring my study, my

friends for understanding me, and Universiti Teknologi Malaysia for providing me

all necessary facilities.

Thank You

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ABSTRAK

Tesis ini adalah berkenaan peningkatan tujahan yang dihasilkan oleh pulse

detonation engine (PDE) dengan menggunakan pelenting pada hujung tiub. Terdapat

dua kaedah untuk meningkatkan tujahan PDE, yang pertama adalah dengan

menggunakan komponen-komponen enjin yang berprestasi tinggi, dan yang kedua

dengan memperbaiki mekanisma dalam menghasilkan detonasi. Tetapi, langkah ini

memerlukan pendekatan yang lebih maju dan kompleks. Terdapat kaedah yang lebih

ringkas dan mudah untuk meningkatkan tujahan yang dihasilkan PDE iaitu dengan

menggunakan pelenting pada hujung terbuka PDE. Oleh itu, objektif tesis ini adalah

untuk meningkatkan prestasi PDE supaya detoansi yang terhasil pada kadar yang

stabil dan memuaskan. Dalam kajian ini kesan peningkatan daya tujahan hasil

daripada penggunaan pelenting juga diukur. Kajian ini telah dijalankan di High

Speed Reacting Flow Laboratory (HiREF), Fakulti Kejuruteraan Mekanikal,

Universiti Teknologi Malaysia. PDE telah beroperasi menggunakan gas propana,

C3H8 sebagai bahan bakar dan oksigen, O2 sebagai pengoksida pada kadar 5Hz.

Empat jenis pelenting yang telah diuji dalam projek ini adalah jenis lurus, menumpu,

mencapah dan kombinasi menumpu dan mencapah. Kesemua pelenting tersebut

mempunyai panjang 400 mm dan diameter bibir pelenting 130 mm. Peningkatan

tujahan maksimum telah diukur dengan menggunakan sel beban. Peningkatan paling

tinggi iaitu sebanyak 12.6% telah diperolehi dengan penggunaan pelenting menumpu

yang dipasang pada kedudukan hiliran. Eksperimen ini juga menunjukkan pelenting

sangat sensitif dengan kedudukan paksi kepada hujung PDE.

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ABSTRACT

This thesis is concerning the improvement of thrust by employing ejector at

the end tube of pulse detonation engine (PDE). There are two ways of improving the

thrust of PDE, one is to choose higher performance engine component and the other

is in to improve the mechanism of detonation initiation. But sometimes those steps

required more advanced and sometimes more complex mechanism. This thesis

suggest a simpler and easier way to improve thrust in PDE by employing ejector of

different geometries at the open end of detonation tube. Therefore the objective of

this thesis is to improve the performance of the PDE so that stable detonation can be

achieved at a reasonable repetitive rate. In this study the improvement on thrust

generated by the installation of ejector is quantified. The study is conducted in High

Speed Reacting Flow Laboratory (HiREF), Faculty of Mechanical Engineering,

Universiti Teknologi Malaysia. The PDE is operated with propane as fuel and

oxygen as the oxidiser at the frequency of 5Hz. The four ejectors tested in this study

namely straight, convergent, divergent and convergent-divergent ejectors. All

ejectors have similar length and inlet diameter which are 400 mm and 130 mm

respectively. The maximum augmentations for each ejector were measured using

load cell. The highest improvement on thrust generated which is 12.6% higher than

the baseline configuration has been achieved with the use of convergent ejector that

is installed at downstream position. The study shows that the ejectors are very

sensitive with its axial position to the open end of PDE.

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TABLE OF CONTENTS

CHAPTER TITLE PAGE

DECLARATION ii

DEDICATION iii

ACKNOWLEDGEMENT iv

ABSTRAK v

ABSTRACT vi

TABLE OF CONTENTS vii

LIST OF TABLES x

LIST OF FIGURES xi

LIST OF APPENDICES xiii

CHAPTER 1 INTRODUCTION 1

1.1 Research Background 3

1.2 Objective 4

1.3 Scopes 4

1.4 Problem Statement 5

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CHAPTER 2 LITERATURE REVIEW 7

