1. FAMILARIZATION ON - ENGINE AND
THEIR PARTS & WORK ON FAILURES
OF PNEUMATIC CYLINDER IN TVC
PNEUMATIC CYLINDER
GUIDED BY
MR. RADHA GOBINDA MISHRA (R.G.MISHRA)
& Manager (620-Assembly Shop) SED
MR.SHIBENDU SEN
Dy. Manager (620-Assembly Shop) SED
SUBMITED BY:- KAMALAKANTA MOHAPATRA (VT NO-1902)

3. CONTAINS
SL. NO Contains DESCRIPTION
1
2
3
4
5
6
INTRO
AL31FP
Feature and information
All Parts
AGGREGATES
Research on failure of pneumatic
cylinder
AND the jet engines invention
history
Shows schematic detailed and
short information about AL31FP
engine
Describes about the engines
features, Limit, Information in
detailed
Described parts of the AL31fp
engines and detailed information
about them
The various equipment which
controls the engine for its best
performance and safety are all
discussed here. (avionics)
An additional with the project
works here the failures of the
pneumatic cylinder A VJN
assembly part failure has been
described after proper
investigation.

4. INTRODUCTION TO HAL AND TO PROJECT
Hindustan Aeronautics Limited is the one of the Asia premier organization of
Present Aerospace industry. HAL Koraput division is manufacturing and
overhauling unit for various aero engines.
As per the present scenario the division manufactures only
AL31FP engine for
SUKHOI- 30MKI aircraft.
It overhauls
AL31FP for SUKHOI -30 MKI
RD33 for MIG -29
R29B for MIG -27M
R25 for MIG -21BISON
All the above stated engines comes under turbojet engine category which is a
Type of jet engine. Our project work is carried here for 5 weeks covering all the
sections from research and development section to final dispatch section in order to
acquire industrial oriented procedure. This project helps the people to understand
from the basics of Jet engine because we initially covered a section JET ENGIENS
in order to give the knowledge of JET ENGINE, its components and its working.
Then next phase of our work is Find a failure reason research work on pneumatic
cylinder find out failure reason and state with probable solution with definition
Finally phase we covered our work with the old section of various other
jets(MIG)and other such as R series engine and in test section where we got much
more knowledge. Like industrial managements and other practical knowledge
which we face only theoretically in our class notebooks, Books
JET ENGINES
DEFINITION OF JET ENGINE:
Small cross sectional area (nozzle) by jet propulsion which creates thrust in
Accordance

5. This broad definition includes a turbojets, turbofans, rockets, ramjets and
Pulsejets types of jet engines etc.
HISTORY AND INVENTION: Dr. Hans von Ohain and Sir Frank
Whittle are both recognized as being the co-inventors of the jet engine. Each
Worked separately and knew nothing of the other's work.
A young Royal Air Force man, Sir Frank Whittle, had presented to the Air
Ministry a design for a jet engine in October 1929. They were unimpressed and
rejected his idea. Regardless of this setback, Whittle still patented his "turbojet
engine" he developed his ideas further and on 16 January 1930 in England,
Whittle submitted his first patent (granted in 1932) and first to register patent. In
1936, he set up a company called Power Jets Ltd. In 1937, using newly
available alloys that were strong and light, he produced the first viable jet
engine to be successfully tested in a laboratory and first flew in 1941. Dr.Hans
von Ohain, a German scientist was granted a patent for his turbojet engine in
1936 and flew his Jet aircraft in 1939.
Sir Frank Whittle (left) and Dr.Hans von Ohain(right)

6. All jet engines works on BRAYTON thermodynamic cycle developed by
George Brayton but, patented by Englishman John Baber in 1791.It is also
Sometimes known as the Joule cycle. It is a constant pressure cycle
Accomplishing the same operations as in Otto cycle, but all operations are
Continuously with uninterrupted flow of power.
Ideal Brayton cycle:
Processes of ideal Brayton cycle:-
1-2 isentropic process - ambient air is drawn into the compressor,
where it is pressurized.
2-3 Isobaric process - the compressed air then passes through a
combustion chamber, where fuel is burned, heating that air a
constant-pressure process, since the chamber is open to flow in and
out.
3-4 isentropic process - the heated, pressurized air then gives up its
energy, expanding through a turbine (or series of turbines). Some of the
work extracted by the turbine is used to drive the compressor.
4-1 Isobaric process - heat rejection (in the atmosphere).
Pressure - Volume and Temperature entropy diagrams

7. AL31FP
AL 31 FP engine is designed and developed by Lyulka, of Russian based
company and now HAL is manufacturing the engines under license.
AL 31 FP engine, stands for
A- Name of designer- Arkhip Mikhailovich Lyulka
L- Name of company-Lyulka, now NPO Saturn
31-stands for series
F-stands for after burner (Farsa in Russian language)
P-stands for thrust vectoring nozzle (Povorothoye in Russian language)
The AL 31 FP is a turbojet engine with having a special features of Variable
LPCR guide vanes, by-pass duct from LPCR and variable HPCR stator blades
of Stages 1, 2, 3 and thrust vector nozzle by tilting angle of 14 degree.
WARNING- This figure is a copyright contain from HAL
COURTICY of H.A.L, used by permissions only I have not created
this figure or linked with it in any matter .

