Jhunjhun Report Matter

7/28/2019 Jhunjhun Report Matter

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ABSTRACT

The main aim behind this project is to design a test facility for the effective performance

of the Auxiliary Power Unit. This test bed is to be designed keeping in mind the parameters and

norms of effective quality assurance and reusability with zero maintenance. The test bed is to be

designed in such a way that it is user friendly when it comes to engine handling. The test rig has

to go through a stress analysis process in order to ensure that the structure is not affected and can

withstand prolonged engine usage for endurance testing purposes. This report contains the detail

analysis of the systems used in test facility and the problems faced during the designing of the

test bed in a design facility.


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INDEX

INTRODUCTION OBJECTIVE OF THE STUDY METHODOLOGY OF THE STUDY STATEMENT OF THE PROBLEM FINAL RESULT

CONCLUSION

SCOPE OF FUTURE STUDY BIODATA BIBLOGPAHY AND REFERENCES


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1. INTRODUCTION

Description of Test Component for Testing:

Auxiliary Power unit (APU):- The main purpose of an aircraft APU is to normally fulfil

several functions of the aircraft namely:

Main engine starting. Supply of cooling air for aircraft secondary systems, particularly when at ground idle

in hot climates.

Supply of electrical power when main engines are shut down, including for groundcheckout of aircraft systems.

These functions give an aircraft a self sufficiency when on the ground. In addition an

APU will be required to fire up at altitude in case of main engine flame out, to power

electrical systemsvital for fly by wire aircraftsand if at low flight mach nos. to

provide crank assistance to help restart the engines.

For civil applications APU requirements may include operations in all regions of flight

envelope, and for military aircrafts advanced systems with start times as low as a second.

A current typical start time is around 6 seconds at 15000 meters.


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The main requirements for the APUs have been

Low development and unit costs High reliability and maintainability. Low volume and weight Good specific fuel consumption.

APUs for aircrafts are generally exclusively simple cycle gas turbines. Fuel consumption of

APU is the secondary issue where operation is intermittent. Generally the output power range of

the APU is between 10 kW and 300kW.

The advantages of having an APU in an aircraft can be

Main engine starting. Supply of cooling air for aircraft secondary systems, particularly when at ground, idle in

hot climates.

Supply of electrical power when main engines are shut down, including for groundcheckout of aircraft systems.


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2. OBJECTIVE OF THE PROJECT

Personal objective:

To obtain practical knowledge on test facilities of APU and successfully complete the final year

project.

The objective of the project is:

1. To design a test facility for mounting and testing of an Auxiliary Power Unit.2. To understand the main functions of an APU.3. To measure the parameters regarding the operation of APU4. To analyse the primary and secondary systems needed in the test bed for working on the

APU engine.

5. To provide a detuner design for reducing acoustic levels of the noise produced by theexhaust gases of the detuner while working.

6. To study about the engine handling procedure.


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3. METHODOLOGY OF DESIGN

The auxiliary power unit is an optimum weighted engine. The engine weighs approximately 65

Kg which is optimum for being the weight of an APU of a medium scale aircraft. The APU is to

be mounted on a test frame where the various performance tests.

The test frame that is to be designed should meet the following criteria:

The connections from the frame to the engine mounting points should be calculatedperfectly so that there is zero clearance.

It should be stable (should not wobble while engine operation). It should be of an optimum height for easy handling and rigging of the APU. It should provide ample room for the engineer to easily mount the engine and join the

necessary connections and wires (fuel, electrical and control systems ).

It should not be made with less but robust material. The sectional joints should be able to withstand normal vibrations and forces due to

moment caused by the APU functioning.

It should meet all the safety standards and should be safe for operation.The test frame that is to be designed is manufactured of mild steel material. The material ensures

extra structural stability and robustness to the test frame design. Additional care is given for the

test frame to be resistant to engine vibrations and moment. The test frame is made of hollow

beams of 4mm thickness as per the design parameters and structural analysis. Below we are

about to discuss the steps that were performed while designing the test frame and the reasons for

selecting that particular design. The design that is done using a design software, in this case that

is Autodesk Inventor professional 2012. This is the latest software released by Autodesk


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company which has got many new features apart from the traditional features that has already

been there since the first version of the software release. The constraining features of the

software made it easier to choose for the project.

