Amardeep report

DESIGN AND STUDY OF SWIRL INJECTOR OF PULSE DETONATION ENGINE
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Gurukul Vidyapeeth Institute of Engg & Tech
INDUSTRIAL TRAINING REPORT
(JULY 2015 – DEC 2015)
DESIGN AND STUDY OF SWIRL INJECTOR OF PULSE
DETONATION ENGINE
AT
TERMINAL BALLISTICS RESEARCH LABORATORY (T.B.R.L.),
Submitted by
AMARDEEP SINGH
1252577
Under the Guidance of
MR. MUNESH KUMAR PATLE
SCIENTIST ‘D’
PULSE DETONATION SYSTEM GROUP
In partial fulfillment for the award of the degree of
BACHELOR OF TECHNOLOGY
IN
AERONAUTICAL ENGINEERING

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Certificate

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DECLARATION
I hereby declare that this TRAINING REPORT “DESIGN & STUDY OF SWIRL INJECTOR
OF PULSE DETONATION ENGINE “ by AMARDEEP SINGH (1252577), being submitted
in partial fulfillment of the requirements for the degree of Bachelor of Technology in
AERONAUTICAL ENGINEERING BRANCH under Faculty of GURUKUL VIDYAPEETH
INSTITUTE OF ENGINEERING AND TECHNOLOGY, during the academic year 2015-16, is
a bonafide record of my work carried out in the TERMINAL BALLISTICS RESEARCH
LABORATORY,CHANDIGARH under guidance and supervision of MR.MUNESHKUMAR
PATLE, Sc.’D’ (Pulse Detonation Systems) and has not been presented elsewhere.
Date………… AMARDEEP SINGH
(1252577)
Certified that the above statement made by the student is correct to the best of our knowledge and
belief.
TRAINING HEAD
Mr. Munesh Kumar Patle
Scientist ‘D’
DIVISION HEAD JOINT DIRECTOR
Mr. Manmohan Sandhu Mr. Subhash Chander
Scientist ‘E’ Scientist ‘F’
PDS Group Zone – I

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ABSTRACT
Pulse Detonation is a propulsion technology that involves detonation of fuel to
produce thrust more efficiently than current engine systems. By literature survey and library
research, it is shown that Pulse Detonation Engine (PDE) technology is more efficient than current
engine types by virtue of its mechanical simplicity and thermodynamic efficiency. As the PDE
produces higher specific thrust than comparable ramjet, scramjet engines at speeds of up to
approximately Mach 2.3 to 5, it is suitable to use as part of a multistage propulsion system. The
PDE can provide static thrust for a ramjet or scramjet engine, or operate in combination with
turbofan systems. As such it sees potential applications in many sectors of the Aerospace,
Aeronautics and Military industries. However, there remain engineering challenges that must be
overcome before the PDE can see practical use. Current methods for initiating the detonation
process need refinement. To this end, many government and private organizations around the
world are working on PDS research and further development.
In India, DRDO’s TERMINAL BALLISTICS RESEARCH LABORATORY (TBRL) is
also working on such an advanced and challenging technology of Pulse Detonation Engine. I have
undergone my 6 months industrial training on this advanced field in the areas of introductor y
study/knowledge of PDE Theory and Design & Development of Swirl injector of a PDE.

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CONTENT
1.ORGANISATIONDETAILS
1.1 MISISTRY OF DEFRNCE……….
1.2 DEFENCE RESEACH & DEVELOPMENT ORGANISATION (DRDO)………………...
1.3 LABORATORIES AND ESTABLISHMENTS…………………
1.4 TERMINAL BALLISTICS RESEARCH LABORATORY (TBRL)………………..
1.4.1 VISION, MISSION AND CHARTER OF DUTY
1.4.2 AREAS OF WORK
1.4.3 ACHIEVEMENTS
2. INTRODUCTIONTO PULSE DETONATION
2.1 INTRODUCTION………………………
2.2 DETONATION V/S DEFLAGRATION…………….
2.3 MAIN COMPONENTS OF PDE…………….
2.4 WORKING CYCLES ………….
2.5 STAGES OF PDE…………….
2.6 COMPARISON OF VARIOUS PROPULSION SYSTEM…………….
3. FUEL INJECTION
3.1 REQUIREMENT OF INJECTORS………………………
3.2 SWIRL INJECTOR……………………………
3.2.1 INTRODUCTION
3.2.2 SWIRLER
3.2.3 INTERNAL FLOW OF SWIRLER
3.2.4 ADVANTAGES OF SWIRL INJECTOR
3.2.5 PULSATING FLOW OF SWIRL INJECTOR

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4. SPRAY FORMATION
4.1 INTRODUCTION………………………………..
4.1 EFFECT OF SWIRLER IN SPRAY FORMATION………………………….
5. DROPLET SIZE DISTRIBUTION
6.CALCULATION AND DESIGN PART
7.HELIX ANGLE FOR SWIRLER
8.OBSERVATIONS
9.SOLID MODELS
10. EXPERIMENTALSET –UP
10.1 SET UP…………………………………………….
10.2 OBJECTIVES OF SET UP………………………………
10.3 PROCEDURE FOR MMD …………………………………
10.4 MIXING…………………………………..
11.CONCLUSION
12.REFERENCES
13.APPENDIX

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Defence Research & Development Organization
(D.R.D.O.)
Drdo Logo
Ministry of Defence
Before India became an independent nation in 1947, the defence of the country was the
responsibility of the Defence Department (under the British rule). Soon after India became
independent, the Defence Department became the Ministry of Defence, headed by a Minister of
the Cabinet Rank. According to the Constitution of India, the President of India is the supreme
commander of the Armed Forces and executive responsibility for national defence rests with the
Union Cabinet of which Defence Minister is an important member. The official designation of the
Defence Minister is Raksha Mantri (RM) who is assisted by a Ministry of State called Rajya
Raksha Mantry (RRM) assisting the RM.
Defence Research& DevelopmentOrganisation
Defence Research & Development Organization (DRDO) works under Department of
Defence Research and Development of Ministry of Defence. DRDO is dedicatedly working
towards enhancing self-reliance in Defence Systems and undertakes design & development
leading to production of world class weapon systems and equipment in accordance with the
expressed needs and the qualitative requirements.DRDO while striving to meet the Cutting edge
weapons technology requirements provides ample spinoff benefits to the society at large thereby
contributing to the nation building.DRDO makes India prosperous by establishing world-class
science and technology base andprovide our Defence Services decisive edge by equipping them
with internationally competitivesystems and solutions.

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The Defence Research and Development Organisation (DRDO) is an agency of
the Republic of India, responsible for the development of technology for use by the military,
headquartered in New Delhi, India. It was formed in 1958 by the merger of the Technical
Development Establishment and the Directorate of Technical Development and Production with
the Defence Science Organisation. It is under the administrative control of the Ministry of
Defence, Government of India. Prof. DS Kothari, the eminent scientist and educationist was the
first to head the Organization which has been led over the years by illuminati of the caliber of Dr
APJ Abdul Kalam. Sir S Christopher is the current head of the DRDO.
DRDO Bhawan, Headquarters at New Delhi
The 52 DRDO labs, based on their core-competence, are classified into nine clusters, namely,
Aeronautics, Armaments, Combat Vehicles and Engineering, Electronics and Computer Sciences,
Materials, Missiles and Strategic Systems, Micro Electronics and Devices, Naval Research and
Development, and Life Sciences. Devoted to innovation and excellence, DRDO remains
committed to make India strong and self-reliant. It has designed, developed and product ionized
world-class weapon systems, equipment, and complex technologies, which include strategic and
tactical missiles, combat aircrafts and aeronautical systems, unmanned aerial vehicles, combat
vehicles, armaments and ammunition, radars, electro-optic and acoustic sensors, electronic
warfare systems, life-support systems and materials. The production value ofMajor DRDO
systems inducted into the Services during the last decade stands at over Rs 1, 20,000 crores.
Presently, the Organization is backed by over 5000 scientists and about 25,000 other scientific,
supporting personnel.