8. Engine features and technical information
Engine Information:-
Each of AL-31FP engine weights 1570 KG. It have an afterburner equipped all mode TVC
controller. The (OTB)
overhaul time between (OEM) original equipment manufacturer for maintenance 500 hours
and life span of engine is 2000 hours there are totally 645 parts, 202 assembly & 40 mandatory
parts each engine have 2710 blades. The nozzles are mounted 32 degrees outward to
longitudinal engine axis (in the horizontal plane) and can be deflected ±15 degrees in one
plane. The after burner can spend up to 300 liters of fuel per minute in full reheat mode and
give the speed of Mach>2 .Some additional specifications are:-
Thrust of engine full at combat mode 12,500 kg
Max. thrust of engine in dry 7670 kg
LP compressors 4 stage axial flow
LP turbine - Single stage axial flow air cooled NGVs and Turbine blades
HP compressors - 9 stage axial flow with variable 1st
and 2nd
stage stators
HP turbine Single stage axial flow and air cooled NGVs and turbine blades
Max. Air flow 112 Kg/sec.
LPC compression ratio 3.5:1
HPC compression ratio 6.6:1
Total compression ratio 23:1
Max. P2 pressure 37.5 Kg/Cm²
By pass ratio 0.57:1
HPR RPM(N2) - 13,300
LPR RPM(N1) - 10,200
Run down time (HPR) - 25 sec.
Run down time (LPR) 60 sec.

9. Features:-
1. The bypass engines have a bypass ratio of 0.57:1 mass flow of area is increased by
additional bypass air at exit. This increases the propulsive efficiency.
2. IGV of LPC, IGV of HPC & 1st
and 2nd
stage of stator blades of HPC are variable .they
regulate the air flow to LPC & HPC Depending on engine
3. The engine has a C-D nozzle capable of swiveling nozzle{tilting} which enables efficiency
expansion of exhaust gases for improved engine performance & high maneuver ability
4. This engine features a very high thrust to weight ratio of 8:1
5. Max. Deflection of the nozzle is ±14°.
THE SEVERAL PARTS SHORT DETAIL INFORMATION
There are Several Parts of the AL-31FP Engine and several controlling units or aggregates
-
advanced fighter aircraft to give enormous thrust of 6735 kg of each engine, And the
parts of the engines are

10. 1. Nose fairing
It laminar the flow and carry a sensor system for anti-ice system
2. Inlet guide vanes
The purpose of IGV [Inlet Guide Vane] to vary the inlet cross section area of LPCompresser it is
made of titanium alloy & it is a load carrying member of the engine.it has small pours inside
for hot air flow for deicing of engine components.
3. Low pressure compressor
It is purposed to compress the air & supply it to by-pass duct & main duct it consists of 4
stages of stator and rotor assembly LPCR & LPCS
4. Central bevel gearing
Central bevel drive which is said to be heart of power transmission in engine is placed in
intermediate casing
5. High pressure compressor
HPC delivers the highly compressed airs to the main engine duct connected to C.C
(Combustion Chamber) the HPC consist also contain Stator & Rotor blades of 9stages.
6. Combustion chamber
The combustion chamber is the main unit which produce thrust for engine
7. Air to air heat exchanger
Air to air heat exchanger which is a turbine cooling section
8. High pressure turbine
HPT turbine is connected to HPC compressor by means of high pressure spool for producing
shaft power for compressor
9. Low pressure turbine
LPT and LPC are connected by means of low pressure spool similarly it powers LPC with low
pressure spool
10. Turbine support
The bearing support of the turbine section of the load carrying member of the engine. Power
transmitted through it to planes body

11. 11. Mixture & mixture casing
It is intended to mix main duct gas stream with bypass air flow before the transition section
12. Diffuser
in the combustor.
Slower air is also
pressure improves the combustion
13. Afterburner
Afterburner(reheat)
after burning process at the exhaust nozzle to provide thrust
augmentation
15. Tilting unit
The tilting unit consists of fixed and moveable casing the fixed casing is hinged to moveable
casing by means up to pivots
16.Jet nozzle
Jet Nozzle is the C-D nozzle with synchronization drive and control mechanism to control the
nozzle throat
17. Nose Dome
It provides laminar exhaust of air and hot gas for system
18. Bypass duct
By pass air carried through it to cool and partially compressed they last mixed up at mixture
casing with afterburner

12. 1. IGV ASSAMBLY: -
The purpose of IGV [Inlet Guide Vane] to vary the inlet cross section area of LPCompresser it is
made of titanium alloy & it is a load-carrying member of the engine. It consists of 23 internal
and external rings they are connected by themselves with 23 moveable IGVs. The circular ring
cavity on external ring forms a channel to convoy hot air trapped from HPCompressor for the
deicing system. Their leading edge is fixed & trailing edge is moveable capable of deflection
from -30° ~ 0°. In AL31FP, the inlet guide vanes are of variable so that which their local angle of
incidence can be changed according to velocity and altitude of flight automatically by fly by
wire control unit. There is a temperature sensor at this section as this is the intake section in
. If the temperature is very low that there is ice formation it activates anti icing
system, which blows the hot air tapped from turbine section into the hollow section of guide
vanes and heats up the intake air. The guide vanes are manufactured by titanium based alloy
by forging and relevant machine process as per technology. The outer casing is made up of
aluminum alloy by forging and machine process.
2. COMPRESSORS ASSAMBLY: -
Compressors are installed only for providing compressed air to the C.C and other part of the
engine according use. Compressors Are equipped with airfoil shaped blades one fitted with
main spindle known as rotor and other one is fixed with the inner casing in a static condition
which is known as stator one set of rotor and one stage of stator makes a stage the rotor helps
to compress the air and stator helps the compress air to guide into or to make laminar, there
are 3 main assembly of the compressors
1. LPC
2. HPC
3. Compressor of intermediate casing
ALL PARTS DETAILS
Nose Fairing
Guide Vanes