Step 1: Study of existing designs.Step 1 includes creating a sketch for reference while using the design software. A

thorough study of some existing designs of test beds was done before creating a free hand

sketch of the design. Subsequently it was constructed on scaled parameters.

A little modification was done to the existing designs and the new model was sketched.

Step 2: Sketching using Inventor software.Individual parts of the test frame were required to be sketched separately and then

extruded as per the requirements and the design specifications. Parts that were designed

using the software are discussed below:


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1) Ground plate

The ground plate is that section of the test bed that is bolted to the ground foundation.

The slots are designed as per the requirement of the test bed. The length of the base

plate is 1775mm and width is 220mm. The slot that is made is of radius 10mm and

length 40mm.


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3) Base frame:

As mentioned before , the base frame is a very important part of the test frame. Basically

it is the place where the pillars and the mounting frame along with the base plate on

which the mounting frame rests , are assembled. The base frame is of 2880mm X

1490mm dimension and of 75mm thickness. The slots on which the mounting frame is

to be placed is designed at 1081mm distance from and 398mm distance from each other.

This helps the mounting frame to rest on the base plate.


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4) Base plate (mounting frame mate):

The base plate is the mate of the mounting frame and the base frame. Both the structures are

assembled and joined at the constrained part of the assembly.

The base plate has four holes with threads of standard m12 bolts. The base plate is to be welded

with the mounting frame so that it joins to the base of the mounting frame. After that the base

plate is required to be bolted to the base frame so that the mounting frame rests on the base

frame. Standard m12 bolts are available for usage in the industries. One of the nuts drawing is

given below.


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An altogether of 16 nuts and bolts is used to fix the mounting frame with the base frame.

5) Mounting frame:a. Mounting frame 1 :


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The frame that is shown above is the initial prototype of the test frame on which the

engine is to be mounted. The design is robust as it has got a truss structure in it and is

stiffened by an slanting support at an angle 20 degrees at its back. The slant stiffener

is responsible for balancing the counter force produced by the APU while

functioning. The slant section but creates a problem for engine handling . in addition

the cross section on the frame increases problem in engine handling and rigging

process. The design also demands the usage of extra material (MS).

The height of the side mounting point is located at 800mm from the base of the frame

and the height of the top edge is 1100mm from the base. The distance of the base

stands is 400mmX400mm from each other.

Advantage of this design:

1. The frame is very stable and will be subjected to know bending moment orstructural failure due to engine operation.

Disadvantage of this design:

1.The design will use more material.2.The design may wobble due to vibrations caused by the APU.Hence it was required to review the design and re-create a design that meets all these

needs and leaves no disadvantages.


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b. Mounting frame 2:

The reviewed mounting frame has the same outer structure as the previous prototype.

However in this frame the structure is a little modified. The truss or the X shaped

stiffeners have been lowered in height to prevent the frame from wobbling. The

presence of the truss at the lower end ensures that the frame is stable but at the same

time ensures that there is no problem in engine handling.

The stiffeners are at a height of 360mm from base and apart from that there are no

additional changes as such.


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c. Mounting frame 3:

After reviews and modifications, a third mounting frame was designed keeping in mind all the

problems and corrections made. The new mounting frame becomes efficient in engine handing as

there is no obstruction between the engineer and the engine while rigging the engine. At the

same time the engine was to be mounted on a rigid and stable frame. In return to that, this design

gave the structure a stability and shape that is best augmented towards its use for the testing of

the APU.


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6) Assembly 1 : Includes the base plate , pillars and the base frame :

The base frame is comprised of ground plate, pillars & base frame. The ground plate is bolted

into the ground via slot provided At the edges. The pillars are welded onto the ground plate. The

pillars are placed at a distance of 80mm from the front & back. The side clearance is 10mm for

pillars from the ground plate. The base frame is welded onto the pillars.The entire base frame

rests on 4 sets of pillars & ground plates, calculated in such a way that proper clearance for

bolting of frame onto the base frame is ensured.

The base frame assembly forms the main supporting structure for the test frame design.The base

frame structure provides the necessary groun support for the entire test facility.