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Laboratories
Aeronautics
Aeronautical Development Establishment (ADE), Bangalore
Aerial Delivery Research & Development Establishment (ADRDE), Agra
Centre for Air Borne Systems (CABS), Bangalore
Defense Avionics Research Establishment (DARE), Bangalore
Gas Turbine Research Establishment (GTRE), Bangalore
Center for Military Airworthiness & Certification (CEMILAC), Bangalore.
Aeronautics
Armaments
Armament Research & Development Establishment (ARDE), Pune
Centre for Fire, Explosive & Environment Safety (CFEES), Delhi
High Energy Materials Research Laboratory (HEMRL), Pune
Proof & Experimental Establishment (PXE), Balasore
Combat Vehicles and Engineering
Combat Vehicles Research & Development Est. (CVRDE), Chennai
 Vehicle Research & Development Establishment (VRDE), Ahmednagar
 Research & Development Establishment (R&DE), Pune
 Snow & Avalanche Study Estt (SASE), Chandigarh

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Combat Vehicles Armaments
Electronics & Computer Sciences
 Advanced Numerical Research & Analysis Group (ANURAG), Hyderabad
 Center for Artificial Intelligence & Robotics (CAIR), Bangalore
 DRONA CELL, Delhi
 Defence Electronics Application Laboratory (DEAL), Dehradun
 Defence Electronics Research Laboratory (DLRL), Hyderabad
 Defence Terrain Research Laboratory (DTRL), Delhi
 Defence Scientific Information & Documentation Centre (DESIDOC), Delhi
 Instruments Research & Development Establishment (IRDE), Dehradun
 Laser Science & Technology Centre (LASTEC), Delhi
 Electronics & Radar Development Establishment (LRDE), Bangalore
 Microwave Tube Research & Development Center (MTRDC), Bangalore
 Scientific Analysis Group (SAG), Delhi
 Solid State Physics Laboratory (SSPL), Delhi

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Life Sciences
 Defence Agricultural Research Laboratory (DARL), Pithoragarh
 Defence Bio-Engineering & Electro Medical Laboratory (DEBEL), Bangalore.
 Defence Food Research Laboratory (DFRL), Mysore.
 Defence Institute of Physiology & Allied Sciences (DIPAS), Delhi
 Defence Institute of Psychological Research (DIPR), Delhi
 Institute of Nuclear Medicine & Allied Sciences (INMAS), Delhi
 Defence Research & Development Establishment (DRDE), Gwalior
Materials
 Defence Laboratory (DLJ), Jodhpur
 Defence Metallurgical Research Laboratory (DMRL), Hyderabad
 Defence Materials & Stores Research & Development Establishment (DMSRDE),
Kanpur
Missiles
 Defence Research & Development Laboratory (DRDL), Hyderabad
 Institute of Systems Studies & Analyses (ISSA), Delhi
 Integrated Test Range (ITR), Balasore
 Research Center Imaret (RCI), Hyderabad
 Terminal Ballistics Research Laboratory (TBRL), Chandigarh

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NavalResearch& Development
 Naval Materials Research Laboratory (NMRL), Ambernath
 Naval Physical & Oceanographic Laboratory
(NPOL), Cochin
 Naval Science & Technological Laboratory (NSTL), Vishakhapatnam
Navy Research & Development
Missiles

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Terminal Ballistics ResearchLaboratory
Terminal Ballistics Research Laboratory (TBRL) was envisaged in 1961 as one of the
modern armament research laboratories under the Department of Defence Research &
Development. The laboratory became fully operational in 1967 and was formally inaugurated in
January 1968 by the then Defence Minister. While the main laboratory is situated in Chandigarh,
the firing range, spread over an area of 5500 acre, is located at Ramgarh in Haryana, 22 km away
from Chandigarh. Over the past three decades, the Laboratory has grown into an institution of
excellence and has become one of the major technical bases in the field of armament studies in
DRDO.
The laboratory has it’s headquarter at Sector 30, Chandigarh and technical area known as
TBRL Ranges, spread over 5500 acres at Village Ramgarh, Distt. Panchkula, Haryana. TBRL
Ranges are divided into a number of technical zones / trial areas which have been so designed and
spaced to allow conduct of experimental trials independent of each other. Each technical zone has
been equipped with highly specialized instruments and diagnostic facilities, which generate
critical inputs for the design and development of warheads and other armament system. The main
features of the trial areas are that the instruments are kept in strong RCC bunkers and explosive
or ammunition are detonated in the open. This gives flexibility in operation and permits explosion
of high calibre warheads, ammunition and large explosive charges with adequate safety measures.
The laboratory is certified as per International Quality Management Systems Standard ISO
9001:2008 by Standardization Testing and Quality Certification Services (STQC), Department of
Information Technology (DIT), Government of India.

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Vision, Missionand Charter of Duty
 Vision
Terminal Ballistics Research Laboratory envisaged self-reliance in the development of the
technologies related to conventional and nonconventional Warhead systems and provide
state-of-art diagnostics facilities for assessment of terminal effects of armament system.
 Mission
Terminal Ballistics Research Laboratory will strive for self-sufficiency and self-reliance
in critical areas for development of technologies related to conventional and non-conventional
weapons and provides facilities for transient phenomenon studies for development of new
armament stores.
 Charter of Duty
To conduct basic and applied research work in detonics, energetic materials, blast and
damage, defeat of armour, immunity and lethality, design, development and performance
evaluation of armament stores.
Areas of Work
TBRL conducts basic and applied research in the fields of high explosives, detonics
and shock waves. It is also involved in evolving data and design parameters for new armaments,
as well as assessing the terminal effects of ammunition.
Other areas of work include:
 Performance of armour defeating projectiles and immunity profiles.
 Studies of ground shock, blast damage, fragmentation and lethality.
 Preparation of safety templates for various weapons.
 Studies of underwater detonics and pressure wave propagation

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 Explosive forming, cladding and welding.
 Detonics of high explosives.
 Applied research in detonics
 Technology for design and development of Shaped Charges and Explosively Formed
Penetrators for anti-tank, anti-ship and anti-submarine applications
 Technology for generation of high energy electrical pulse power through explosive driven
magnetic flux compression
 Blast, Lethality and Fragmentation studies of warheads, shells and other ammunitions.
 Captive flight testing of Bombs, Missiles and Airborne systems.
 Ballistics evaluation of various protective system like body armour, vehicle armour and
helmets against small arm ammunition.
 Design and development of Baffle Ranges, Warhead and Exploder for Torpedoes, Bund
Blasting Devices, Multi-mode Hand Grenade, Non-lethal plastic and frangible bullets,
High voltage- high energy electrical power packs.
Achievements
 Establishment of Ultra High Speed photography and Flash Radio photography
(300 KV) techniques in 1968.
 Bund blasting device inducted into service with 1440 Nos. of Limited Service Production
order -2002.
 ISO 9001: 2000 / certification granted by STQC, New Delhi in Jan 2005
 Baffle Rang-Smart Solution for small arms practice firing.
 TBRL has designed and developed Bund Blasting Device, based on the principle of hollow
charge and a rocket assisted high explosive filled follow through projectile.
 Multi-mode Hand Grenade.
 Warhead and Exploder of torpedo advanced and light (TAL).
 Non-lethal ammunition-Plastic bullets, frangible ceramic and metal ammunition.
 Explosive driven high energy pulse power technology.
 Shaped Charges & Explosive Formed Projectile (EFP).
 Developed Indigenous plastic bonded explosives, digital blast data recorder, indigenous
transducer for blast measurement, Impulse generator.
 Pulse Detonation System (PDS).
 Rail Track Rocket Sled (RTRS) National Test Facility.

