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Файл:Jet Propulsion Engine Fundamentals английский язык для студентов специальности «Проектирование авиационных и ракетных двигателей». Учебное пособие
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Task 15. Look through the texts (Task 7, 11) and find key sentences in each
paragraph.
Task 16. Write a summary to the text (Task 7) using the following expressions
and key sentences.
TO BEGIN WITH:
1. The text represents …
2. The text under consideration describes …
3. The text begins with the description …
4. The text is devoted to the problem of …
5. The text centers around / describes …
6. The text deals with (the problem of) …
7. The text centers round the problem of …
8. The author of the text describes the problem of …
9. I can understand from the text that …
TO CONTINUE:
1. The author attracts our attention to …
2. The author further says that …
3. The idea is known to have …
4. It is understood that …
5. … is thought to be a good example of …
6. It is stated in the text that …
7. Great importance is also attached to …
8. We shouldn’t overlook that …
9. It must also be mentioned that …
10. In my opinion …
11. From my point of view …
12. To my mind …
13. According to the author’s opinion …
14. Among other problems the text raises the problem of …
15. The problem described in the text is of great interest (importance) to …
TO FINISH WITH:
1. In conclusion it is written / the author writes …
2. To sum up the author relaters to the fact …
3. The author praises / criticizes / approves …
4. To sum the given information up …
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5. Summing the text up (summing it up) …
6. On the whole we can conclude …
7. Having analysed the information it is possible to say …
8. We can come to the conclusion …
9. Finally the author sums up / summarizes …
10. I completely agree with the author that …
Task 17. Sum up the text (Task 11).
Task 18. Skim the text and try to understand its subject matter.
The internal combustion engine is a heat engine that converts chemical energy in
a fuel into mechanical energy, usually made available on a rotating output shaft.
Chemical energy of the fuel is first converted to thermal energy by means of
combustion or oxidation with air inside the engine. This thermal energy raises the
temperature and pressure of the gases within the engine, and the high-pressure gas
then expands against the mechanical mechanisms of the engine. This expansion is
converted by the mechanical linkages of the engine to a rotating crankshaft, which is
the output of the engine. The crankshaft, in turn, is connected to a transmission and/or
power train to transmit the rotating mechanical energy to the desired final use. For
engines this will often be the propulsion of a vehicle (i.e., automobile, truck,
locomotive, marine vessel, or airplane). Other applications include stationary engines
to drive generators or pumps, and portable engines for things like chain saws and
lawn mowers. Most internal combustion engines are reciprocating engines having
pistons that reciprocate back and forth in cylinders internally within the engine.
Reciprocating engines can have one cylinder or many, up to 20 or more. The
cylinders can be arranged in many different geometric configurations. Sizes range
from small model airplane engines with power output on the order of 100 watts to
large multicylinder stationary engines that produce thousands of kilowatts per
cylinder. There are so many different engine manufacturers, past, present, and future,
that produce and have produced engines which differ in size, geometry, style, and
operating characteristics that no absolute limit can be stated for any range of engine
characteristics (i.e., size, number of cylinders, strokes in a cycle, etc.).
Early development of modern internal combustion engines occurred in the latter
half of the 1800s and coincided with the development of the automobile. History
records earlier examples of crude internal combustion engines and self-propelled road
vehicles dating back as far as the 1600s. Most of these early vehicles were steamdriven prototypes which never became practical operating vehicles. Technology,
roads, materials, and fuels were not yet developed enough. Very early examples of
heat engines, including both internal combustion and external combustion, used gun
powder and other solid, liquid, and gaseous fuels. Major development of the modern
steam engine and, consequently, the railroad locomotive occurred in the latter half of
the 1700s and early 1800s. By the 1820s and 1830s, railroads were present in several
countries around the world.
(from Willard W. Pulkrabek Engineering Fundamentals of the Internal
Combustion Engine)
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Task 19. Choose the right variant to fill in the gap.