13. LPC (Low Pressure Compressors) -
It is purposed to compress the air & supply it to by-pass duct & main duct it consists of 4
stages of stator and rotor assembly LPCR & LPCS
The LPCR is for the Low Pressure Compressor Rotor it is a cylindrical type
construction & has two supports front roller bearing and rear ball bearing
The LPCS is for Low Pressure Compressor Stator in the casing of stator
blades 1, 2, 3 stages are connected with flanges with helps of special bolts. And has an outer
inner shroud. The outer shrouds are groove in casing.
LPCR
The compressor blades are made up of titanium alloys, which can sustain high pressure due to
their material composition. The raw material of titanium alloy is forged for different size to get
the shape of blades and discs are made from high speed carbide steel according to their stage.
After forging these blades will undergo series of operations like profile making by CNC
machines, broaching, milling, grinding, polishing, coatings are carried out on raw materials in
order to have the desired shape of blades and discs.

14. HPC (High Pressure Compressor)
HPC delivers the highly compressed airs to the main engine duct connected to C.C
(Combustion Chamber) the HPC consist also contain Stator & Rotor blades of 9stages.
HPCR is the High Pressure Compressor rotor It is a drum disk type
construction which consists1st
section which includes 1 3rd
stage of rotor these rotor are
Electron Beam Welded so they cannot be dismantled. The 2nd
stage comprise of these discs of
4, 5, 6 stages of rotor & it has cone type flanges for load bearing
First and second sections are attached to each other By means
of bolts at the specified places of flanges the front trunion is also fixed to this section with
some bolts.
The third section which includes the discs of 7, 8, 9
stages of rotor blades and another disc with labyrinth sealing. These disks are connected to
cone type rear flange section by bolts there are 3 spacer rings installed between casings to
maintain requite clearance. The special bolt passes through this ring, discs & finally attached
to the turbine shaft. It transmit torque from HPTR
HPCS is the high pressure Compressor stator the first casing which
accommodate IGV & first stage of stator blade, 2nd
casing which accommodates fourth to 8th
stage of stator blades the last and 9th
stage stator blade is installed on Combustion Chamber
casing. The HPC blades are also forged blades so they also have to undergo series profile
making operations except first stage remaining stages undergo cold rolling process HPCR

15. Intermediate casing compressor
It is the primary load carrying member of the engine the air delivered from LPC is
divided in bypass main duct flow, thrust from engine is transferred to Aircraft by
this casing It contains of outer ring, inner ring & splitter nose ring, 12 hollow struts
connected, all three rings with each other. The struts are numbered clock wise
view from rear it is a welded construction. to support the HPC casing and LPC
casing and this is used to hang the engine to aircraft. It is made up nickel based
alloy. At intermediate casing there is bypass of LPC compressed air with bypass
ratio of 0.57:1. The bypassed air is used in cooling process by exchanging heat at
combustion chamber through heat exchangers.
Central bevel drive which is said to be heart of power transmission in engine is
also placed in this intermediate casing. Aircraft gear box transmits power to
engine gear box through means of flexible shaft and engine gear box transmits
rotational power to central bevel drive and the bevel gear in this transmits power
to HPC rotor in changing 90 degree of direction of power. So when the HPC rotor
attains 40% of its rpm automatically the aircraft auxiliary power cuts off and
engine turbine power comes into act. While the power is generated by turbine
some amount of power is transmitted to aircraft gear box from central bevel drive
in opposite direction in order to run the aircraft accessories. It is also consisting
Central bevel gear Assembly LPC rotor rear bearing support

16. 3.Combustion Chamber Assembly
The combustion chamber is the main unit of the gas turbine engine where the oxidization
process gets completed and thrust produces for the turbine blades to rotate the shaft
assemble with it. Generally, in combustion chamber the fuel and air mixture get burnt and
produces mechanical energy. This combustion chamber of annular type consists of outer
casing, Inner casing & flame tube. The fuel manifolds supply fuel to the combustion chamber
through 28 duel official burner & Fuel is ignited by two igniter
In AL31FP engine the combustion chamber is annular type combustion
chamber which is having 28 atomizers with two manifolds. It is made of 5 components namely
outer casing, inner casing, flame tube, manifold, burner which are forged separately and
assembled together each other. As the combustion chamber is very hottest section in
chamber, so it is made of Nickel based alloy called BT-20 and the casings are made up
isothermal forging. The forged casings, manifolds, flame-tube, burner, atomizers are sent to
electron discharge machine in order to place holes on them as there is no standard drill bit.
EDM is the efficient process because of drilling of holes takes more time. After combustion
chamber there is an air heat exchanger which is said to be turbine cooling section. It is
activated only when the exhaust temperature of combustion chamber increases by 800
degrees and as well as the rpm of high pressure shaft goes to 92% of its initial rpm. Air heat
exchanger is combination of series of small tubes bent together and braced to each other. One
side there is an inlet of hot gases from combustion chamber and other side there is an outlet
for cooled hot gases to HPT nozzle guide vanes (1 stage turbine stator blades).