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PULSE DETONATION ENGINE
Introduction of Pulse DetonationEngine
In all air breathing and rocket engines, oxidizer and fuel
combustion takes place at lower speed i.e. velocity of 20-30 m/sec. It is called subsonic
combustion or deflagration combustion. The pulse detonation engine is another innovative
concept of air breathing engine, which is currently in active development that operates on
detonation combustion principle.
Pulse detonation engines (PDEs) have received
considerable attention over the past decade. These engine use detonation waves that propagates
through a premixed fuel/air mixture and produce large chamber pressure and thereby thrust.
Because the combustion takes place so rapidly, the charge (fuel/air mix) does not have time to
expand during this process, so it takes place under almost constant volume. Constant volume
combustion is more efficient than open-cycle designs like gas turbines, which leads to greater fuel
efficiency. PDEs are predicted to be very efficient and offer good thrust characteristics from the
low subsonic to the high supersonic flight regimes, but the engine operates in a pulsed mode, so
the thrust is varying in time and the detonation must be initiated each time. The system is
complicated because fast purging and refilling are required.
Schematic of a basic pulse detonation engine with valves at the inlet and a nozzle at the
exhaust

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Detonationv/s Deflagration
Detonation is a supersonic combustion process which is essentially a shock front driven
by the energy release of the reaction zones in the flow right behind it. The shock wave is very thin,
being only a few molecular mean-free-paths in width. The reaction zone may be much thicker and
can be a few mm in width under normal conditions. The shock wave and the reaction zones are
tightly coupled in a detonation wave and together move at supersonic speeds through the medium
at a few thousand meters per second.
On the other hand, deflagration is a subsonic combustion process in which a flame front
passes through the reactant mixture (or vice versa) with flame speeds from less than a few meters
per second to a few hundred meters per second, releasing the heat of reaction at a much slower
pace. In the case of scramjets, the flow may be moving at supersonic speeds, but the reaction is
still termed as a deflagration process because of the lack of shock waves. Deflagration can be
premixed or non-premixed (diffusive). For propulsion applications the premixed reaction is
preferred over improperly mixed or unmixed diffusion reactions.
Detonationv/s Deflagration

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Main components of PDE
Schematic of the PDE showing the main components
Pre-detonator:-
The pre-detonator design was chosen because of its simplicity. At the cost of a
small amount of oxygen carried on board, the pre-detonator provides an effortless means of
igniting the propane-oxygen mixture quickly with low energy sparks, and makes it possible to
transmit an accelerated detonation wave into a less energetic fuel-air mixture.
Shchelkin Spiral :-
The pre-detonator has the option of being fitted with a long Shchelkin spiral. The
spiral is welded to a flange that enables it to be bolted to the flange of the pre-detonator. The
Shchelkin spiral is used to over-drive the detonation wave so that it may be successfully
transmitted through the nozzle without decoupling.
DDT devices
The deflagration-to-detonation transition (DDT) is a process by which a deflagration flame
front is gradually accelerated to form a supersonic detonation wave. As the flame is pushed
downstream by the expansion of the burnt gases behind it, the flame front becomes curved and
wrinkled by the effects of the boundary layer in front of the flame, flame instabilities and
turbulence. As a result, the surface area of the flame grows which increases the rate of reaction of
the fuel and oxidizer. Thus, the rate of release of energy is amplified causing the flame front to be
accelerated at an even faster rate. Finally, the increased energy release leads to the formation of
one or more localized explosions and the transformation of the flame into a detonation wave.

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It has been verified that placing certain obstacles in the flow significantly reduces the DDT
run-up distance. These objects are called DDT devices. The effect that DDT devices generate is
to increase turbulence and the thickness of the boundary layer in the flow and to create instabilities
in the flame front.
The most commonly used device is the Shchelkin spiral, which is named after K.I.
Shchelkin, who discovered it, while studying the effects of wall roughness on detonation, in the
late 1930s. The Shchelkin spiral is essentially a helical spring made from thick rigid wire. The
parameters of the spiral are length, blockage ratio and pitch. The blockage ratio of the spiral or
any cylindrical DDT device is given in terms of its internal and external diameters, d and D
respectively, and thickness t , as follows.
Schematic of the shchelkin spiral
Shchelkin spiral
Nozzle:
The nozzle was designed to transmit the detonation wave with minimal loss of
velocity. It was found that larger diverging angles or abrupt transition of area cause detonation
waves to decouple, due to the excessive curvature of the detonation wave and the cooling of the
flow due to the rapid expansion.

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Main Combustion Chamber with Swirl Injector Block : -
The carbon steel collars hold pressure and optical transducer ports and contain
orifices for water to circulate through them, and also provide additional strength to the tube. The
combustor tube is covered with a layer of sheet metal in between the collars, forming a water
cooling jacket. Water is pumped in through four tubes bored into the wall of the main flange on
the left and the water exits the cooling cavity through four tubes welded to the last collar on the
right hand side of the tube. At the left hand end of the main combustor is the swirl injector
block, which has four ports through which a fuel-air mixture is pumped in.
WORKING CYCLE OF PDE
Humphrey cycle
The Humphrey cycle is a thermodynamic cycle used in pulse detonation engine. It may be
considered to be a modification of the Brayton cycle in which the constant-pressure heat
addition process of the Brayton cycle is replaced by a constant-volume heat addition process.
Hence, the ideal Humphrey cycle consists of 4 processes:
1. Reversible, adiabatic (isentropic) compression of the incoming gas. During this step
incoming gas is compressed, usually by turbomachinery. Stagnation pressure and
temperature increase because of the work done on the gas by the compressor. Entropy is
unchanged. Static pressure and density of the gas increase.
2. Constant-volume heat addition. In this step, heat is added while the gas is kept at
constant volume. In most cases, Humphrey-cycle engines are considered open cycles
(meaning that air flows through continuously), so this means that the specific volume (or
density) remains constant throughout the heat addition process. Heat is usually added by
combustion.
3. Reversible, adiabatic (isentropic) expansion of the gas. During this step incoming gas
is expanded, usually by turbomachinery. Stagnation pressure and temperature decrease
because of the work extracted from the gas by the turbine. Entropy is unchanged. Static
pressure and density of the gas decrease.
4. Constant-pressure heat rejection. In this step, heat is removed from the working fluid
while the fluid remains at constant pressure. In open-cycle engines this process usually

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represents expulsion of the gas from the engine, where it quickly equalizes to ambient
pressure and slowly loses heat to the atmosphere, which is considered to be an infinitely
large reservoir for heat storage, with constant pressure and temperature.
Efficiency of Humphrey cycle
դ = 1-𝛾
𝑇0
𝑇1
[
(
𝑇2
𝑇1
)
1
𝛾−1
𝑇2
𝑇1
−1
]
Comparison of brayton and humphrey thermodynamic cycles
Thermal efficiencies comparison ofBrayton and Humphrey cycles at different degrees of pressure

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Stages of PDE
The PDE cycle has four stages, namely
1. fill
2. combustion
3. blow down (exhaust)
4. purge.
The PDE combustion chamber is filled with fuel and oxidizer during the
fill stage. The time taken for the filling is denoted as 𝑡𝑓. When the fuel-oxidizer mixture is filled
to the required volume, the combustion stage commences when a spark (arc or any other ignition
initiator) is fired to start ignition. A detonation wave is soon created that moves through the
mixture and causes the pressure and temperature behind it to rapidly shoot up. The time taken for
the detonation wave to take shape and to move through to the end of the combustion chamber is
denoted by 𝑡 𝑐. The next stage is the blow down stage, when a series of rarefaction waves travel
upstream into the combustion chamber and reflect off the end wall, causing the high pressure burnt
gases to exit the combustion chamber at a high speed. The time taken for the blow down stage is
denoted by 𝑡 𝑏. This is then followed by the purge stage, when fresh air is blown through to clean
and cool the tube before the fill stage starts again. The time taken for purging the tube with fresh
air is denoted by 𝑡 𝑝
The purging process is very important as this cools the tube and prevents the fresh fuel
oxidizer mixture from igniting due to residual heat on entry into the combustion chamber. It also
protects the structure of the tube from heat buildup. The amount of time that the fuel-oxidizer
mixture remains within the detonation tube is known as the residence time. At higher speeds, the
residence time is very short, in the order of a few ms, and the combustion has to be initiated and
advanced to detonation in as short as 1 to 5 ms.
The total time period τ of one cycle is the sum of all the four stages, namely,
𝜏 = 𝑡𝑓+ 𝑡 𝑐+ 𝑡 𝑏+ 𝑡 𝑝
Four stages of a pulse detonation engine cycle.

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Schematic diagram of the pulse-detonation engine
This tube is sometimes referred to as a DDT (Deflagration to Detonation Transition) tube and
its job is to force the trigger charge to burn at a rate that creates a supersonic shockwave. Once it
detonates, the small charge in the trigger chamber creates a very powerful shockwave that then
hits the main air/fuel charge in the engine's secondary combustion chamber. It may sound odd that
it is possible to compress the gas in a tube which has an open end -- but the incredible speed of
the detonation shockwave means that the air/fuel simply doesn't have a chance to be pushed out
of the tube before it is compressed. As, or because it is highly compressed, the air-fuel is also
detonated by the intense heat of the shockwave.