1. The internal combustion engine is __________ that converts chemical energy
in a fuel into mechanical energy.
a) a steam engine
b) a pneumatic engine
c) a heat engine
2. The thermal energy __________ the temperature and pressure of the gases
within the engine, and the high-pressure gas then _________ against the mechanical
mechanisms of the engine.
b) raises, pressurizes
b) raises, expands
c) reduces, expands
3. ____________ is connected to a transmission and/or power train to
transmit the rotating mechanical energy to the desired final use.
a) The crankshaft
b) The rod
c) The turbine
4. Most internal combustion engines are __________ engines having
pistons that reciprocate back and forth in cylinders internally within the engine.
a) pneumatic
b) reciprocating
c) rotary
5. Early development of modern internal combustion engines occurred in
the__________.
a) latter half of the 1600s
b) first half of the 1800s
c) latter half of the 1800s
6. Very early examples of__________, including both internal combustion
and external combustion, used gun powder and other solid, liquid, and gaseous fuels.
a) jet engines
b) chemical engines
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c) heat engines
The function of the Absolute
Participial Construction
Example
time
Things packed, we started off.
cause or reason
The situation being so grave, urgent
measures had to be taken.
manner or attending circumstances
The research group could not go on with
the experiments without their plan being
approved by the scientific supervisor.
Task 20. Collect all the possible supplementary information on the theme of Unit
1 and present it to your groupmates.
UNIT 2. Gas Turbine
TEXT: GAS TURBINE
Grammar: Absolute Participial Construction
Task 1. Study the functions of the Absolute Participial Construction in the
English sentences and translate them into Russian.
Task 2. Find Absolute Participial Construction in the English sentences and
translate them into Russian. Pay attention to the ways they are expressed in Russian
sentences.
1. Some new devices having been obtained, the researchers could make more
complex experiments.
2. It being late, the designers decided to stop working.
3. All machines have energy loss, some energy being converted into
useless heat due to friction.
4. Gas turbine-propeller engines are designed to deliver auxiliary jet thrust
from the exhaust gases in addition to the propeller thrust, the usual proportions being
80 per cent propeller thrust and 20 per cent auxiliary jet thrust.
5. In many respects the turbine for gas turbine-propeller engines or turbo-jet
engines is quite similar to the conventional steam turbine, the major difference being
in the metallurgy, the means provided for cooling the bearings and highly stressed
parts, and in the constructional features to safeguard against thermal distortion.
6. The turbine blades may be either solid or hollow, the type of construction
being influenced by the material selected for their manufacture.
Task 3. Study the following words and word combinations and learn them by heart.
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air compressor – воздушный
компрессор
auxiliaries – вспомогательные
устройства
bearing - подшипник
blade - лопатка
bucket temperature – температура
лопасти
constructional feature –
конструктивная особенность
deliver – освобождать, избавлять
drive – приводить в движение
exhaust gases – выхлопные газы
frontal area – лобовая площадь
furnish – обеспечивать, выдавать
jet – реактивный
means - устройства
power output – выходная мощность
propeller – пропеллер, воздушный
винт
propeller thrust – тяга воздушного
винта
provided for - предусмотренный
reliability - надежность
rim speed – окружная скорость
safeguard – предохранять
serviceability – эксплуатационная
пригодность, ремонтопригодность
shaft power – мощность на валу;
мощность, передаваемая валом
steam turbine – паровая турбина
strength – прочность, предел
прочности
stress - напряжение
sufficient – достаточный
supercharger - нагнетатель
sustained period – длительный,
продолжительный период
thermal distortion – температурная
деформация
thermal jet engine – воздушно-
реактивный двигатель
thrust - тяга
turbine-propeller engine –
турбовинтовой двигатель
Task 4. Translate the words into Russian. Mind suffixes and prefixes.
