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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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20. copper
21. alloy
22. film cooling
23. orifice
24. chamber throat
25. flux
26. ablative cooling
27. melting
28. vaporization
29. solid rocket booster
30. nozzle
31. radiation cooling
32. ceramic
33. low-heat flux
34. liner
19. камера сгорания
20. абляционное охлаждение
21. твердотопливный ракетный
ускоритель
22. нагрузка
23. медь
24. ракетный двигатель
25. пленочное охлаждение
26. теплопередача
27. входной патрубок охлаждающей
жидкости
28. сопло
29. двигатель
30. сплав
31. технические требования
32. высокая проводимость
33. характеристики
34. регенеративное охлаждение
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)
Task 17. Sum up the text (Task 11).
Task 18. Skim the text and try to understand its subject matter.
Combustion chamber life
Cyclic fatigue of the liner material is one of the life limiting factors for a rocket
engine. During the start-up process the liner is first exposed to liquid hydrogen
which causes the material to shrink and, since the inner copper alloy liner cools
down faster than the outer nickel shell, the fins of the cooling channels are exposed
to severe thermal stresses. At the end of the cool-down the entire chamber inner
shrinks about half the size of the cooling channel wall (Vulcain dimensions). After
successful ignition, the temperature and pressure in the combustion chamber increase
very fast and the copper wall will expand accordingly. Now, the nickel closeout is
cooling by the liquid hydrogen and thus still at cryogenic temperatures. Hence, the
copper has to react to the thermal expansion alone, which poses additional thermal
stresses to the material. With plastic deformation exceeding 3-4% a typical chamber
has a life of less than 20 cycles.
The methods available to predict cyclic life of a combustion chamber are
highly based on experience and experimental data. One reason is still missing
detailed enough initial material properties and their behaviour under operating
conditions. Aside the above mentioned thermal stresses the liner material is exposed
to additional loads, which will have an impact on material properties. First,
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mechanical loads such as static pressure or pressure fluctuations or mechanical
vibrations of various sources, second, material weakening by hydrogen
embrittlement, third, high temperature fatigue or creep, and last but not least a
chemical attack at the surface by OH or other radicals or a simple oxidation through
exposure to oxygen-rich gases. Anyone of these phenomena is difficult to access
quantitatively in separate experiments and, even more important there is no clear
understanding about the interaction of these phenomena. A typical approach for
cyclic life prediction would be to determine the hot gas side and coolant side heat
transfer and then calculate the thermal field and the resulting stresses and strains in
the material iteratively. Then, based on the predicted strains coming from one cyclic
load case the number of cycles to failure is determined applying typical material
failure relations derived from experiments.
Quite often the thermal and mechanical analyses are performed in 2D and for
a stationary thermal field, however recent investigations have shown that 3D
calculations and especially transient thermal analyses are important for reliable
cyclic life predictions. The numerical prediction of total number of cycles to failure
is and will be for quite a while still out of reach for practical applications.
(Oscar J. Haidn Advanced Rocket Engines)
Task 19. Choose the right variant to fill in the gap.
1. During the start-up process the liner is first exposed to liquid hydrogen
which causes the material….
a) to vaporize
b) to shrink
c) to flex
2. Since the inner copper alloy liner cools down faster than the outer nickel
shell, … of the cooling channels are exposed to severe thermal stresses.
a) the fins
b) the ducts
c) the blades
3. After successful ignition, the temperature and pressure in the combustion
chamber … very fast and the copper wall … accordingly.
a) decrease, will expand
b) increase, will expand
c) increase, will shrink
4. The nickel closeout is cooling by … and thus still at cryogenic temperatures.
a) the liquid helium
b) the liquid nitrogen
c) the liquid hydrogen
5. The copper has to react to the thermal expansion alone, which poses
additional thermal … to the material.
a) loads
b) stresses
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c) friction
Peculiarities
Have no infinitive, no gerund, no participles
Have no future tense, no continuous and perfect tenses
Followed by the infinitive without the particle to. Exception:
ought, need, dare and to be and to have used as modal verbs.
Have no ending –(e)s in the third person singular of the
present tense
Form interrogative and negative form of the present and past
tense without the auxiliary verb to do. In the interrogative
form, modal verbs are placed before the subject. In the
negative form, the particle not is used after the modal verb.
Meanings and the use
Can
(could)
Physical or mental ability, capability, possibility depending
on circumstances.
The combination could+Perfect Infinitive indicates that the
action was not carried out.
Equivalent: to be able to, which has all tenses.
Permission.
To express a polite request in interrogative sentences the form
could is used.
To express doubt, astonishment, incredulity in interrogative
and negative sentences.
May be followed by all forms of the infinitive.
The Continuous Infinitive refers to the present. If the verb
has no continuous form, the Simple Infinitive is used in this
case.
The Perfect Infinitive refers to the past.
The form could implies more uncertainty.
6. A typical approach for cyclic life prediction would be to determine the hot gas
side and coolant side … .
a) heat transfer
b) mass transfer
c) heat and mass transfer
Task 20. Collect all the possible supplementary information on the theme of Unit
3 and present it to your groupmates.
UNIT 4. Liquid Propellant Rocket Engine Fundamentals
TEXT: LIQUID PROPELLANT ROCKET ENGINE FUNDAMENTALS
Grammar: Modals
Task 1. Study the peculiarities and meanings of modal verbs.
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May
(might)
Supposition implying uncertainty.
In affirmative and negative sentences:
may+Simple Infinitive mostly refers to the future;
may+Continuous Infinitive refers to the moment of speking;
may+Perfect Infinitive refers to the past.
Possibility depending on circumstances in affirmative
sentences.
The combination might+Perfect Infinitive indicates that the
action was not carried out.