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COMPARSIONBETWEENVARIOUS PROPULSION SYSTEMS
PDE Pulsejets Turbojets Rockets
Detonation
Combustion
(Pressure Rise)
Deflagration
Combustion
(Pressure Loss)
Deflagration
Combustion
(Pressure Loss)
Deflagration
Combustion
(Pressure Loss)
Humphrey Cycle
(Higher cycle
efficiency)
Bryton Cycle
(Lower cycle
efficiency)
Bryton Cycle
(Lower cycle
efficiency)
Bryton Cycle
(Lower cycle
efficiency)
Simple architecture Simple architecture Complex architecture Simple to Complex
architecture
Compact Compact Bulky Bulky
Low cost to acquire,
operate
Low cost High cost Low cost
Broad operating
range
Subsonic Subsonic/Low
Supersonic
Limiting operating
range
Reusable Limited reusability Limited reusability,
salt water corrosion
Limited reusability
New Technology-
higher risk
Not well developed Mature Technology-
high reliability
Mature Technology
Lightweight Lightweight Heavy Heavy
Few moving parts Few moving parts High-speed rotary
parts
Few moving parts

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FUEL INJECTION
Fuel injection is a system for admitting fuel into an engine. It
has become the primary fuel delivery system used in automotive engines, having
replaced carburetors during the 1980s and 1990s. A variety of injection systems have existed since
the earliest usage of the internal combustion engine. The primary difference between carburetors
and fuel injection is that fuel injection atomizes the fuel through a small nozzle under high
pressure, while a carburetor relies on suction created by intake air accelerated through a Venturi
tube to draw the fuel into the airstream. Modern fuel injection systems are designed specifically
for the type of fuel being used. Some systems are designed for multiple grades of fuel (using
sensors to adapt the tuning for the fuel currently used).
REQUIREMENTOF INJECTORS
Pulse detonation engine operates at certain frequency
8Hz. 𝑻𝒕𝒐𝒕𝒂𝒍 = 𝑻 𝑭𝒊𝒍𝒍 + 𝑻 𝑰𝒈𝒏𝒊𝒕𝒊𝒐𝒏 + 𝑻 𝑷𝒖𝒓𝒈𝒆 . Filling of fuel+air mixture einning consumtion is very
short in millisecond. For better performance a reliable ignition and less ignition delay we required
gasous type air fuel mixture. But when liquid fuel is used, very fine atomization is required to that
mixture of air & fuel. This can be achieved by using appropriate fuel injector. They are as straight
orifice, air assist, air blast, swirl injector.
Swirl injectors operate at relatively high pressures (4-12 MPa)
and their design enhances atomization as well as turbulence levels in the combustion chamber
for a more efficient combustion process. Instead of the round jet solid-cone structure common to
diesel injectors, the Swirl injector produces a hollow-cone spray structure by providing a swirl
rotational motion to the fuel inside the injector. Fuel injection’s critical component is fuel
injectors

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SWIRL INJECTOR
INTRODUCTION
Swirl injectors are used in liquid rocket, gas turbine, and diesel engines to improve atomization
and mixing efficiency. The circumferential velocity component is first generated as the
propellant enters through helical or tangential inlets producing a thin, swirling liquid sheet. A
gas-filled hollow core is then formed along the centerline inside the injector due to centrifugal
force of the liquid sheet. Because of the presence of the gas core, the discharge coefficient is
generally low. In swirl injector, the spray cone angle is controlled by the ratio of the
circumferential velocity to the axial velocity and is generally wide compared with non-swirl
injectors.
The basic internal geometry of the pressure swirl
injector consists of a main cylindrical body called the swirl chamber. At, or near, the upstream
end of the swirl chamber (the closed end or 'top' face) are attached the inlets. The inlets are one
or more cylindrical or rectangular channels positioned tangentially to the swirl chamber. At the
opposite end of the swirl chamber, the 'open' end, there is a conical convergence. Toward the
apex end of the cone there is a cylindrical outlet, concentric with the swirl chamber.

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Swirl injectors
In this, we are going to design Swirl Injector as per our requirements for 8Hz
and 25Hz. This injector is design on the basis of mass flow rate (𝑀̇ 𝑓𝑢𝑒𝑙) of fluid through 4
injectors. To calculate the mass flow rate we need to calculate volume, area, etc. of the tube.
After the calculation we have to design swirl injector. For designing swirl injector, we need to
calculate lengths and diameters of various parts of swirl injector ( like orifice diameter and
length, swirller length and diameter etc).
Swirler
The swirlers used to impart rotation to the airflows were of particular importance. In order to
obtain a symmetrical flow, swirlers must be machined to within very tight tolerances. Swirl
vanes may be flat, or they may be curved in a variety of ways. No matter what the type of
swirler used, however, it is essential to machine the assembly very precisely. The types of
machining operations available to produce swirlers are somewhat limited, and, if the swirlers are
assembled from separate part, the difficulty of assembling them correctly increases dramatically.
For this investigation, twisted-vane swirlers were employed, as these are compact, can be
inserted directly into an air duct, and can be machined from a single piece of stock, without any
further assembly steps. In order to machine twisted-vane swirlers, aluminum blanks were first
turned down to the precise diameters required. The blanks were initially simple cylinders, with
sections cut to two diameters: one that let them fit tightly into sleeve for the next step in the
machining process, and one that matched t +3.602he required final diameter of the swirler. The
centers of the blanks were then bored out to the required inner diameter necessary for each
swirler. A special rotating assembly, attached to a precision stepper motor, was then attached to
a vertical milling machine.

29
The most important characteristic of any swirler is
actually the outer blade angle, for the simple reason that centrifugal effects force rotating flows
outward, and the swirl properties imparted to most of the air will depend on the properties of the
swirl vanes near the outer wall of the duct. In a flat-vane swirl assembly, the local blade angle is
a constant, and does not vary with radial location. In a twisted-vane assembly, the local blade
angle, defined as the angle between the plane of the blade and the central axis of the assembly,
varies with radial location, r, due to the twisted geometry. What is clear, however, is that swirl
can be imparted very efficiently to a flow, at very small pressure drops, if these swirlers are
employed.
Internal flow of swirler
The air-core is usually seen to initiate from the outlet
orifice, where the pressure is already ambient, as one gradually increases the injection pressure.
From some observations the air-core is also seen to initiate simultaneously from the upstream
face of the swirl chamber. Thus the two ends of the air-core along the axis are not initially
joined.
The initiation of the air-core at the upstream end of the
swirl chamber is likely to be due to one or more of the following mechanisms. Firstly, as the
liquid, initially under pressure, enters the swirl chamber, then dissolved gases within the liquid
come out of suspension and are buoyed inwards toward the low pressure region on the swirl
chamber axis. Secondly, there may be an intermittent seepage of the ambient gas from the outlet
along the axis to the back face, possibly in the form of small bubbles. Figure below is a diagram
showing the air-core formation for an atomizer with a short swirl chamber and a negligible
length outlet. There is seen to be no air-core formation initiating from the upstream face in this
instance. The presence of an air-core ensures that the body of liquid within the nozzle is in the
form of an annulus and that the passage of a liquid particle through the nozzle will thus describe
a helical path.
Development of the air-core in a swirl atomizer nozzle

30
.
Liquid particle trajectory
Advantage of swirl injectors
Swirl injectors operate at relatively high pressures (4-12 MPa) and their design enhances
atomization as well as turbulence levels in the combustion chamber for a more efficient
combustion process. Instead of the round jet solid-cone structure common to diesel injectors, the
Swirl injector produces a hollow-cone spray structure by providing a swirl rotational motion to
the fuel inside the injector. The key advantage of hollow cone sprays is the high area to volume
ratio, which can lead to the required level of atomization without large penetration lengths. Swirl
injectors are used in liquid rocket, gas turbine, and diesel engines to improve atomization and
mixing efficiency. The circumferential velocity component is first generated as the propellant
enters through helical or tangential inlets producing a thin, swirling liquid sheet. A gas-filled
hollow core is then formed along the centerline inside the injector due to centrifugal force of the
liquid sheet. Because of the presence of the gas core, the discharge coefficient is generally low.
In swirl injector, the spray cone angle is controlled by the ratio of the circumferential velocity to
the axial velocity and is generally wide compared with non-swirl injectors.
Pulsating Flow with Swirl Injectors
The spray and acoustic characteristics of a gas/liquid swirl coaxial injector are studied
experimentally. Self-pulsation is defined as a pressure and flow rate oscillations by a time-
delayed feedback between liquid and gas phase. Self-pulsation accompanies very intensive
scream and this strong scream affects atomization and mixing processes. So, the spray and
acoustic characteristics of self-pulsation are different from those of general swirl coaxial spray.
The liquid and gas velocity is selected as the variables of injection conditions and recess length
is chosen as the variable of geometric conditions. By shadow photography technique, spray
patterns are observed in order to investigate the macroscopic spray characteristics and determine
the onset of self-pulsation. For acoustic characteristics, a PULSE System was used. Using He-