2.1 Detonation 7

2.2 Pulse Detonation Engine 10

2.3 Augmentor 11

2.4 Previous Study on Thrust Optimization

for PDE

13

2.4.1 Thrust Optimization Using Nozzles 13

2.4.2 Thrust Optimization Using Ejectors 15

2.5 Thrust Augmentation 18

CHAPTER 3 METHODOLOGY 19

3.1 Ejector Configuration 20

3.1.1 Ejector Inlet 20

3.1.2 Ejector Exhaust Geometry 21

3.2 Experimental Setup 25

3.3 Thrust Measurement 27

CHAPTER 4 RESULTS AND DISCUSSIONS 31

4.1 PDE Performance 32

4.1.1 Improvement in Data Colection 35

4.2 PDE Without Ejector 37

4.3 Effect of Straight Ejector 40

4.4 Effect of Convergent Ejector 42

4.5 Effect of Divergent Ejector 43

4.6 Effect of Converge-Divergent Ejector 45

4.7 Effect of Ejector Geometry 46

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CHAPTER 5 CONCLUSION 48

REFERENCES 50

APPENDICES 53

x

LIST OF TABLES

TABLE NO. TITLE PAGE

3.1 Basic configurations for the ejector 21

xi

LIST OF FIGURES

FIGURE NO. TITLE PAGE

2.1 The Rankine-Hugoniot curve for combustion process 8

2.2 The pulse detonation engine cycle. 10

2.3 Ejector schematic 11

2.4 (i) Pulse Detonation Engine tube with various exit

nozzles, (ii) the shapes of the four different exit

nozzles and (iii) the 2D mesh used for the CD Nozzle

case

14

2.5 Shadowgraph images of PDE –Ejector interaction.

Axial position, x/DPDE=2.

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3.1 Inlet geometry of ejector 21

3.2 Left; ejector right; ejector inlet 22

3.3 Sketches of ejector used in experiment. From above;

Convergent ejector, middle; Divergent ejector,

bottom; Converge-Divergent ejector

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3.4 From left; Diverge ejector, Converge ejector,

Converge-Diverge ejector and Straight ejector

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3.5 PDE sequences 25

3.6 Diagram of ejector geometry 26

3.7 Position of the ejector 27

3.8 Schematic diagram of the experimental setup 28

3.9 Idealized pressure history at thrust surface 29

3.10 (a) Pressure transducer; (b) 9331B load cell 30

4.1 Thrust recorded by previous researcher 32

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4.2 MSD digital 6A ignition control 33

4.3 The improvements of the thrust generated by the

PDE

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4.4 Block diagrams constructed using DAQ Assistant for

recording the data

35

4.5 Improved NI-DAQmx block diagrams for recording

the data

36

4.6 Thrust produced by the PDE operated at frequency 5

Hz

37

4.7 Pressure profile of transducer 1 with frequency of 5

Hz

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4.8 Baseline experiment. (a) Pressure profile recorded by

pressure transducer 1. (b) Pressure profile recorded

by pressure transducer 2

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4.9 Thrust produced by the PDE operated at frequency

5Hz with straight ejector at position x/DPDE=-1

(Upstream)

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4.10 The effect of axial position on ejector performance

for straight ejector

41

4.11 The effect of axial position on ejector performance

for convergent ejector

43

4.12 The effect of axial position on ejector performance

for divergent ejector

44

4.13 The effect of axial position on ejector performance

for converge-divergent ejector

45

4.14 The effect of different type of ejector geometry 46

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LIST OF APPENDICES

APPENDIX TITLE PAGE

A B NI-DAQ block diagram for simulating the signals 53

B The propane, C3H8-oxigen mixtures characteristics

calculated by CEA code

54

C Lab Sheet and Check List

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CHAPTER 1

INTRODUCTION

Pulse detonation engines (PDEs) have shown great potential in converting

the chemical energy content of combustible mixtures by using detonation process.

Detonation is a reactive combustion wave that propagated supersonically. PDE has a

simpler and lighter design in comparison to the current conventional propulsion

system namely gas turbine.

For a PDE to operate, initially it requires the combustible mixture to be filled

completely in the combustion tube. Then the combustible mixtures need to be ignited

by using a sufficient energy initiating device. Detonation wave created will generate

a sudden high pressure rise. These will be accompanied by strong shock wave that

propagates through the tube open end.

A lot of studies in PDE have been conducted by various researchers so that it

can be used as the main propulsion system for aircraft. It is believed that PDE

produced more thrust than other propulsion system. There are two ways of

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improving the thrust of PDE, one is to improve the engine component and the other

is in improving the mechanism of the PDE. But sometimes those step required more

advance or more complex mechanism. There is simpler and easier way to improve

thrust in PDE that is to employ ejector at the outlet of PDE. There are several types

of augmentor. Currently nozzles and ejectors are the most common types that are

widely studied [15].

Nozzle is a mechanical device attached at the end of the detonation tube. It is

used to utilize the combustion energy to augment the thrust generated by the Pulse

Detonation Engine. Ejector is a separated device which is placed at the open end of

Pulse Detonation Engine to increase the amount of thrust produced. Theoretically, an

ejector is a coaxial duct placed at the opened end of Pulse Detonation Engine that

performs as a fluidic pump. The surrounding ambient air enters the ejector due to the

primary exhaust flow from the Pulse Detonation Engine and causes the increase in

the momentum of engine exhaust flow which lead to the increase of thrust generated

[1].