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Assembly 2 without engine:

Proposed design 1:

This frame assembly was 1st

achieved with the help of precise calculations & merging of frame

base plates with the markings onto the base frame. The frame base plates are welded onto the

frame legs. The bolting is done using M12 bolts & nuts. Bolting provides the necessary rigidity

to the test frame structure. The frame structure above was designed with stiffeners at 1/3rd

height

from the frame base & at the side to provide extra thickness.


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However it was realise that it was not require & also that it could prove as an obstacle during

engine handling which is not desired.The frame structure has mounting plates fixed to it as per

the dimensions of the mounting points onto the engine which are predetermined. The main aim

of the test frame design is to accurately calculate the mounting plate location w.r.t. the engine

mounting points in order to ease the mounting in such a way that the engine is statically stable

during mounting & testing.

The frame is designed in such a way that the engine axis is at the height of 1375mm (550mm

base frame assembly + 825mm mounting point at the axis), ie.4.51 feet from the ground level.

This provides ease in engine handling during testing. There is also 4 stiffeners from the sides of

the mounting frame so that the stability is maintained and uniform.

Advantages:

1. It has more structural stability than the first design and also gives a lot ofclearance for engine handling.

Disadvantages :

1. It has got a little space in the bottom for the engine rigging and de-riggingprocess.

2. The design uses more material in this case mild steel which is not economical.


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b. proposed design 2:

The test frame structure above was the modified version of the frame. It has the same dimensions

of the earlier mentioned base frame & frame bolting assembly as the above. However, the engine

specifications did not require extra stiffeners at 1/3rd

height. So the stiffeners at the centre were

removed & only the stiffeners onto the side were kept.

This design will ensure ease in engine handling which is desirable during rigging & de-rigging

process of engine testing. The test bed with the engine from different projections:-


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The above design shows the engine mounting onto the desired frame.

It can be visible clearly the ease with which the engine mounting & handling can be carried out

with the above frame design.


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The above diagram shows the rejected design of the test-frame.

The central stiffeners added to the load and could also possibly hinder the engine

handling process.


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METHOD FOR HANDLING A GAS TURBINE ENGINE DURING

PACKAGING

The method given here is used for handing a gas turbine engine during packaging. The method

comprises receiving the engine at a handling apparatus pivotally secured to the floor, removably

connecting the engine to the handling apparatus, pivoting the engine while supported on the

handling apparatus, lowering the engine into a container, and then removably connecting the

engine to the container.

BACKGROUND

Oftentimes, small gas turbine engines are individually put in containers at a manufacturing or

maintenance plant before being shipped elsewhere or stored. The gas turbine engines are moved

within the plant on engine transport devices. They are then transferred to a fixed structure

sometimes referred to as a shipping post. The shipping post holds the engine while one or

more technicians perform some tasks on the engine. This procedure, however, often require

numerous transfers from the shipping post to other supporting devices in order for the various

packaging tasks to be accomplished. These transfers are time-consuming and accordingly, often

result in a loss of productivity. Room for improvements exists.


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CLAIMS

1. A method for handling a gas turbine engine during packaging, the method comprising:

A. Receiving the engine at a handling apparatus having a post pivotally secured to the floor for

rotation about a generally vertical axis fixed with respect to the ground;

B. Rigidly connecting the engine to a support fixed to the post in rotation along, the vertical axis

of the handling apparatus, away from a container;

C. Pivoting the engine while supported on the handling apparatus by pivoting the post of the

handling apparatus about the vertical axis fixed with respect to the ground until the engine is in

vertical register with the container;

D. Lowering the engine into the container by translating the support in the handling apparatus;

and then removably connecting the engine to the container.

2. The method as defined in claim A, further comprising: disconnecting the engine from an

engine transport device after removably connecting the engine to the handling apparatus.

3. The method as defined in claim A, further comprising raising at least once the engine with

reference to the floor using the support of the handling apparatus.

4. The method as defined in claim A, further comprising: disconnecting the engine from the

handling apparatus after having removably connected the engine to the container.