31
Ne laser and photo detector system frequencies of spray oscillations are measured. And self-
pulsation boundary with injection conditions and recess length is obtained. From the
experimental results, the increase of recess length leads to the rapid increase of the sound
pressure level. And characteristic frequency is mainly dependent on the liquid velocity and
linearly proportional to the liquid velocity. The frequency of spray oscillation is the same as that
of the acoustic fields by self-pulsation.
Pulsating flow with swirl injector

32
SPRAY FORMATION
INRODUCTION
Sprays are an important constituent of many natural and technological processes and range in
scale from the very large dimensions of the global air-sea interaction and the dynamics of
spillways and plunge pools to the smaller dimensions of fuel injection and ink jet systems. In
general, sprays are formed when the interface between a liquid and a gas becomes deformed and
droplets of liquid are generated. These then migrate out into the body of the gas. Sometimes the
gas plays a negligible role in the kinematics and dynamics of the droplet formation process; this
simplifies the analyses of the phenomena. In other circumstances the gasdynamic forces
generated can play an important role. This tends to occur when the relative velocity between the
gas and the liquid becomes large as is the case, for example, with hurricane-generated ocean
spray.
In many important technological processes, sprays are formed by the breakup of a liquid jet
injected into a gaseous atmosphere. One of the most important of these, is fuel injection in
power plants, aircraft and automobile engines and here the character of the spray formed is
critical not only for performance but also for pollution control. Consequently much effort has
gone into the design of the nozzles (and therefore the jets) that produce sprays with desirable
characteristics. Atomizing nozzles are those that produce particularly fine sprays.
a) Spray formation
Combustion of liquid fuels differs from the combustion of gaseous fules in that a liquid fuel
must be vaporized and then combusted .This additional step adds a significant complication to

33
the combustion process.In the analysis of gaseous fuel combustion systems ,we were concerned
about the energy density of the fuel,the reaction rate ,the heat release rate ,the flame temperature
and the flame speed –all of which are coupled together .In the analysis of the liquid fuel
combustion systems ,we are again concerned about the energy density of the fuel ,the reaction
rate ,the heat release rate,the flame tempersature and the flame speed ;but the rate controlling
phenomenon is the evaporation of the fuel. Spray can be formed in a number of ways .Most
commonly liquid fuel spray are formed by pressurized jet atomization.In pressurized jet
atomization a spray is formed by pressurizing a liquid and forcing it through an orifice at a high
velocity to the surrounding air or gas.Alternatively ,air blast atomization produces a spray by
impinging a high velocity air flow on a relatively slow-moving liquid jet.
As a liquid emerges from an orifice into a gas ,the breakup
mechanism maybe visualized sequentially beginning with streching or narrowing of the liquid
followed by the apperence of ripples ,protuberances and ligaments in the liquid ,which leads to
the raptd collapse of the liquid into droplets.further breakup then occurs due to the vibration and
shear of the droplets and finally some agglomeration of the droplets occurs due to the collisions
if the spray is not dilute .
The spray formation process is characterized by the three dimensionless groups.These are
 Jet Reynold Number (the ratio of inertia force to viscous force )
Re =
𝜌𝑉𝑑
𝜇
 Jet weber number ( the ratio of inertia force to surface tension force)
We =
𝜌𝑉𝑑
𝜎
 Ohnesorge number ( the ratio of viscous force to surface tension force )
Oh =
𝜇
√𝜌𝜎𝑑

34
Effectof swirl in a spray formation.
When swirl is induced in the liquid as it flows into an orifice ,the jet forms a wider conical sheet
and breaks up in a similar wave like manner as in a plain jet .The spray from a plain or swirl
type orifice penetrates a certain distance before coming to rest in quiescent air.the three
dimensionless numbers above are useful in formating emperical relationships for droplet size
,spray angle and penetration .
Droplet size distribution
Droplet size measurements in spray are made using various optical techniques and by
convntional methods such as cup method for meauring MMD (mass median diameter).A short
laser can be used to penetrate the spray and illuminate a high digittal camera screen.Digital
images from the camera are then transferred to a computer and particle sizing software is used to
analyze the images obtained in order to build up a distribution of diameters.
There are five different mearsurements of diameter that are commonly used to describe the
average size of a distribution of droplet in a simple way.These are :-
1.Most probable droplet diameter
2.Mean diameter
3.Area mean diameter
4.Volume mean diameter
5.Sauter mean diameter

35
Mostprobable droplet diameter is the droplet diameter with the largest fraction of
droplets.
Meandiameter(MMD)S is the average diameter of the group of droplets based on
the fraction of droplets at each diameter.
𝐝 𝟏 = ∑ 𝐝𝐢∆𝐍𝐢
∞
𝐢=𝟏
Area mean diameter (AMD) is the average diameter based on the fraction of droplets
with a given surafce area .
𝐝 𝟐 = ∑ (√𝐝 𝟐
𝐢∆𝐍𝐢
∞
𝒊=𝟏
)
Volume mean diameter (VMD) is the average diameter based on thefraction of the
droplets with given volume.
𝐝 𝟑 = ∑ (∛𝐝 𝟑
𝐢∆𝐍𝐢
∞
𝒊=𝟏
)
Sauter mean diameter (SMD) is used in a number of spray models.SMD is the VMD
divided by AMD
𝐝 𝟑𝟐 =
∑ ( √ 𝐝 𝟑
𝐢∆𝐍𝐢
𝟑
)
∞
𝒊=𝟏
∑ (√𝐝 𝟐
𝐢∆𝐍𝐢)
∞
𝒊=𝟏

36
CALCULATION AND DESIGN PART
Calculation for 8Hz
Given data of 1 tube :-
Length of the tube, L = 1m
Diameter of the tube, d = 4inchs = 96 mm
Volume of the tube, 𝑉 =
𝜋
4
. 𝑑2
. L
𝑉 =
𝜋
4
. (
96
1000
)
2
.1
V = 7.239 x10−3
𝑚3
For time calculation: -
We know that the PDE is operating at 8Hz frequency
i.e. 8 cycles in 1sec
or 1 cycle in =
1000
8
= 125 ms
1 complete cycle consists of Filling, Ignition and Purging
. .̇ 𝑇𝑡𝑜𝑡𝑎𝑙 = 𝑇𝐹𝑖𝑙𝑙 + 𝑇𝐼𝑔𝑛𝑖𝑡𝑖𝑜𝑛 + 𝑇𝑃𝑢𝑟𝑔𝑒
100% = 60% + 30% + 10%
60% of one cycle Filling time
0.6 x 125 = 75 ms

37
Now,
Volume flow rate (𝑉̇ ) to fill the tube =
𝑉𝑜𝑙𝑢𝑚𝑒
𝑇𝑖𝑚𝑒
𝑉̇ =
7.239 𝑥 10−3
0.075
𝑉̇ = 0.09652 𝑚3
/𝑠𝑒𝑐
We know,
Density of Fuel = 780 kg/𝑚3
Density of Air = 1.15 kg/𝑚3
Density of Air/Fuel mixture = 1.2257 kg/𝑚3
Temperature = 303 K
Now,
Mass flow rate (𝑴̇ ) = Volume flow rate (𝑽̇ ) x Density of Air/Fuel mixture (ρ)
𝑀̇ = 0.09652 x 1.2257 kg/sec
𝑀̇ = 0.11830 kg/sec
𝑀̇ 𝑡𝑜𝑡𝑎𝑙 = 𝑀̇ 𝑎𝑖𝑟 + 𝑀̇ 𝑓𝑢𝑒𝑙
By Stoichiometry Ratio, we know mixing ratio of air/fuel for combustion process,
i.e. Air: Fuel = 15:1
..̇
𝑀̇ 𝑎𝑖𝑟
𝑀̇ 𝑓𝑢𝑒𝑙
= 15
𝑀̇ 𝑓𝑢𝑒𝑙 =
𝑀̇ 𝑎𝑖𝑟
15
𝑀̇ 𝑡𝑜𝑡𝑎𝑙 = 𝑀̇ 𝑎𝑖𝑟 +
𝑀̇ 𝑎𝑖𝑟
15
𝑀̇ 𝑎𝑖𝑟 =
𝑀̇ 𝑡𝑜𝑡𝑎𝑙
(1+
1
15
)
=
0.11830
(1+
1
15
)
𝑀̇ 𝑎𝑖𝑟 = 0.11085 kg/sec
= 110.85 g/sec
..̇ 𝑀̇ 𝑓𝑢𝑒𝑙 = 7.39 g/sec