17. 4.TURBINE ASSEMBLY: -
In AL31FP the turbine section is a two stage impulse reaction type of turbine. One stage is High
Pressure Turbine (HPT) and the second stage is Low Pressure Turbine (LPT). The turbine discs
and blades are made up of nickel based alloys which are capable of heat resistant. The blades
are specially made by investment casting process with no post surface finishing process
because of its precision.
The HPT turbine is connected to HPC compressor by means of high pressure
spool and LPT and LPC are connected by means of low pressure spool. The low pressure spool
will pass through hollow structure of the low pressure spool. As the hot gases coming from the
combustion chamber initially the gases are guided by the turbine stator blades said to be 1st
stage turbine nozzle guide vanes and passed over through 1st stage turbine rotor blades and
next it passed over the next stage of blades.
HP. Spool
LP. Spool
As the gases at stator blades they are guided and pressurized. The gas molecules expand
through the rotor blades by virtue of kinetic energy of gas molecules transfer to the blades, so
there be an impulse reaction develops over the blades and it causes the turbine to rotate.
There is special cooling unit said to be turbine cooling unit which is activated at high
temperatures which allows to extend the life period turbine section. The HPT rotor blades of is
having a typical aero foil shape with small holes drilled by electron discharge machine so that
these holes are interconnected with disc so that there is cold compressed air flow transfer
between the compressor and turbine through bleed-air system.

18. AL-31FP there are two type of turbine are there
1. LPT- Low Pressure Turbine
2. HPT- High Pressure Turbine
The turbine section incorporates with high pressure and low-pressure single
stage axial turbine, arrange in series and the bearing supports as well. High pressure turbine
rotates high pressure compressors and the units installed in the aircraft accessory gear box
(A.A.G.B) and on engine accessory gear box (E.A.G.B).low pressure turbine rotates the low
pressure compressors and each turbine consists of a rotor and nozzle guide vane (N.G.V )
assembly.
The bearing support of the turbine section of the load-carrying member of the engine. The
radial loads are transmitted from the HP and LP turbine rotors to the bearing supports via the
inter rotor bearing. LP turbine shaft and LP turbine rotor bearing are located in the bearing
support. The turbine section comprises the bearing support casing and bearing casing.
The turbine blades are made of the nickel based alloy metals, those
are high temperature sustainable. Both HPTR and LPTR are single states and having 90 blades.
Turbine Guide Vanes

19. 5.AFTERBURNER&DIFFUSER ASSEMBLY
Afterburner-Afterburner(reheat) used for more cruise improvement and is intended only for
after burning process at the exhaust nozzle to provide
thrust augmentation. Thrust augmentation means to improve the thrust efficiency of engine
which allows better performance in flight mode such as short length take-off and more
cruising speed.
In AL-31FP The Afterburner section consists of 5 fuel manifolds out which primary
manifold supplies fuel to the flame tube and remaining manifolds spray the fuel. At initial
point of afterburner activation, fuel is supplied to primary manifold and oxygen is supplied for
burning initializing process. Then the after burner fuel pump supplies fuel to 2,3,4,5 manifolds
in sequence. Once all the manifolds have fuel there is flame carrier and burning starts at all
manifolds and oxygen supply cuts. There are two flame stabilizers in order to stabilize the
flame one big and the other is small. By activating the afterburner there is increase 6-9% of
actual thrust and there is increase of 15-degree temperature at every 5 sec. & it usages fuels
5 liters/sec mode.
Some afterburner components are-
Exhaust Mixture
It is intended to mix main duct gas stream with bypass airflow before the transition section
Transition Section
It is design to provide for the steady burning of the fuel in the afterburner
Afterburner Casing
It consists of casing & shield some portion of the bypass air is supplied to the space which is
formed by shield and wall or transition section casing and afterburner casing to cool the jet
nozzle and casing.
Exhaust Fairing
It is design to decrease the exhaust gas energy losses
The exhaust fairing preparation is intended to decrease
the afterburner intermediate burning.

20. Diffuser- in the
combustor. Slower air is also
static pressure improves the combustion . There are two casings inner casing and
outer casing made up mnemonic, and compressed air from compressor is passed between
casings in order to cool the hot gases by using bleed air system.
6.TVC nozzle assembly-
The thrust vectoring variable area jet nozzle is an all mode supersonic C-D nozzle their main
parts are
1. Tilting Device
2. Subsonic nozzle
3. Supersonic nozzle
1. The tilting unit consists of fixed and moveable casing the fixed casing is hinged to moveable
casing by means up to pivots. The moveable casing is turned with respect to fixed casing in
maximum angle of ±14° by means of two pairs of hydraulic cylinder located both sides of
horizontal axis of tilting device. The hinged pin of fitting device is turn relative to horizontal
plane in angle 32° counter clockwise for clockwise LH engine and clockwise for RH engine
viewed from rear.