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5. A method for handling a gas turbine engine prior from being set in a container, the method

comprising: rigidly connecting the engine to a support of a handling apparatus, the apparatus

having a post upon which the support is fixed in rotation along a vertical axis, the post being

rotatable around the substantially vertical axis fixed with respect to the ground, away from the

container, disconnecting the engine from a structure holding the engine immediately before the

handling apparatus; rotating the engine around the vertical axis of the apparatus fixed with

respect to the ground until the engine is in vertical register with the container; and then lowering

the engine into the container by translating the support along the handling apparatus.

6. The method as defined in claim 5, wherein the structure includes an engine transport system.

7. The method as defined in claim 5, wherein disconnecting the engine from the apparatus

includes removing the support from the engine.

8. The method as defined in claim 5, further comprising: raising at least once the engine with

reference to the floor using the handling apparatus.

9. The method as defined in claim 5, further comprising: removably connecting the engine to the

container.

10. A method of packaging a gas turbine engine into a container, the method comprising:

Receiving the engine at a handling apparatus having a post pivotally secured to the floorfor rotation about a generally vertical axis fixed with respect to the ground.

Rigidly connecting the engine to a support of the handling apparatus, away from thecontainer, the support being fixed to the post in rotation along the vertical axis.


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Performing at least one packaging task on the engine and raising the engine at least onceby translation of the support while the engine is continuously supported by the handling

apparatus.

Pivoting the engine while supported on the handling apparatus by pivoting the handlingapparatus about the vertical axis fixed with respect to the ground until the engine is in

vertical register with the container; and then transferring the engine directly into the

container.

11. The method as defined in claim 10, wherein transferring the engine into the container

includes removably connecting the engine to the container.

It should be noted that the word packaging is a generic word designating the various tasks

required to put an engine in a container, and may include the transfer of the engine from an

engine transport device to the handling apparatus. These tasks can include, for example, draining

fluids used in the engine during a bench test, installing plugs to cover openings, securing wires

together, etc. A wide range of other tasks can be done as well. Once in the container, the engine

can be, for instance, shipped elsewhere or stored while in the container. The engine in the

container can be a fully-assembled engine or an engine in which some parts will be assembled

later. Also, the word handling is a generic word designating the various steps of moving the

engine during packaging.

The apparatus has a base secured to the floor or to a similar solid structure. The base can be in

the form of a plate bolted to the floor. It holds a turntable having a substantially vertical pivot

axis. The turntable has one end secured to the base and other end that is attached to the bottom


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end of a substantially vertical post by means of a sleeve. The post is rotatable around the vertical

pivot axis. The apparatus also comprises a substantially horizontal side arm projecting from the

post. In the illustrated embodiment, the side arm projects from the upper end of the post. The

connection between the post and the side arm can be made in a number of ways. In the illustrated

example, the connection includes a sleeve rigidly attached over the upper end of the post. The

side arm is welded or otherwise attached to the sleeve.

A hoist is provided on the side arm. The hoist can include, for instance, a pneumatic motor

mechanically connected to a reel supporting a chain or a sling.

Gas turbine engines often have two opposite integrated side plates by which the engine can be

connected to another structure. The handling apparatus comprises a rigid side support having one

end in sliding engagement with the post and an opposite end that can be removably connected to

one of the side plates of the engine through an engine mount. The support is said to be rigid,

which means that the support is normally rigidly holding the engine in the same position. This

facilitates the tasks of the technician or technicians. This does not exclude the possibility of

having an adjustable support in which the orientation of the engine can be changed in accordance

with one or more degrees of freedom. The connection of the side support with the post can

include a flange or another element that is operatively connected to the post . In the illustrated

example, the flange of the side support is slid ably connected to a vertically-extending slot (not

shown) on the side of the post. The slot, the side arm and the support are in registry with each

other. The support is held by the sling of the hoist , which sling has a free end attached to a hook

or a hole provided on the support .


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If desired, the post can be provided with a plurality of spaced-apart horizontal holes crossing the

vertically-extending slot on the post . One or more pins can then be inserted below the

support to prevent the engine when one is connected to the support , from falling towards the

floor in case of a failure of the hoist or any of the parts to which it is connected.

A brake can be used next to the base to prevent the turntable , and thus all the other elements

connected thereto, from rotating when that is not required. In the illustrated example, the

brake includes an actuator with a piston having an end engaging the bottom side of a disk on the

pivotal side of the turntable. The actuator of the brake can be electric, pneumatic, hydraulic, etc.