38
 To calculate main orifice diameter (𝒅 𝒐) for swirl injector at 8Hz.
From above calculation, we find the mass flow rate (𝑀̇ 𝑓𝑢𝑒𝑙) of fuel through 4 injectors = 7.39
g/sec
Now, mass flow rate (𝑀̇ 𝑓𝑢𝑒𝑙) of fuel through 1 injector =
7.39
4
= 1.84 g/sec
Formula to be used: 𝑴̇ 𝒇𝒖𝒆𝒍 = 𝑪 𝒅.A.√ 𝟐 𝚫𝐏𝝆
Where, 𝐶 𝑑 = Discharge Coefficient
A = Area of Orifice
ΔP = Pressure difference
𝜌 = Density of fluid
Given: -
𝐶 𝑑 = 0.28-0.30
ΔP = 3 to 4 bar
𝜌 = 780 kg/𝑚3
A =?
Area (A) to be calculated:
A =
𝑀̇ 𝑓
𝐶 𝑑.√2ΔP𝜌
=
0.00184
0.28𝑥√2𝑥3𝑥105 𝑥780
A = 3.0376 x10−7
𝑚2
..̇ A =
𝜋
4
. 𝑑 𝑜
2
𝑑 𝑜 = 0.621 mm

39
Designcalculation
1st Rule :-
𝑫 𝒔
𝒅 𝒐
= 3.3
Where, Ds = Diameter of Swirl
𝑑 𝑜 = Diameter of Orifice
Ds= 3.3𝑑 𝑜
= 3.3 x 0.621
Diameter of Swirl, Ds = 2.0493 mm
2nd Rule :-
𝑳 𝒔
𝑫 𝒔
= 2.75
Where, Ls = Length of Swirl
Ds= Diameter of Swirl
Ls = 2.75Ds
= 2.75 x 2.0493
Length of Swirl, Ls = 5.635 mm

40
3rd Rule :-
𝒍 𝒐
𝒅 𝒐
= 0.5
Where, 𝑙 𝑜 = Length of main Orifice
𝑙 𝑜 = 0.5𝑑 𝑜
= 0.5 x 0.621
Length of Orifice, 𝑙 𝑜 = 0.3105 mm
But it is not feasible as per manufacturing point of view. So,
Length of Orifice, 𝑙 𝑜 ≈ 2 mm
4th Rule :-
𝑳 𝑷
𝑫 𝑷
= 1.5
𝑳 𝑷 = 1.5 𝑫 𝑷 ………(1)
we also know that,
Area of swirler , 𝑨 𝒑 = 𝑳 𝑷 x 𝑫 𝑷
Using (1), we get
𝑨 𝒑 = 1.5 𝑫 𝑷 x 𝑫 𝑷 ……….(2)

41
And
𝑪 𝒅 = 𝟎. 𝟑𝟓 (
𝑨 𝑷
𝑫 𝒔 𝒅 𝒐
)
𝟎.𝟓
. (
𝑫 𝒔
𝒅 𝒐
)
𝟎.𝟐𝟓
Given: -
Discharge Coefficient, 𝐶 𝑑 = 0.28-0.30
Diameter of Swirl, 𝐷 𝑠 = 2.172
Diameter of Orifice, 𝑑 𝑜 = 0.658
. .̇ 𝑨 𝑷 = 0.448 𝑚𝑚2
By putting this value of , 𝑨 𝑷 in (2) we get
𝐷 𝑃 = 0.546 mm
𝐿 𝑃 = 1.5 𝐷 𝑃
𝐿 𝑃 = 1.5 x 0.546
𝐿 𝑃 = 0.298 mm

42
Calculation for 25Hz
Lenghth of the tube, L = 1m
𝜋
4
. 𝑑2
. L
𝑉 =
𝜋
4
. (
96
1000
)
2
.1
V = 7.23 x 10−3
𝑚3
For timecalculation:-
We know that the PDE is operating at 25Hz frequency
i.e 25 cycles in 1sec
or 1 cycle in =
1000
25
= 40 ms
1complete cycle consists of Filling, Ignition and Purging
100% = 60% + 30% + 10%
0.6 x 40 = 24 ms

43
Now,
𝑇𝑖𝑚𝑒
𝑉̇ =
7023 𝑥 10−3
0.024
𝑉̇ = 0.3012 𝑚3
/𝑠𝑒𝑐
We know,
Temperature = 303 K
Now,
Mass flow rate (𝑀̇ ) = Volume flow rate (𝑉̇ ) x Density of Air/Fuel mixture (ρ)
𝑀̇ = 0.3012 x 1.2257 kg/sec
𝑀̇ = 0.3692 kg/sec
..̇
𝑀̇ 𝑎𝑖𝑟
= 15
𝑀̇ 𝑎𝑖𝑟
15
𝑀̇ 𝑎𝑖𝑟
15
(1+
1
15
)

44
=
0.3692
(1+
1
15
)
𝑀̇ 𝑎𝑖𝑟 = 0.34605 kg/sec
= 346.05 g/sec
..̇ 𝑀̇ 𝑓𝑢𝑒𝑙 = 23.07 g/sec
 To calculate main orifice diameter (𝒅 𝒐) for swirl injector at 8Hz.
From above calculation, we find the mass flow rate (𝑀̇ 𝑓𝑢𝑒𝑙) of fuel through 4 injectors =
25.73 g/sec
23.07
4
= 5.767 g/sec
A = Area of Orifice
Area(A) to be calculated:
A =
𝑀̇ 𝑓
=
0.005767
0.28𝑥√2𝑥3𝑥105 𝑥780
A = 9.520 x10−7
𝑚2
..̇ A =
𝜋
4
. 𝑑 𝑜
2
𝑑 𝑜 = √4 𝑥 9.520 𝑥 10−7
3.142
𝑑 𝑜 = 1.10 mm

45
Designcalculation
1st Rule :-
𝑫 𝒔
𝒅 𝒐
= 3.3
𝑑 𝑜= Diameter of Orifice
Ds= 3.3𝑑 𝑜
= 3.3 x 1.10
2nd Rule :-
𝑳 𝒔
𝑫 𝒔
= 2.75
Ls = 2.75Ds
= 2.75 x 3.63

46
3rd Rule :-
𝒍 𝒐
𝒅 𝒐
= 0.5
𝑙 𝑜 = 0.5𝑑 𝑜
= 0.5 x 1.10
4th Rule :-
𝑳 𝑷
𝑫 𝑷
= 1.5
𝑳 𝑷 = 1.5 𝑫 𝑷 ………(1)
we also know that,
Area of swirler, 𝑨 𝒑 = 𝑳 𝑷 x 𝑫 𝑷

47
Using (1), we get
𝑨 𝒑 = 1.5 𝑫 𝑷 x 𝑫 𝑷 ……….(2)
And
𝑪 𝒅 = 𝟎. 𝟑𝟓 (
𝑨 𝑷
𝑫 𝒔 𝒅 𝒐
)
𝟎.𝟓
. (
𝑫 𝒔
𝒅 𝒐
)
𝟎.𝟐𝟓
Given:-
. .̇ 𝑨 𝑷 = 1.407 𝑚𝑚2
𝑫 𝑷 = 0.968 mm
𝑳 𝑷 = 1.5 𝑫 𝑷
𝑳 𝑷 = 1.5 x 0.968
𝑳 𝑷 = 1.452 mm.