To propel – propeller; to compress – compressor ; to add – addition; particular –
particularly; help – helpful; to develop – development; high – highly; to apply – application;
construction – constructional; to evaluate- evaluation; to distort – distortion; equal – equally;
to require – requirement; efficient – efficiency; reliable – reliability.
Task 5. Read and translate the following international words.
Turbine, component, gas, thermal, information, decade, metallurgy, temperature, rotor,
diameter, period, disk, maximum, limit, characteristic, material, compromise, design,
mass, acoustic, critical, disk, method, metallurgical, problem, gradient, natural,
function, characteristics, crystal, structure, compressor, type.
Task 6. Translate the sentences into Russian using the terms from Task 3.
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1. It is required to furnish only sufficient power to drive the air compressor and
the auxiliaries.
2. Usually thrust is comprised of 80 per cent propeller thrust and 20 per cent
auxiliary jet thrust.
3. The experience gathered in the development of turbo-superchargers and also
steam turbines for high-pressure and high-temperature applications is particularly
helpful to the development of turbines which operate with highly heated gases.
4. The basic requirements for the turbine are the same for either type of engine.
5. There is a lower limit to the rim speed imposed by the dictates of high
efficiency which improves with rim speed.
Task 7. Read the following text carefully paying attention to the words in bold
type. Try to understand the subject matter of the text and be ready to answer the
following questions.
1. What is a major component common to the gas turbine-propeller engine,
and to the thermal jet engine?
2. What is the turbine intended for?
3. What does the thermal jet engine require?
4. What are gas turbine-propeller engines designed for?
5. What differs the turbine for gas turbine-propeller engines or turbo-jet
engines from the conventional steam turbine?
6. What are the principle requirements for the turbine?
7. What is light weight secured by?
8. What does the maximum rim speed depend on?
9. What determines the choice of rim speed?
TEXT
GAS TURBINE
The turbine is a major component common to the gas turbine-propeller engine,
and to the thermal jet engine. In the gas turbine-propeller engine the turbine must
develop the shaft power for driving the air compressor, propeller, and the
auxiliaries. In the thermal jet engine, however, it is required to furnish only
sufficient power to drive the air compressor and the auxiliaries. In general, gas
turbine-propeller engines are designed to deliver auxiliary jet thrust from the
exhaust gases in addition to the propeller thrust, the usual proportions being 80 per
cent propeller thrust and 20 per cent auxiliary jet thrust. Particularly helpful to the
development of turbines which operate with highly heated gases is the experience
gathered in the development of turbo-superchargers and also steam turbines for
high-pressure and high-temperature applications. In many respects the turbine for gas
turbine-propeller engines or turbo-jet engines is quite similar to the conventional
16
steam turbine, the major difference being in the metallurgy, the means provided for
cooling the bearings and highly stressed parts, and in the constructional features to
safeguard against thermal distortion.
The basic requirements for the turbine are the same for either type of engine. The
following remarks apply equally well to the turbines for turbojet and turboprop
engines. The principal requirements are: (a) light weight; (b) small frontal area; (c)
high efficiency; (d) ability to operate for sustained periods at high temperature; and
(e) reliability and serviceability.
Light weight is secured by operating the turbine rotor with the highest permissible
rim speed, using small-diameter rotors. Since the stresses in a given turbine disk
increase approximately as the square of the rim speed, the maximum rim speed is
limited by strength considerations, which are governed by the stress characteristics
of the disk and blade materials at the operating temperature. Although low rim
speeds are desirable from a stress standpoint, there is a lower limit to the rim speed
imposed by the dictates of high efficiency which, in general, improves with rim
speed. Since the turbine efficiency improves, in general, with increasing rim speed
and permits using lower bucket temperatures for the same power output, the
choice of rim speed is a compromise between allowable stress and turbine efficiency.
The rim speeds of most turbojet turbines range from 820 to 1000 fps.
(Kates E.K. Diesel and High Compression Gas Engines)
Task 8. Find in the text the English equivalents for the following words and word
combinations.