In this thesis, the effects of ejectors to the performance of Pulse Detonation

Engine will be investigated. The parameters that determine the thrust augmentation

of including its inner geometry as well as its position relative to the PDE tube end. In

the end of this thesis, the best ejector geometry which produces the optimum thrust

augmentation will be proposed.

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1.1 Research Background

As mentioned before, Pulse Detonation Engine (PDE) has a big potential to

be applied as the main aircraft propulsion system. Base on theoretical calculation,

this type of engine will generate more impulsive thrust than other types of

conventional engines [6]. In order for this PDE concept to become reality, a

significant amount of researches are required

Various researchers have reported on the use of nozzle as augmentor [3, 4, 5,

7 and 8]. Ejectors also have been used to increase the thrust generated from PDE.

Even though there were numbers of researches working on this field, there was no

work done to investigate the effect of ejector installation on the PDE using propane

as a fuel.

Optimization of thrust generation is important in utilizing the energy released

by the Pulse Detonation Engine. Therefore, this research will investigate the

optimization of the thrust generated from Pulse Detonation Engine using ejectors of

several geometries. The PDE in this work was fuelled with propane, C3H8 and

oxygen as the oxidizer. The PDE in this research was operated at a frequency of

5Hz.

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1.2 Objective

There are three objectives listed in this project. The first objective is to

improve the operation of Pulse Detonation Engine (PDE). The other is to investigate

the effect of ejector on the thrust generated by gaseous fuel PDE. The last objective

is to determine the maximum improvement of thrust generated by the installation of

ejector on PDE.

1.3 Scopes

There are several scopes listed to be completed in the end of this project. The

research is focused mainly on the experimental. Several ejector geometries are

fabricated. The ejectors are attached to the end of the Pulse Detonation Engine and

the performance is evaluated by measuring the thrust generated using load cell that

connected to data acquisition system. Pressure transducer also connected to the PDE

to record the pressure profile trend generated by the PDE.

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1.4 Problem Statement

PDE are currently being investigated as a potential candidate for the

technological development of a new and more efficient aerospace propulsion system.

In order to optimize the thrust generated from PDE, several steps of further

refinement are required. There are two ways of improving the thrust of PDE, one is

to improve the engine component and the other is in improving the mechanism of the

PDE. But sometimes those steps required more advanced and sometimes more

complex mechanism. There is a simpler and easier way to improve thrust in PDE

that is to employ ejector at the outlet of PDE. Therefore the objective of this thesis is

to see the effect of ejector on the thrust produced by PDE. The study was conducted

in High Speed Reacting Flow Laboratory (HiREF), Faculty of Mechanical

Engineering, Universiti Teknologi Malaysia. After a lot of research programs in

studying and developing the pulse detonation engine (PDE), there is a need to make

a research in optimizing the thrust generated from Pulse Detonation Engine. Previous

research works confirmed that Pulse Detonation Engine with ejectors is extremely

effective in increasing the thrust. It is due to more efficient energy-transfer process

between the primary and secondary flows that result from the dominant effects of the

starting vortex ring [1].

Many factors need to be considered in optimizing the thrust. A numbers of

parameters which affect the performance of Pulse Detonation Engine need to be

identified. Until today, there are no solid theories regarding to the unsteady ejectors.

On the other hand, steady ejectors’ theories were well-established [10, 13, 20].

Due to this, a research on optimizing the thrust using ejector should be

attempted. In this research, the effect of ejector will be investigated by using the

pulse detonation engine fuelled with propane C3H8 and used oxygen as the oxidizer.

There is no work done in this field using this type of fuel. Also, the experiments will

be held using low frequency Pulse Detonation Engine of 5 Hz. Previous works were

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done using higher frequency rates of Pulse Detonation Engine ranges from 10 Hz to

20 Hz. In the end of this research, the best modification in optimizing the thrust

generated will be proposed.

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REFERENCES

1 N. Caldwell, E. Gutmark, “Investigation of Fundamental Processes Leading

to Pulse Detonation Engine/Ejector Thrust Augmentation”, 46th

AIAA

Aerospace Sciences Meeting and Exhibit.

2 N. Caldwell and E. Gutmark, “A Review of Pulse Detonation Engine

Research at the University of Cincinnati”, 43rd

AIAA/ASME/SAE/ASEE

Joint Propulsion Conference & Exhibit, 8-11 July 2007, Cincinnati, OH,

AIAA 2007-5697.

3 V. E. Tangirala and A. J. Dean, “Performance Estimations of a Pulse

Detonation Engine with Exit Nozzle”, 42nd

AIAA/ASME/SAE/ASEE Joint

Propulsion Conference & Exhibit, 9-12 July 2006, Sacramento, CA, AIAA

2006-4792.