48
Calculation for 50 Hz
Lenghth of the tube, L = 1m
𝜋
4
. 𝑑2
. L
𝑉 =
𝜋
4
. (
96
1000
)
2
.1
V = 7.23 x10−3
𝑚3
For time calculation:-
We know that the PDE is operating at 50 Hz frequency
i.e 50 cycles in 1sec
or 1 cycle in =
1000
50
= 20 ms
1complete cycle consists of Filling, Ignition and Purging
100% = 60% + 30% + 10%
0.6 x 20 = 12 ms
Now,
𝑇𝑖𝑚𝑒
𝑉̇ =
7.23𝑥10−3
0.012
𝑉̇ = 0.6025 𝑚3
/𝑠𝑒𝑐

49
We know,
Temperature = 303 K
Now,
Mass flow rate (𝑀̇ ) = Volume flow rate (𝑉̇ ) x Density of Air/Fuel mixture (ρ)
𝑀̇ = 0.6025 x 1.2257 kg/sec
𝑀̇ = 0.7384 kg/sec
..̇
𝑀̇ 𝑎𝑖𝑟
= 15
𝑀̇ 𝑎𝑖𝑟
15
𝑀̇ 𝑎𝑖𝑟
15
(1+
1
15
)
=
0.7384
(1+
1
15
)
𝑀̇ 𝑎𝑖𝑟 = 0.69225 kg/sec
= 692.25 g/sec
..̇ 𝑀̇ 𝑓𝑢𝑒𝑙 = 46.15 g/sec

50
To calculate main orifice diameter (𝒅 𝒐) for swirl injector at 8Hz.
From above calculation, we find the mass flow rate (𝑀̇ 𝑓𝑢𝑒𝑙) of fuel through 4 injectors =
46.15 g/sec
46.15
4
= 11.53 g/sec
A = Area of Orifice
Given:-
𝐶 𝑑 = 0.28-0.30
ΔP = 3 to 4 bar
𝜌 = 780 kg/𝑚3
A = ?
Area(A) to be calculated:
A =
𝑀̇ 𝑓
=
11.53
0.28𝑥√2𝑥3𝑥105 𝑥780 𝑥1000
A = 19.03x10−7
𝑚2
..̇ A =
𝜋
4
. 𝑑 𝑜
2
𝑑 𝑜 = 1.55 mm

51
Designcalculation
1st Rule :-
𝑫 𝒔
𝒅 𝒐
= 3.3
𝑑 𝑜= Diameter of Orifice
Ds= 3.3𝑑 𝑜
= 3.3 x 1.55
2nd Rule :-
𝑳 𝒔
𝑫 𝒔
= 2.75
Ls = 2.75Ds
= 2.75 x 5.115

52
3rd Rule :-
𝒍 𝒐
𝒅 𝒐
= 0.5
𝑙 𝑜 = 0.5𝑑 𝑜
= 0.5 x 1.55
4th Rule :-
𝑳 𝑷
𝑫 𝑷
= 1.5
𝑳 𝑷 = 1.5 𝑫 𝑷 ………(1)
we also know that,
Area of swirler, 𝑨 𝒑 = 𝑳 𝑷 x 𝑫 𝑷
Using (1), we get
𝑨 𝒑 = 1.5 𝑫 𝑷 x 𝑫 𝑷 ……….(2)

53
And
𝑪 𝒅 = 𝟎. 𝟑𝟓 (
𝑨 𝑷
𝑫 𝒔 𝒅 𝒐
)
𝟎.𝟓
. (
𝑫 𝒔
𝒅 𝒐
)
𝟎.𝟐𝟓
Given:-
. .̇ 𝑨 𝑷 = 2.028 𝑚𝑚2
𝑫 𝑷 = 1.162 mm
𝑳 𝑷 = 1.5 𝑫 𝑷
𝑳 𝑷 = 1.5 x 1.162
𝑳 𝑷 = 1.74 mm.

54
HELIX ANGLE FOR SWIRLER
Helix angle: - Helix angle is the angle between any helix and an axial line on its right, circular
cylinder or cone.
FORMULA :-
tan ∅ =
𝑃 𝑋 𝑁
𝜋 𝑋 𝐷
∅ = HELIX ANGLE
∅ = tan−1
(
𝑃 𝑋 𝑁
𝜋 𝑋 𝐷
) P = PITCH
∅ = tan−1
(
𝐿
𝜋 𝑋 𝐷
) N = No.Of STARTS
D = PITCH DIAMETER
Also,
𝒓 𝒎 = 𝒎𝒆𝒂𝒏 𝒓𝒂𝒅𝒊𝒖𝒔 𝒐𝒇 𝒔𝒄𝒓𝒆𝒘 𝒕𝒉𝒓𝒆𝒂𝒅
l = lead of the screw thread

55
Calculations :-
1. For 8 Hz :- Given
Pitch (length of swirler ) = 5.635 mm
Pitch diameter = 2.0493 mm
N = 2
Helix angle (∅) = tan−1
(
5.635 𝑋 2
3.142 𝑋 2.0493
)
= 60.26°
2. For 25 Hz :- Given
N = 4
(
9.982 𝑋 4
3.142 𝑋 3.63
)
= 74.05°
3. For 50Hz :- :- Given
N = 4
(
41.06 𝑋 4
3.142 𝑋 5.115
)
= 74.05°

56
Observations :-
S.No. Input Parameters 8 Hz 25 Hz 50 Hz
1. Mass flow rate of fuel through
4 injector, (𝑀̇ 𝑓𝑢𝑒𝑙)
7.39 g/sec 23.07 g/sec 46.15 g/sec
2. Mass flow rate of fuel through
1 injector, (𝑀̇ 𝑓𝑢𝑒𝑙)
1.84 g/sec 5.767 g/sec 11.53 g/sec
3. Pressure, P 3 bar 3 bar 3 bar
4. Density of fluid, 𝜌 780 kg/𝑚3
780 kg/𝑚3
780 kg/𝑚3
5. Density of air 1.5 kg/𝑚3
1.5 kg/𝑚3
1.5 kg/𝑚3
6. Density of mixture 1.2257 kg/𝑚3
1.2257 kg/𝑚3
1.2257 kg/𝑚3
7. Discharge Coefficient, 𝐶 𝑑
(assume)
0.28 0.28 0.28
8. Area, A (𝑚2
) 3.0376
x10−7
𝑚2
9.520 x10−7
𝑚2 19.03 x10−7 𝑚2
S.N
o.
DESIGN
PARAMET
ERS
8Hz 25Hz 50 Hz
1. Diameter of
Orifice, do
0.621 1.10 1.55
2. Swirl
Diameter,
Ds
Ds
do
= 3.3
Ds= 2.0493 mm
Ds
do
= 3.3
Ds= 3.63 mm
Ds
do
= 3.3
Ds= 5.115 mm
3. Swirler
Length, Ls
Ls
Ds
= 2.75
Ls= 5.635 mm
Ls
Ds
= 2.75
Ls= 9.982 mm
Ls
Ds
= 2.75
Ls=14.06 mm
4. Main
Orifice
Length, lo
lo
do
= 0.5
lo ≈ 2 mm (assumed)
lo
do
= 0.5
lo ≈ 2 mm (assumed )
lo
do
= 0.5
lo ≈ 2 mm (assumed )
5. Area of
Swirler part,
AP
Cd
= 0.35(
AP
Dsdo
)
0.5
. (
Ds
do
)
0.25
AP = 0.448 mm2
Cd
= 0.35(
AP
Dsdo
)
0.5
. (
Ds
do
)
0.25
AP = 1.407 mm2
Cd
= 0.35(
AP
Dsdo
)
0.5
. (
Ds
do
)
0.25
AP =2.028 mm2
6. Length of
Swirler part,
LP
LP
DP
= 1.5
LP = 0.819 mm
LP
DP
= 1.5
LP = 1.452 mm
LP
DP
= 1.5
LP = 1.74 mm
7. Diameter of
Swirler part,
DP
LP
DP
= 1.5
DP = 0.546 mm
LP
DP
= 1.5
DP = 0.968 mm
LP
DP
= 1.5
DP = 1.162 mm

57
Solid work Model of Swirl Injector
From the above observation and calculations, we have got the dimensions and
measurements of Swirl Injectors and hence further we can draw the components of
Swirl Injector .
1.
(a) Injector body (solid model)
(b) Injector Body (fabricated part)

