CAE Oxford Aviation Academy. ATPL Book 4 Powerplant

460 Pages·64.588 MB·English

POWERPLANT
ATPL GROUND TRAINING SERIES
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Introduction
© CAE Oxford Aviation Academy (UK) Limited 2014
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All Rights Reserved
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uc This text book is to be used only for the purpose of private study by individuals and may not be reproduced in
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io any form or medium, copied, stored in a retrieval system, lent, hired, rented, transmitted or adapted in whole or
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in part without the prior written consent of CAE Oxford Aviation Academy.
Copyright in all documents and materials bound within these covers or attached hereto, excluding that material
which is reproduced by the kind permission of third parties and acknowledged as such, belongs exclusively to CAE
Oxford Aviation Academy.
Certain copyright material is reproduced with the permission of the International Civil Aviation Organisation, the
United Kingdom Civil Aviation Authority and the European Aviation Safety Agency (EASA).
This text book has been written and published as a reference work to assist students enrolled on an approved
EASA Air Transport Pilot Licence (ATPL) course to prepare themselves for the EASA ATPL theoretical knowledge
examinations. Nothing in the content of this book is to be interpreted as constituting instruction or advice
relating to practical flying.
Whilst every effort has been made to ensure the accuracy of the information contained within this book, neither
CAE Oxford Aviation Academy nor the distributor gives any warranty as to its accuracy or otherwise. Students
preparing for the EASA ATPL (A) theoretical knowledge examinations should not regard this book as a substitute
for the EASA ATPL (A) theoretical knowledge training syllabus published in the current edition of ‘Part-FCL 1’ (the
Syllabus). The Syllabus constitutes the sole authoritative definition of the subject matter to be studied in an EASA
ATPL (A) theoretical knowledge training programme. No student should prepare for, or is currently entitled to enter
himself/herself for the EASA ATPL (A) theoretical knowledge examinations without first being enrolled in a training
school which has been granted approval by an EASA authorised national aviation authority to deliver EASA ATPL
(A) training.
CAE Oxford Aviation Academy excludes all liability for any loss or damage incurred or suffered as a result of any
reliance on all or part of this book except for any liability for death or personal injury resulting from CAE Oxford
Aviation Academy’s negligence or any other liability which may not legally be excluded.
Printed in Singapore by KHL Printing Co. Pte Ltd
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Textbook Series
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Book Title Subject d
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1 010 Air Law I
2 020 Aircraft General Knowledge 1 Airframes & Systems
Fuselage, Wings & Stabilising Surfaces
Landing Gear
FHlyigdhrta uCloicnstrols
Air Systems & Air Conditioning
Anti-icing & De-icing
Fuel Systems
Emergency Equipment
3 020 Aircraft General Knowledge 2 Electrics – Electronics
Direct Current
Alternating Current
4 020 Aircraft General Knowledge 3 Powerplant
Piston Engines
Gas Turbines
5 020 Aircraft General Knowledge 4 Instrumentation
Flight Instruments
Warning & Recording
Automatic Flight Control
Power Plant & System Monitoring Instruments
6 030 Flight Performance & Planning 1 Mass & Balance
Performance
7 030 Flight Performance & Planning 2 Flight Planning & Monitoring
8 040 Human Performance & Limitations
9 050 Meteorology
10 060 Navigation 1 General Navigation
11 060 Navigation 2 Radio Navigation
12 070 Operational Procedures
13 080 Principles of Flight
14 090 Communications VFR Communications
IFR Communications
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Contents
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Piston Engines
1. Piston Engines - Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
23.. PPiissttoonn EEnnggiinneess -- GLuebnreicraatl i.o n. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ..1411
4. Piston Engines - Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55
5. Piston Engines - Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
6. Piston Engines - Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75
7. Piston Engines - Mixture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .91
8. Piston Engines - Carburettors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101
9. Piston Engines - Icing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
10. Piston Engines - Fuel Injection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .123
11. Piston Engines - Performance and Power Augmentation . . . . . . . . . . . . . . . . . . .133
12. Piston Engines - Propellers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .161
Gas Turbines
13. Gas Turbines - Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
14. Gas Turbines - Air Inlets. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217
15. Gas Turbines - Compressors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
16. Gas Turbines - Combustion Chambers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245
17. Gas Turbines - The Turbine Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .263
18. Gas Turbines - The Exhaust System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
19. Gas Turbines - Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .291
20. Gas Turbines - Thrust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .307
21. Gas Turbines - Reverse Thrust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .325
22. Gas Turbines - Gearboxes and Accessory Drives. . . . . . . . . . . . . . . . . . . . . . . . . 333
23. Gas Turbines - Ignition Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .341
24. Gas Turbines - Auxiliary Power Units and Engine Starting . . . . . . . . . . . . . . . . . . .349
25. Gas Turbines - Fuels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
26. Gas Turbines - Fuel Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373
27. Gas Turbines - Bleed Air. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 389
28. Revision Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .401
29. Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447
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Chapter
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Piston Engines - Introduction
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Terminology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Bernoulli’s Theorem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
A Venturi Tube . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Constant Mass Flow (The Continuity Equation). . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
The Gas Laws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Charles’s Law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
The Combined Gas Laws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
The Application of the Combined Gas Law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Diesel Engines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Terms and Formulae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
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Piston Engines - Introduction
Introduction
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Man’s early attempt at powered flight was thwarted by the lack of a suitable engine to provide on
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the necessary power. The steam engine widely in use at the time was heavy and inefficient. uc
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Combustion took place outside of the engine and much of the heat energy produced was tro
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wasted to the atmosphere. s - I
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In 1862 Beau de Rochas developed an engine where the combustion process took place inside n
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the engine, but in 1876 it was Nikolaus Otto who first succeeded in producing a working engine o
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based on the principle. The principle of operation of the engine is accomplished by inducing a Pi
mixture of air and fuel into a cylinder, which is then compressed by a piston.