21. 2. Subsonic Jet Nozzle is the convergent nozzle with synchronization drive and control
mechanism to control the nozzle throat are 16 convergent nozzle shutters with 16 sealing
spacers forms the convergent subsonic jet nozzle. The shutters are controlled by 16 hydraulic
cylinders; the hydraulic cylinders are fuel operated to actuate the jack. A high pressure pump
(NP-160D) Delivers fuel under pressure to the jacks. The control is carried out by the engine
nozzle and after burner controller (RSF-31BT1).
3. Supersonic nozzle is a divergent nozzle with synchronization drives and control mechanism
to control the jet nozzle exit area by other shutters. 16 divergent nozzle shutters with 16
sealing spacers forms the divergent supersonic section of jet nozzle. The hydraulic cylinders
control the shutters.
These main parts controlled & fitted with-
1) Jet nozzle casing: It is the outer casing, which is used to connect the
diffuser section and nozzle section. Made up of titanium-based alloy for strain
hardening.
2) Flaps: Flaps are the moving parts in nozzle section that plays a vital role in
controlling the throat area of nozzle. There are different flaps in nozzle section
while viewing in top view with reference to inlet of the engine.
1) Inner flaps/Lower flaps are the flaps before the throat of the nozzle are made
of nickel alloy because of high temperature contact.
2) Upper flaps are the flaps after the throat area.
3) Outer flaps are the flaps covering the inner components of hydraulic,
pneumatic and mechanical linkages and forming nozzle shape
3) Spacers: Spacers are the stationary parts and acts as supporters to the
flaps, which are interconnected with hinge supports. There also different types as
related to the flaps and supports respective flaps. In alignment, one flap and one
spacer are arranged in circular shape and connected with hinge supports.
4) Mechanical linkages: Mechanical linkages are the connecters for different
components of and used in mechanical movements with the activation of
pressure cylinders. Linkages like crossbeam, lever, telescopic support, brackets,
piston rods, limiters.

22. 5) Hydraulic cylinders: 2 types of hydraulic cylinders are used in nozzle
section.
i) One type consists of four cylinders, which is used to tilt the nozzle in
vertical direction up and down 14 degrees with reference of front view.
ii) Second type consists of 16 cylinders, which are used in controlling the
throat area, either expansion/contraction with mechanical linkage to the flaps.
6) Pneumatic cylinders: There are 16 pneumatic cylinders, which is used for
restricting the over, expansion/contraction of nozzle throat area by flaps and it is
limited by limiters around the upper flaps inter connected with cylinders.
7) Graphite ring: Graphite ring is a ring, which is fit in between the nozzle and
diffuser section of afterburner, provides lubrication during the time of tilting, and
covered with jet nozzle casing.

23. AGGREGATES
Aggregates are the most important controlling part of the AL-31FP engine which controls the engine to
provide max performance increase safety level and provide updated information about the engine to the pilot.
The aggregate or (Avionics) part of the engine provides a maximum safety and durability to the engine these
are:-
1> Fuel oil distributer[RT31-VT1]:-
It distributes fuel among first and second stage of fuel manifolds of main combustion chamber.
2> Afterburner fuel pump[RTF-31AT1]:-
It distributes fuel between 1st
, 2nd, 3rd, 4th afterburner manifolds .It also maintains minimum
fuel burns in afterburner section.
3> Booster pump [DTsN-82]:-
It Supplies fuel to main fuel pump[NR-31BT1],Afterburner pump[FN-31AT1] & Plunger
Pump[NP-160D].It usually Increases fuel pressure
pressure fuel system.
4>Emergency Draining Unit [99.10.34.000] OEM:-
It used to drain fuel from aircrafts fuel tank in flight, in emergency landing this feature can be
operated from cockpit directly.

24. 5> Plunger Pump [NP-160D]:-
It supplies fuel to hydraulic cylinders through nozzle & reheat the controller [RSF-31BT1]
6>Fuel oil Filter [8D2.966.133-01]:-
16 micron filters is intended to filter fuel feed to the engine units from foreign particles.
7>Regulator of Nozzle and Afterburner [RSF-31VT1]:-
It consists of 3 parts
a) Jet-Nozzle control System
b) Afterburner Fuel control System
c) Turbine cooling control system.
a) The Jet-Nozzle control system controls throat area for thrust controlling according to the
engine control position.
b) It controls the fuel controls system to afterburner manifolds through afterburner manifolds,
through afterburner fuel distributers [RTF-31FT1]
c) Turbine cooling control system gives hydraulic command for switching on or off turbine
cooling control unit.

25. 8>Regulator-Pump [NR-31VT1]:-
It consists of two major unit part -1>pumping unit [gear type]
-2>Regulator unit
Pumping unit increases fuel pressure supplies from booster pump in relation to HP rotor RPM
[RT-31BT1].Inlet air temp. , Atmospheric pressure. It also controls fuel supply to the low
pressure compressor inlet guide vanes (LPCIGV) & high pressure compressor variable stator
vanes (HPCVSV) in relation to inlet air temp. & HP rotor RPM.
9>Reheating Pump[FN31AT1]:-
Its centrifugal pump intended for increasing the fuel pressure for supply to the afterburner
fuel distributer [RTF-31AT1] through Jet nozzle and afterburner regulator [RSF-31AT1]
10> Gas-capsule type Thermo sensor (TDKM):-
It senses inlet air temp. (t1) & generates hydraulic command to main fuel pump [NR31BT1] &
jet nozzle reheat regulator [RSF31BT1] for correction of fuel flow.
11>Plunger Pump Control unit[AUPN-96BT1]:-It controls the outlet pressure of plunger
pump [NP-160D] for actuation of jet nozzle hydraulic cylinder