58
2.
(a) Holder (solid model)
(b) Holder (fabricated part)

59
3.
(a) Adaptor (solid model)
(b) Adapter (fabricated part)

60
4.
(a) Swirler (solid model)
(b) Swirler ( fabricated part)

61
ASSEMBLY PARTS OF SWIRL INJECTOR
INJECTOR BODYSWIRLERHOLDERADAPTOR
SWIRL INJECTORALONGWITH
CONNECTOR

62
EXPERIMENTAL SET-UP FOR SWIRLINJECTOR
For determining various parameters related to swirl injector ,I have dseigned an experimental set
up for it.The parameters such as mass median diameter (MMD) of the spray,spray cone angle
and mixing of the inline swirl injectors.
SET –UP
Material used :- Plywood
It consist of the following parts:-
Fuel manifold
Fuel line
Swirl injector
Cups for collection of fuel FUEL
MANIFOLD
CUPS SWIRL INJECTOR
FUEL LINE
WASTE FUEL
COLLECTION
AREA

63
OBJECTIVES OF THE SET - UP BOX
1.SPRAY PATTERN
2.CAPACITY
3.SPRAY IMPACT
4.SPRAY ANGLE
5.DROP SIZE
We have calculated spray cone angle ,drop size and spray impact.
 SPRAY CONE ANGLE :- The spray angle diverges or converges with respect to the
vertical axis. As illustrated in the figure below, the spray angle tends to collapse or
diverge with increasing distance from the orifice. Spray coverage varies with spray
angle. The theoretical coverage, C, of spray patterns at various distances may be
calculated with the equation below for spray angles less than 180 degrees. The spray
angle is assumed to remain constant throughout the entire spray distance. Liquids more
viscous than water form smaller spray angles, or solid streams, depending upon nozzle
capacity, spray pressure, and viscosity. Spray angles are typically measured using
optical or mechanical methods.

64
Mathematical formula for spray cone angle
C = theoretical coverage
D = spray distance
𝜃 = spray cone angle
According to our calculations ,the spray cone angle measured is 60deg.
SPRAYCONE ANGLE
60 DEG

65
PROCEDUREFOR CALCULATING MASS MEDIAN DIAMETER (MMD)
First marking has to be done on the bottom of the cups from 1 to 12.
Now weigh the empty cups.
Cup number Empty weight (gm)
1 2.84
2 2.82
3 2.84
4 2.82
5 2.83
6 2.83
7 2.81
8 2.80
9 2.82
10 2.79
11 2.81
12 2.80
cup arrangement in set up box

66
Now we have to arrange the cups under the swirl injector and collects the fuel .Again we
have to weigh the cups.
Cup number Filled weight (gm)
1 6.04
2 7.12
3 6.04
4 5.72
5 6.04
6 5.43
7 5.01
8 6.6
9 7.3
10 5.99
11 6.81
12 6.9
droplets collected in different cups

67
Now calculating the wieght of the fuel collected in the cups alongwith the remaining fuel
which is not collected in the cups.
Cup
number
Filled weight Empty weight Collected weight
(filled – empty)
1 6.04 2.84 3.2
2 7.12 2.82 4.3
3 6.04 2.84 3.2
4 5.72 2.82 2.9
5 6.04 2.83 3.2
6 5.43 2.83 2.6
7 5.01 2.81 2.2
8 6.6 2.80 3.8
9 7.3 2.82 4.5
10 5.99 2.79 3.2
11 6.81 2.81 4.0
12 6.9 2.80 4.1
Time duration of flow = 20 sec
Therefore average mass flow rate of of each cup is calculated by
m =
𝑐𝑜𝑙𝑙𝑒𝑐𝑡𝑒𝑑 𝑤𝑒𝑖𝑔ℎ𝑡
𝑡𝑖𝑚𝑒 𝑑𝑢𝑟𝑎𝑡𝑖𝑜𝑛
Cup number Collected
weight(gm)
(filled – empty)
Time
duration
(Sec)
Mass flow rate
in each
cup(g/s)
1 3.2 20 0.16
2 4.3 20 0.21
3 3.2 20 0.16
4 2.9 20 0.14
5 3.2 20 0.16
6 2.6 20 0.13
7 2.2 20 0.11
8 3.8 20 0.19
9 4.5 20 0.22
10 3.2 20 0.16
11 4.0 20 0.20
12 4.1 20 0.20

68
Now to calculate the droplet diameter we have to use the given formula
Formula to be used: m= 𝐶𝑑.A.√2ΔP𝜌
A = Area of droplet
By putting the values we have formed a final equation in the form of mass flow rate and
diameter of droplet
𝑑𝑖 = √ 𝑚 𝑥 0.9225
Cup number Mass flow rate in
each cup(g/s)
Droplet Diameter
(microns)
1 0.16 39
2 0.21 45
3 0.16 39
4 0.14 37
5 0.16 39
6 0.13 35
7 0.11 32
8 0.19 42
9 0.22 46
10 0.16 39
11 0.20 43
12 0.20 44
Now,
Mass median diameter will be the average of these droplet diamters.
MMD =
𝑠𝑢𝑚 𝑜𝑓 𝑡ℎ𝑒 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟𝑠
𝑛𝑜.𝑜𝑓 𝑐𝑢𝑝𝑠
=
39+45+39+37+39+35+32+42+46+39+43+44
12
=
480
12
= 40 microns
The MMD value which is calculated by this experiment is 40 microns.but this experiment will
be performed once again to achieve the value of 10 microns with more acurate results.

69
MIXING OF THE SPRAY
From this set up box ,we can also check the proper mixing pattern of the spray .For this mixing
,we have to intall the swirl injectors in line and fuel supply will be given.We will then see the
mixing profermance of a single spray with the adjacent sprays.
This is done because the swirl injectors are to be placed inline in the pulse detonation engine.
mixing pattern of spray

70
CONCLUSION
To replace other injectors such as ( air blast ,orifice ,etc) used in the pulse detonation engine ,we
have studied the concept of swirl injector. The swirl injector will increase the atomisation of the
fuel by adding the centrifugal force of the swirler and thus inreasing the efficiency of the
engine.We have worked in a steady mode with this swirl injector but still the research is to be
done on pulsating mode ie. It has to worked on different frequencies such as 8 Hz ,25 Hz and 50
Hz.
I have stuided the basic concept of swirl injector and designed it .For testing this swirl injector I
have also designed a set up box for it in which various parameters such as spray cone angle
,mass median daimeter (MMD) and mixing is done.Still the results are not accurate but more
research is to be done on this swirl injector for reaching the exact results.
REFERENCES
1.Kailasanath, K. “Recent Developments in the Research on Pulse Detonation Engines,” AIAA
Paper 2002-0470, AIAA 40th Aerospace Sciences Meeting, Reno, NV, 14–17 Jan. 2002.
2. Munipalli, R., Shankar V., Wilson, D.R., and Lu F.K., “Preliminary design of a pulse
detonation based combined cycle engine,” ISABE Paper 2001–1213, 15th International
Symposium on Air breathing Engines, Bangalore, India, 2–7 Sep. 2001.
3.Stanley, Steven B., “Experimental Investigation of Factors Influencing the Evolution of a
Detonation Wave,” Master's Thesis, Department of Mechanical and Aerospace Engineering,
The University of Texas at Arlington, Arlington, TX, 1995.
4. Borman, G. L. and Ragland, K.W., “Combustion Engineering,” McGraw Hill, 1998.
5. Owens, M., Segal, C. and Auslender, A.H., “Effects of Mixing Schemes on Kerosene
Combustion in a Supersonic Airstream,” Journal of Propulsion and Power, Vol. 13, No. 4, Jul.-
Aug. 1997.
6.H . Lefebvre, Atomization and Sprays, Hemisphere, Washington, D .C., 1989 .
7. N . K. Rizk and A. H. Lefebvre, Internal Flow Characteristics of Simplex Swirl Atomizers ,
AIAA J. Propulsion, vol . 1, no. 3, pp. 193-199, 1985 .
8. Anderson, D. N., "Effects of Fuel-Injector Design on Ultra-Lean Combustion Performance,"
NASA-TM-82624, 1981.

71
APPENDIX

72
PICTURES OF SET UP BOX.
Set up box fitted with manifold
Spray cone angle test
Cup arrangements for MMD

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