Газотурбинный турбовинтовой двигатель, воздушно-реактивный двигатель,
выдавать, достаточная мощность, дополнительная реактивная тяга, выхлопные
газы, тяга воздушного винта, разработка, сильно нагретые газы,
турбонагнетатель, высоконапряженные детали, конструктивные особенности,
предохранять от, температурная деформация, ротор турбины, турбинный диск,
прочностные характеристики, рабочая температура, температура лопасти,
допустимое напряжение, КПД турбины.
Task 9. Fill in the gaps with prepositions and translate the sentences into
Russian.
1. The turbine is a major component common … the gas turbine-propeller engine.
2. In the gas turbine-propeller engine the turbine must develop the shaft power …
driving the air compressor, propeller, and the auxiliaries.
3. Gas turbine-propeller engines are designed to deliver auxiliary jet thrust … the
exhaust gases … addition … the propeller thrust.
4. Particularly helpful … the development … turbines which operate … highly
heated gases is the experience gathered … the development … turbo-superchargers
and also steam turbines … high-pressure and high-temperature applications.
5. The basic requirements … the turbine are the same … either type … engine.
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6. Light weight is secured … operating the turbine rotor … the highest
1. Light weight is secured by …
1. the turbine must develop the shaft
power for driving the air compressor,
propeller, and the auxiliaries.
2. In many respects the turbine for gas
turbine-propeller engines or turbo-jet
engines is …
2. to deliver auxiliary jet thrust from the
exhaust gases in addition to the propeller
thrust.
3. Since the turbine efficiency improves,
in general, with increasing rim speed and
permits using lower bucket temperatures
for the same power output, …
3. there is a lower limit to the rim speed
imposed by the dictates of high efficiency
which, in general, improves with rim
speed.
4. In the gas turbine-propeller engine …
4. the choice of rim speed is a
compromise between allowable stress
and turbine efficiency.
5. Since the stresses in a given turbine
disk increase approximately as the square
of the rim speed, …
5. quite similar to the conventional steam
turbine.
6. Although low rim speeds are desirable
from a stress standpoint, …
6. operating the turbine rotor with the
highest permissible rim speed, using
small-diameter rotors.
7. Gas turbine-propeller engines are
designed …
7. the maximum rim speed is limited by
strength considerations, which are
governed by the stress characteristics of
the disk and blade materials at the
operating temperature.
permissible rim speed, using small-diameter rotors.
7. The maximum rim speed is limited … strength considerations, which are
governed … the stress characteristics … the disk and blade materials … the operating
temperature.
8. Although low rim speeds are desirable … a stress standpoint, there is a lower
limit … the rim speed imposed … the dictates … high efficiency which, in general,
improves … rim speed.
Task 10. Complete the sentences with appropriate endings.
Task 11. Read the following text and try to understand its subject matter.
Translate the text into Russian. Use the dictionary if necessary.
The general design of the turbine passages is based primarily on considerations
18
which are mainly fluid dynamical (гидрогазодинамический). The flow
conditions must be so designed that, for the required thrust output (тяга двигателя)
and mass flow (расход массы) of gas, the acoustic velocity (unity Mach number)* is
not reached at the outlet (выпускное отверстие) from the buckets (or in the ducting
downstream leading the exhaust gases away from the turbine, or in the exhaust
nozzle (выходное сопло)), for choking of the flow (запирание потока) occurs if
the Mach number in these flow passages attains the value unity (единица значения).
The critical Mach number is based on the axial (осевой) velocity of the gas in the
exit annulus (кольцо) from the turbine. The possibility of attaining unity Mach
number in the outlet from the turbine buckets (турбинные лопатки) is a
consideration to be investigated in Rateau stage turbines.