26. 12>Aggregate for Setting(p1)of turbine[APP-96BT1]:-
It controls turbine expansion ratio (P2/P4) by changing jet nozzle throat area.
13>Safety Valve(KP-96BT1):-
It bypasses the fuel when plunger pump (NP-160D) pressure increases beyond 240 kg/cm²
14>fuel feed meter [4033 series 69]:-
It is meant for after burner fuel ignition through hot streak method
15>Electro hydraulic distributer[EGR-4VT1]:-
It distributes fuel to hydraulic cylinder for tilting of jet nozzle through. Two independent
electrical channels & one hydraulic channel
16>Fuel oil Heat Exchanger[6139T]:-
It cross flow heat exchanger which cools the heated oil by using outlet fuel from main and
afterburner section

27. 17>Sensor of tachometer[D-3M]:-
This aggregate is intended for supply of electric signal with frequency proportional to that of
LP rotor RPM (n1) & HP rotor RPM (n2) for display at Aircrafts cockpit
18>Synchro Transmitter[DS-11V]:-
These transmitters of 3 numbers are
synchs. This unit measures position of
i>Flaps in jet nozzles
ii>L.P.C.I.G.V
iii>HPCVSV
& it provides signal to MFWS
19>Sensor of lubrication oil Level indicator[DSMK8A-47]:-

28. Oil level sensors mounted over the oil tank to measure the level of engine oil and provides
20> Vibro Speed indicator[MV-27-1G]:-
This aggregate measures the vibration of engine casing. This unit convers the horizontal and
vertical vibration into electrical signal & supply to complex regulation of engines (KRD-99B)
21>Gas turbine engine power unit[GTDE117-1MO]:-
This aggregate is intended to rotate the engine up to Self-sustaining RPM during engine
starting up to cranking RPM (18±30%) during cold / wet cranking & preservation or DE
preservation.
22> Electro Magnetic Valve:-
It is a solvent valve which basically used for Operating Anti ice system. It got feedback from ice
detection units of A/C and automatically opens the airline
23>Complex Regulator of Engine: -

29. It is an electronic control unit. It controls or regulates fuel flow throughout all engine modes. It
receives command from various types of sensor & it controls command for control of Engine
starting, AB mode, turbine cooling, surge etc...
24>Moment sensor: -
These sensors monitor LPCIGV. Flap position. Flap position and HPCVSB position and provide
signals.
25>RPM Sensor: -
I t measures low pressure rotor RPM .It is placed on BKA
26>Heat Resistance Pressure Indicator: -
It is a pressure switch which selects the correct air pressure line to be fed to engine accessory
gear box bearing.
27>Heat Resistance Vibration Stability Pressure indicator: -
It senses pressure in all supply line of turbo stator (GTDE-IA-IMO) and automatically stop the
turbo stator if the oil pressure is less than1kg/Cm²

30. 28.Sensor of transformer pressure: -
The aggregate is a pressure sensor that measures the pressure fuel in the plunger pump
pressure line and transfers this into electrical signal.
29>transformer pressure sensor:-
The aggregate is a transformer type pressures sensor which measures pressure of oil line and
transformers this into electrical signal to feed engine combined controller.

31. Pneumatic Cylinders
Parts Details - This Pneumatic cylinder used in the nozzle of AL-31FP
Flexible inner ring (Courtesy-H.A.L)
Link
(098.7431)NUT Joint
Passage (098.7500)
(104.16.18.004)Piston
Screw
Nut (104.16.18.002)
Lock washer (104.16.003)
Casing (104.10.18.010)
Inside piston
Piston rod (011.16.18.004)
Sealing ring (104.16.18.001)
(104.16.18.005) Locking Plate
(104.16.183.030) Cover
Air Pours
Flexible Link
A study on pneumatic cylinder failure

32. -
Pneumatics is a branch of engineering that deals with the study of makes use of gas or
. Pneumatic systems are commonly powered by compressed air or compressed
inert gases. A centrally located and electrically powered compressor powers cylinders, air
motors, and other pneumatic devices. A pneumatic system controlled through manual or
automatic solenoid valves is selected when it provides a light weight, lower cost, more flexible,
or safer alternative to electric motors, actuators & hydraulic oil storage.
Pneumatic cylinder or (air
cylinder) is the component or mechanical device which converts the fluid energy or
pressurized air force to mechanical energy or linear Compressed air
forces a piston to move in the desired direction. The piston is a cylinder, and the piston rod
transfers the force it develops to the object to be moved. Once actuated, compressed air
enters into the tube at one end of the piston and, hence, imparts force on the piston.
Consequently, the piston becomes displaced. Materials can be nickel-plated brass to
aluminum, and even steel and stainless-steel. Depending on the level of loads, humidity,
.
Types and design-
TYPES
1 Single acting
2 Double acting
3 Telescopic, Multi stage
4 Through rod air cylinders
5 Cushion end air cylinders
6 Rotary air cylinders
7 Rod less air cylinders
8 Tandem air cylinder
9 Impact air cylinder
DESIGN
Depending on the job specification, there are multiple forms of body constructions available
1 Tie rod cylinders: The most common cylinder constructions that can be used in many types
of loads. Has been proven to be the safest form.
2 Flanged-type cylinders: Fixed flanges are added to the ends of cylinder; however, this form
of construction is more common in hydraulic cylinder construction