The above description is meant to be exemplary only, and one skilled in the art will recognize

that changes can be made to what is described above without departing from the scope of the

appended claims. For example, the hoist can be manually powered or powered using an electric

or hydraulic motor. The hoist motor, if any, and its reel do not necessarily need to be provided on

a side arm. It can be provided on the post itself, for instance, and the sling or chain can then

reach the proper location on the side arm using one or more pulleys. Alternatively, the hoist can

be in the form of a screw inside the post and engaged to a follower designed to move the support

up or down. A side arm can then be omitted. The slot along the post and which receives the edge

of the support can be replaced by an equivalent system, such as a slot in the support and which

engages a vertical flange projecting on the side of the post, a carriage with rolls engaged around

the post, etc. The brake at the bottom of the apparatus can include pins or similar fasteners to be

inserted in corresponding holes so as to prevent the apparatus from rotating. Although it has been

suggested in the detailed description that the engine be connected inside the container before

disconnecting it from the support of the apparatus, thereby maintaining a constant attachment


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with a rigid structure at all time, it is possible to design the container so as to temporally support

the engine while it is disconnected from the support and prior to connecting it to the container.

Although the post is said to be vertical or substantially vertical, it can define a certain angle with

the vertical. Similarly, a side arm connected to the post must not necessarily be horizontal and

can define a certain angle with the horizontal. It is possible to have a portion of the support of the

apparatus being detachable from the rest of the apparatus. This way, the detachable portion can

remain with the engine in the container. The engine transport device may be different. Still other

modifications will be apparent to those skilled in the art, in light of a review of this disclosure,

and such modifications are intended to fall within the appended claims


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STATEMENT OF THE PROBLEMS

PROBLEMS THAT MAY BE ENCOUNTERED WHILE THE PROJECTWORK

The accepted design may fail the stress analysis test. Designing of the test bed has to be calculated according to the changing requirements. The values of the parameters may go beyond the tolerance limits due to faulty feedback

from the systems.

Problems encountered during the actual assembly process of the test facility. Detuner designing may be complicated due to noise levels and acoustic problems. Detuner designing may be complicated due to space available in the test bed. For the designing of detuner the selection of proper material so that it does not fail the

endurance parameters.

Detuner design may be complicated due to parameters of back pressure and hightemperature.

.


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FINAL RESULT

Post studying and analysing the project, it is concluded that all the designs and

modifications are as per the needed operational specifications for the auxiliary power unit. A

well planned and developed test facility is necessary for successful operation and working over

the APU engine.

The performance and testing of the auxiliary power unit depends upon the following factors

during operation:-

Mass Flow Rate of air Mass flow rate of fuel Exhaust Exhaust gas temperature Test bed structural stability Acoustic levels Control system


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Power output Performance rating Systems used while working Handling check and pass off settings Ease of operating

CONCLUSION

It will also help in planning and implementing of the layout of the test bed.

The layout will help in placing and adjusting the systems over the engine according to the space

available in the test bed room.

A qualitatively and quantitatively good test bed facility is necessary for the efficient and desired

working of the APUMain Gas Turbine Engine.

Building of an effective test facility which can be further used for testing of any APU Main

Gas Turbine Engine.

The test facility is well equipped to carry out all the performance tests to examine the

performance parameters expected from the APU.

The test bed should have various systems for the healthy working over the APU engine.

The proposed test bed facility is designed in such a way that it can be used in different extreme

weather conditions. As well the mounting assembly is made in such a manner that the APU

engine of any aircraft can be easily mounted on the frame.


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The control systems are well equipped so that the testing can be carried out smoothly and totally

controlled.

The designed detuners will reduce to noise levels considerably and substantially along with the

exit velocity and exit temperature of the exhaust gases.

BIBLOGRAPHY & REFERENCES

GAS TURBINE ENGINEWALSH AND FLECTHER AIRCRAFT PERFORMANCEJr. J D ANDERSON GAS TURBINECOHEN AND ROGERS WIKIPEDIA INTERNET SOURCE GOOGLE - SEARCH ENGINE AGARD SPECIFICATION OF TEST BED TRAINING NOTES FOR TEST BED - HAL

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