The mixture is ignited and the rapid rise in temperature causes the gas pressure in the cylinder
to rise and forces the piston down the cylinder. Linear movement of the piston is converted
into rotary motion by a connecting rod and crankshaft. The burnt gases are then exhausted to
atmosphere. The engine converts heat energy into mechanical energy.
Internal Combustion Engines fall into three main categories, compression ignition engines
(Diesels), two-stroke and four-stroke spark ignition engines and Wankel rotary engines.
These notes cover in detail the construction and operation of the four-stroke engine which is
commonly used in aviation, and generally referred to as the Piston Engine.
Figure 1.1
Figure 1.1
Before we look at the operation and construction of the piston engine an understanding of
the following terms, definitions and theories will be required.
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Piston Engines - Introduction
Terminology
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is Force:
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n A Force is that which, when acting on a body which is free to move, causes it to move, or
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ng conversely, that which stops, or changes the direction of a moving body.
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- In Force is produced when a mass is accelerated. Force = Mass × Acceleration (F = m × a) e.g. A
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ro force moves the piston down the cylinder (Units: newtons or pounds force).
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ion Work:
The Work Done by a force is defined as the product of the Force and the Distance moved in
the direction of the applied force. (Units: joules or foot pounds) e.g. The piston is moved from
the top to the bottom of the cylinder by a force.
Energy:
Energy is the capacity of a body to do work.
Energy comes in many forms: Heat, Light, Chemical, Kinetic, Potential. (Units: joules)
The Law of Conservation of Energy states that: “Energy can be neither created nor destroyed;
only its form may be changed”. The chemical energy of the fuel is converted to heat energy
during combustion in the engine. The engine then converts this to mechanical energy.
Power:
Power is the rate of doing work. Work Done per unit time. (Units joules/second = watts or foot
pound/minute = horsepower) Work is done as the piston moves in the cylinder. It is moved so
many times a minute, and so the power can be measured. The horsepower is a measurement
of power which is equal to 33 000 foot pounds a minute.
Dynamics
Newton’s Laws of Motion deal with the properties of moving objects (or bodies). It is easy to
see a piston or crankshaft move, but air is also a body, and will obey Newton’s Laws. It should
be remembered that air is the working fluid within the engine.
First Law.
“A body will remain at rest or in uniform motion in a straight line unless acted on by an
external force”.
To move a stationary object or to make a moving object change its direction a force must be
applied. The mixture of fuel and air for a piston engine does not want to flow into the cylinder,
a force must make it flow. The piston moving down the cylinder does not want to stop. This
opposition of a body to change its motion or state of rest is called Inertia. Newton’s 1st Law
has no units of measurement. It is a property a body possesses, when stationary or moving.
Newton’s 1st Law is known as the Inertia Law.
Second Law.
“The acceleration of a body from a state of rest, or uniform motion in a straight line, is
proportional to the applied force and inversely proportional to the mass”.
The energy released by the fuel during combustion increases the pressure energy of the air
in the cylinder, and work can be done. The force to move the piston can be controlled by
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