4 V. E. Tangirala and A. J. Dean, “Performance of a Pulse Detonation Engine

Under Subsonic and Supersonic Flight Conditions”, 45th

AIAA Aerospace

Sciences Meeting and Exhibit 8-11 January 2007, Reno, NV, AIAA 2007-

1245

5 K. Kailasanath, “Research on Pulse Detonation Combustion Systems – A

Status Report”, 47th AIAA Aerospace Sciences Meeting Including The New

Horizons Forum and Aerospace Exposition, 5 - 8 January 2009, Orlando,

Florida, AIAA 2009-631

6 J. Kasahara, T. Arai and A. Matsuo, “Experimental Analysis of Pulse

detonation engine Performance by Pressure and Momentum Measurements”

41st aerospace Sciences Meeting and Exhibit, January 6 – 9, 2003, Reno,

Nevada, AIAA 2003-893.

51

7 Y. Kimura, A. K. Hayashi and E. Yamada, “Performance Evaluations of

Exhaust Nozzles for Pulse Detonation Engines”, 46th AIAA Aerospace

Sciences Meeting and Exhibit 7 - 10 January 2008, Reno, Nevada, AIAA

2008-984.

8 M. Cooper, S. Jackson, J. Austin, E. Wintenberger, J.E. Shepherd, “Direct

Experimental Impulse Measurements for Detonations and Deflagrations,”

Graduate Aeronautical Laboratories, California Institute of Technology,

Pasadena, CA 91125, AIAA 01 3812.

9 A. Glaser, “Effects of Tube and Ejector Geometry on the Performance of

Pulse Detonation Engine Driven Ejectors”, 42nd

AIAA/ASME/SAE/ASEE

Joint Propulsion Conference & Exhibit, 9-12 July 2006, Sacramento,

California.

10 A.Rasheed, “Experimental and Numerical Investigations of Ejectors for PDE

Applications”, 39th

AIAA/ASME/SAE/ASEE Joint Propulsion Conference

and Exhibit, 20-23 July 2003, Huntsville, Alabama.

11 S. Yungster, “Analysis of Nozzle Effects on Pulse Detonation Engine

Performance”, 41st Aerospace Sciences Meeting and Exhibit, 6-9 January

2003, Reno, Nevada, AIAA 2003-1316

12 K. Kailasanath, “A Review of Research on Pulse Detonation Engine

Nozzles”, 37th

AIAA/ASME/SAE/ASEE Joint Propulsion Conference &

Exhibit, 8-11 July 2001, Salt Lake, Utah, A01-34554.

13 D. Allgood and E. Gutmark, “Performance Measurements of Pulse

Detonation Engine Ejectors”, 43rd

AIAA Aerospace Sciences Meeting and

Exhibit, 10-13 January 2005, Reno, Nevada, AIAA 2005-223.

14 A.Glaser, “Performance and Environmental Impact Assessment of Pulse

Detonation Based Engine Systems”, PhD Thesis, 2007

52

15 D. Allgood, “An Experimental and Computational Study of Pulse Detonation

Engines”, PhD Thesis, 2004.

16 W. Presz, Jr. “Thrust Augmentation with Mixer/Ejector Systems”, 40th

AIAA

Aerospace Sciences Meeting & Exhibit, 14-17 January 2002, Reno.

17 E. Wintenberger, J.M Austin, M.Cooper, S. Jackson, and J.E. Shepherd, “An

Analytical Model for the Impulse of a Single-Cycle Pulse Detonation

Engine,” 37th

AIAA/ASME/SAE/ASEE Joint Propulsion Conference, July 8

– 11, 2001 salt Lake City, UT, AIAA 2001 – 3811.

18 J. Wilson, “The Effect of Pulse Length and ejector Radius on Unsteady

Ejector Performance”, 41st AIAA/ASME/SAE/ASEE Joint Propulsion

Conference & Exhibit, 10-13 July 2005, Tucson, Arizona. AIAA 2005-3829.

19 P. Changxin, Z. Qun, Y. Cheng, C. Wenjuan, F. Wei, Y. Chuanjun,

“Experimental Study of an Air-breathing Pulse Detonation Engine Ejector”,

Experimental Thermal and Fluid Science Jurnal, 2011

20 K. Landry, R. Shahadeh, “Effect of Operating Frequency on PDE driven

Ejector Thrust Performance”, 41st AIAA/ASME/SAE/ASEE Joint

Propulsion Conference & Exhibit, 10-13 July 2005, Tucson, Arizona. AIAA

2005-3832.

21 A.Glaser, N. Caldwell, E. Gutmark, “Experimental Study of Ejector Driven

by a Pulse Detonation Engine”, 45th

AIAA Aerospace Sciences Meeting and

Exhibit, 8-11 January 2005, Reno, Nevada. AIAA 2007-447.

22 M. Z. Ahmad Faiz, “Development of Pulse Detonation Engine”, Master

Thesis, UTM 2011

23 Kistler Instrument http://www.kistler.com/