33. 3 One-piece welded cylinders: Ends are welded or crimped to the tube, this form is
inexpensive but makes the cylinder non-serviceable
4 Threaded end cylinders: Ends are screwed onto the tube body. The reduction of material can
weaken the tube and may introduce thread concentricity problems to the system.
Working principles, area, force relationship-
1. Rod stresses
Due to the forces acting on the cylinder, the piston rod is the most stressed component and
has to be designed to withstand high amounts of bending, tensile and compressive forces.
Depending on how long the piston rod is, stresses can be calculated differently. If the rods
length is less than 10 times the diameter, then it may be treated as a rigid body which has
compressive or tensile forces acting on it. In which case the relationship is:
F =
Where:
F is the compressive or tensile force
A is the cross-sectional area of the piston rod
is the stress
2. Instroke and outstroke
Although the diameter of the piston and the force exerted by a cylinder are related, they are
not directly proportional to one another. Additionally, the typical mathematical relationship
between the two assumes that the air supply does not become saturated. Due to the effective
cross sectional area reduced by the area of the piston rod, the instroke force is less than the
outstroke force when both are powered pneumatically and by same supply of compressed gas.
The relationship between the force, radius, and pressure can derived from simple distributed
load equation

34. Fr = PAe
Where:
Fr is the resultant force
P is the pressure or distributed load on the surface
Ae is the effective cross sectional area the load is acting on
Outstroke
Using the distributed load equation provided the Ae can be replaced with area of the piston
surface where the pressure is acting on.
Fr = P( 2)
Where:
Fr represents the resultant force
r represents the radius of the piston
is pi, approximately equal to 3.14159
Instroke
On instroke, the same relationship between force exerted, pressure and effective cross
sectional area applies as discussed above for outstroke. However, since the cross sectional
area is less than the piston area the relationship between force, pressure and radius is
different. The calculation isn't more complicated though, since the effective cross sectional
area is merely that of the piston surface minus the cross sectional area of the piston rod.
For instroke, therefore, the relationship between force exerted, pressure, radius of the piston,
and radius of the piston rod, is as follows:

35. Where:
Fr represents the resultant force
r1 represents the radius of the piston
r2 represents the radius of the piston rod
is pi, approximately equal to 3.14159
The pneumatic cylinder in Spacers are also similarly operated it is a single acting cylinder
which the acting piston and the outlet passage are in one side the air pour in the plate helps
for the reciprocating motion of the piston and used to close the spacers.
Using purpose
Simplicity of design and control Machines are easily designed using standard cylinders
and other components, and operate via simple on-off control.
Reliability Pneumatic systems generally have long operating lives and require little
maintenance. Because gas is compressible, equipment is less subject to shock damage.
Gas absorbs excessive force, whereas fluid in hydraulics directly transfers force.
Compressed gas can be stored, so machines still run for a while if electrical power is lost.
Safety there is a very low chance of fire compared to hydraulic oil. Newer machines
are usually overloading safe.
Light weight- Pneumatic cylinders are light weight and does not required large amount of
storage for hydraulic fluid.
Main failure reasons and controlling them-
Pressure loss is the main failure reason of the pneumatic cylinder of the V.J.N in the AL-31FP
engine. the cylinder should sustain 5k.g of air pressure constantly and in pressure testing
machine it should be 95 bar of pressure. But if the cylinder unable to maintain 5k.g of pressure
constantly then it will be rejected and again many manufacturing process and special process
will be done to make a new cylinder.
There are two types of pressure loss testing carried out first is the
newly manufactured cylinders for new engines and second one is of the overhaul engines

36. cylinders, the overhaul engines cylinders are basically failed because of coating wear out but in
the new cylinder they failed for pressure loss.
There are so many factors that affect the cylinder among one of
them is the leak. The leak is the greatest factor that can lead up to pressure loss and also stop
the cylinder to work. The cylinder at the time of testing also have a leak test to ensure that it
does not have any internal damage which can lead up to leak.
Pressure-loss test & leak test
Pressure-loss-
Pressure-loss Carrie out by the apparatus in which a square type metallic box has a tube for air
injecting and designed for inside air vacuuming the cylinder set by semi opened and fixed in that box.
After cylinder fixed inside that box it closed and vacuumed then 5k.g of air pressure injected through
the tube with mass flow rate of2.0839 to the link continuously if the pressure drops in the middle of
the operation without sustaining 5kg/95 bar pressure then it is rejected.
Leak test-
This test carried out with white kerosene/turbonic oil under a cotton napkin with a pressure force of
35 36 Kgf/cm² (35×10 A) for 10 11 minutes
Preventing the loss in pressure and leak can control the 80% of the rejection of pneumatic
cylinder in whole production in HAL (Koraputdivision), but before we must know about the
function of the cylinder briefly.
Below this is a schematic cross-
sectional diagram & modeled diagram of the pneumatic cylinder which is single acting and it
placed in the flaps of VJN in a ringed shape (16 s) for closing them.
Modeled figure of
actual cylinder
Courtesy HAL & Russian patents