Disk and rim failures (повреждения) in turbo-jet turbines did occur in the early
development stages of this propulsion engine (тяговый двигатель). They have now
been overcome by the application of such methods as improved gas seals
(газонепроницаемое уплотнение), the incorporation of methods for cooling the
disk, and improved metallurgy. One of the major factors has been a better understanding of the metallurgical problem. Research has shown that if the disk operates
with high temperatures or steep temperature gradients (крутой температурный
коэффициент) it is likely to develop plastic deformation. If this occurs the stress
distribution (распределение напряжений) can no longer be based on conventional
elastic theory (теория упругих деформаций), and when the disk cools off after
operating it is subjected to large residual (остаточный) stresses. As a consequence
of the residual stresses there is a change in the natural vibration frequencies, which
are functions of the stress conditions. Furthermore, successive periods of plastic
strain (пластическая деформация), cooling, and then heating again modify the
stress-strain characteristics (зависимость между напряжениями и деформацией)
of the disk material and may lead to changes in its crystal structure. By applying the
remedies (способы устранения неисправностей) mentioned above these
difficulties can be avoided.
In turbo-jet engines employing a centrifugal (центробежный) compressor, the
turbine imposes no problem in the securing of small frontal area. The frontal area of
the turbine is much smaller than that of the compressor and combustion chamber
assembly (камера сгорания) and has little influence upon the overall size in that
type of application. Where the turbine drives an axial-flow (осевой) compressor the
frontal areas of the turbine and compressor become more nearly equal.
The turbine blades may be either solid or hollow (полый), the type of
construction being influenced by the material selected for their manufacture. The
hollow blade offers the advantages of being adapted to cooling by flowing cold air
through its interior (внутренняя сторона) and of reducing weight. The walls of the
blade are usually tapered (конический) so that the outer extremity (конец), where
the stress vanishes, is quite thin. The greatest benefit derived from cooling is at the
root (хвостовик, ножка) of the blade where the stresses are high; the outer edge,
because of its small stress, may be allowed to run hot.
* Mach number (M) — число Маха, т. е. отношение скорости движения потока к
19
скорости звука при данных условиях (движения потока).
(Kates E.K. Diesel and High Compression Gas Engines)
Task 12. Answer the questions and use them as a plan for retelling the text.
1. What is the general design of the turbine passages based on?
2. What way must the flow conditions be designed?
3. What is the critical Mach number based on in the exit annulus from the
turbine?
4. How have disk and rim failures now been overcome?
5. When does disk develop plastic deformation?
6. What is a consequence of the residual stresses?
7. What modifies the stress-strain characteristics of the disk material and may
lead to changes in its crystal structure?
8. Why does the turbine impose no problem in the securing of small frontal area
in turbo-jet engines employing a centrifugal compressor?
9. What does the hollow blade offer?
10. What size are the walls of the blade?
Task 13. Translate the following sentences into English.
1. Турбина является основным компонентом газотурбинного турбовинтового
двигателя.
2. Лобовая площадь турбины гораздо меньше лобовой площади турбины и
блока камеры сгорания.
3. Работа диска в условиях высокой температуры или крутого
температурного градиента приводит к образованию пластической деформации.
4. Турбина должна развивать мощность на валу, необходимую для приведения в
движение воздушного компрессора, воздушного винта и вспомогательных устройств.
5. Газотурбинный турбовинтовой двигатель позволяет высвобождать
дополнительную реактивную тягу из выхлопных газов в дополнение к тяге
воздушного винта.
6. По многим параметрам турбина для газотурбинных турбовинтовых двигателей
или турбореактивных двигателей подобна обычной паровой турбине.
7. Остывая после работы, диск подвергается высоким остаточным
напряжениям.
8. Небольшой вес обеспечивается работой ротора турбины с максимально
разрешенной окружной скоростью и использованием роторов малого диаметра.
9. Следствием остаточных напряжений является изменение частот
естественной вибрации.
10. Максимальная окружная скорость ограничивается характеристиками
напряжения материалов диска и лопатки при рабочей температуре.
11. Лопасти турбины могут быть твердотельными или полыми.
12. Стенки лопасти обычно сужаются так, что на внешнем конце, где
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