37. Detailed work (Courtesy HAL & Russian patents)
Pneumatic cylinder drive jet nozzle of a gas turbine engine includes a housing 1- with a cover 2- a
piston 3- the casing 4. In the housing it has a hole. 5-for supplying air into the rod cavity 6- the holes 7-
connecting the cavity-8 that is made from the opposite end of the body. The output- 10 of the cavity
cooling-9 may be made in the form of holes of different sizes in the sector of 180 degrees from a line
12 connecting the axis of the jet nozzle with the axis-13 of the cylinder. In the piston-3 with the sealing
ring-14 in contacts with the working surface of the housing-1.
When the cylinder air is supplied into the rod cavity-6 of the pneumatic cylinder. The air passing
through the sealing ring 14 of the piston 3, the through holes 7 is fed into the cavity cooling 9. Air
passing through the cavity cooling 9, cools the body 1 and is ejected through the openings 12 to the
outside. The most cooled is the most heated part of the housing 1, rotated to the axis of the jet nozzle. It
is a better cooling of the housing reduces the temperature differential housing in the circumferential
direction. This ensures the most cylindricity and straightness of the housing of the pneumatic cylinder.
Simply the
single acting pneumatic cylinder works normally as others and the internal chromium layer coating acts
as a lubricant & keep safe from vapor contaminants and rings gives it a smooth operation.
Normal failure reasons of the pneumatic cylinder-
Contaminants
Cylinders can be contaminated internally from the air supply or externally from the
operating environment. Types of contamination include solids, water and oil. As an
example of the potential adverse effects of contamination, solids such as particulates,
pipe rust and scale and thread sealant debris can curtail seal life, plug orifices and
damage surface finishes.
Solids: Gritty environments can wreak havoc with pneumatic cylinder systems. Once
any type of particulate penetrates a nose seal, it can embed itself in seals and
bearings, turning them into virtual sandpaper. But the potential damage resulting from
intact and in place until the system is actually fitted with piping. A second option is to
thoroughly clean piping before connecting it to cylinder ports to remove chips, burrs
and debris left over from threading and flaring operations.
When cylinders function in hostile operating environments where excessive heat,
chemicals, paint or weld splatter are present, shields can be installed to prevent piston
rod and rod-seal damage. Additional installation options include using a metallic wiper
to remove larger particulates from the rod or adding a rod boot to ensure further
protection. Improving air filtration is another option to enhance cylinder performance.
Water: Water vapor is present in all compressed air applications, where it collects
within components to block orifice flow through, dilute pre-lubrication grease,
adulterate airline lubricants, damage barrel or rod finish and freeze in cold weather.

38. Installation options to reduce the deleterious effects of water vapor include using
coatings of layers inside of cylinder
Oils: Another type of pneumatic cylinder contaminant consists of oils resulting from air
compressor lubrication carryover or synthetic oils that are typically incompatible with
air-line components. Such oils can cause seal swelling and orifice plugging. Again,
plant engineers have the option of selecting seals that are compatible with oils used in
the application to dramatically reduce the damaging effects of such contaminants.
Insufficient lubrication
Catastrophic failure can also occur when cylinder seals have insufficient lubrication.
High or fast cycle rates can generate unsustainable shock loads at the end of a stroke
when the piston hits the end-cap, or seals can simply run dry from a lack of lubrication.
Heat generated by the system could compromise component temperature limits.
Whatever the reason for cylinder malfunction, steps can be taken to anticipate and
prevent failure.
Operating over component limits
Operating a cylinder over pressure, load and/or energy limits can also cause the
higher stress and friction rates. Rod ends bend or break, and actuators can come
apart. If the system contains speed control or energy-absorbing devices, pressure
spikes can also occur that are two to three times above normal system pressures
Actual defects found on AL-31FP Pneumatic Cylinder and their results-
Investigating on the Detail working procedure of the cylinders first basic thing which comes out that the most imported
item like cylinders and others which directly imported from Russia shows various defects, Therefore the machining and
other manufacturing process which now operated in Hal (Koraput div.) shows less defects as well as good quality hence
the materials still imported from Russia as billet shape.
The New & old (over-haul) both cylinders having the same issue with the shape when their inner coating
(CROMIUM COATING FOR ANTI OXIDIZATION AND SMOOTHNESS) grinding process the thin shape of the cylinder
becomes little oval shape with the incorrect grinding procedure and the sealing ring also failed for this reason for which
the air sustaining capacity of 5 kg becomes less,
And another reason due to the Piston manufacturing, the piston without coating and with improper
manufacturing cause the pressure leak which also a reason. The special coating (Graphite or similar) provides it a
lubricated surface as similar as leak-proof.
The third one and the most important are the piston rings those provide the
cylinder to work properly makes more friction-less and smooth with leak-proof surface. These rings wear out also can
cause a serious damage to the surface of the chromium coating decrease its life span as frequently as its pressure
sustaining ability of 5kg. Thus these 100% probable problems were found during our study of the Pneumatic cylinder of
the VJN assembly we collect this information from the respective workers and managers of the shop after taking
precaution about this the 40% more improvements in the manufacturing has been achieved.

39. SU-30MKI-SIDE WINDER