Permission. The combination may+Simple Infinitive is used.
Reproach, disapproval. Only the form might is used.
Must
Obligation, duty, necessity in affirmative and interrogative
sentences. The combination must+Simple Infinitive is used.
Prohibition in negative sentences. The combination
must+Simple Infinitive is used.
Order or advice in affirmative and negative sentences. The
combination must+Simple Infinitive is used.
Supposition implying insurance in affirmative sentences.
must+Simple Infinitive refers to the present if the verb has
no Continuous form.
must+Continuous Infinitive refers to the present.
must+Perfect Infinitive refers to the past.
In the meaning supposition must never refers to the future
and is not used in negative sentences.
To be
Obligation, resulting from a previous agreement, plan,
schedule, time-table, etc.
Order or instruction.
Possibility. The combination to be+Passive Infinitive is
used.
Have two tenses: the Present Simple and the Past Simple.
The present tense of to be is followed only by the Simple
Infinitive.
The combination of the past tense of to be+Perfect
Infinitive indicates that the action was not carried out.
Task 2. Find modal verbs in the English sentences and define their meanings.
Translate the sentences into Russian.
1. In some applications an engine may also include a thrust vector control system,
various instrumentation and residual propellant.
2. Storable propellants are liquid at ambient temperature and can be stored for
long periods in sealed tanks.
3. One of the simplest and most common means of pressurizing the propellants is
to force them out of their respective tanks by displacing them with high-pressure gas.
34
4. A radiation-cooled thrust chamber uses a special high-temperature material,
adjustment – корректировка
aerodynamic surface –
аэродинамическая поверхность
altitude-performance – летные
характеристики
to atomize – распылять
attitude control – управление
положением
boosting – увеличение
control device – устройство
управления
cooling jacket – охлаждающая
рубашка
duty cycle – режим работы
feed mechanism – подающий
механизм
to furnish – обеспечить
guidance – управление, наведение
hardware component – компонент
оборудования
instrumentation – измерительные
приборы, аппаратура
launch vehicle – ракета-носитель
liquid – жидкость
missile warhead – боевая часть ракеты
orbit transfer – переход на новую
орбиту
package – аппаратура
payload – коммерческая нагрузка
piping/plumbing – топливопровод
projectile assist – ракетный ускоритель
метательного снаряда
propellant – топливо для ракетного
двигателя
pump – насос
residual propellant – невыработанное
(остаточное) количество топлива
rocket propulsion system – ракетная
силовая установка
surface launch – наземный пуск,
запуск с поверхности
to tailor – предназначать для
определенных целей
tank – топливный бак
throttle – регулирование тяги
thrust – тяга
thrust-time – тяговая характеристика
thrust vector control system – система
управления вектором тяги
torque – момент
upper stage – разгонный блок, верхняя
ступень, головной блок
valve – клапан
vulnerability – уязвимость
such as niobium metal, which can radiate away its excess heat.
5. A monopropellant may be a mixture of several compounds or it may be a
homogeneous material, such as hydrogen peroxide or hydrazine.
6. If the propulsion system is to be reusable or is part of a manned vehicle, the
feed system becomes more complex and more expensive.
Task 3. Study the following words and word combinations and learn them by heart.
35
Task 4. Translate the words into Russian. Mind suffixes and prefixes.
To suit – suitable, to use – useful, science – scientific, to explore – exploration,
to apply – application, to require – requirement, aircraft – anti-aircraft, vulnerable –
vulnerability, to perform – performance, to store – storage, safe – safety, like –
likely, start – restart, to differ – different, usable – reusable, name – namely, to
adjust – adjustment, to boost – booster, pressure – to pressurize, gas – gaseous,
cooled – uncooled, propulsive – non-propulsive..
Task 5. Read and translate the following international words.
Rocket, system, component, operation, mechanism, energy, structure, control, initiate,
regulate, vector, aerodynamic, navigation, design, term, trajectory, orbit, profile, cycle,
minimum, temperature, impulse, method, modulation, start, cluster, category, maneuver,
reaction, type, to form, product, to absorb, material, niobium, metal, ablative.
Task 6. Translate the sentences into Russian using the terms from Task 3.
1. A rocket engine has all the hardware components and propellants necessary for
its operation, that is, for producing thrust.
2. A rocket engine consists of one or more thrust chambers, one or more tanks to
store the propellants, a feed mechanism to force the propellants from the tanks into
the thrust chamber(s), a power source to furnish the energy for the feed mechanism,
suitable plumbing or piping to transfer the liquids, a structure to transmit the thrust
force, and control devices to initiate and regulate the propellant flow and thus the
thrust.
3. Mission requirements are usually stated in terms of the application (anti-
aircraft rocket, upper stage launch vehicle propulsion, or projectile assist), mission
velocity, the desired flight trajectories (surface launch, orbit transfer, altitudeperformance profile), vulnerability, attitude control torques and duty cycle, minimum
life (during storage or in orbit), or number of units to be built and delivered.
4. There are two categories of rockets, namely those used for boosting a payload
and imparting a significant velocity increase to a payload, and auxiliary propulsion
for trajectory adjustments and attitude control.
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 does a liquid propellant rocket engine consist of?
2. What components may a rocket engine include in some applications?
3. What kind of hardware is used for non-propulsive purposes?
4. What features do types of rocket differ?
5. What ways can liquid propellant rocket engine be classified?
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6. What is the thrust chamber?
7. What major parts does the thrust chamber have?
8. What does a radiation-cooled thrust chamber use?
9. What kinds of thrust chambers are there?
10. What types of feed system are used for liquid propellant rocket engines?
TEXT
Liquid Propellant Rocket Engine Fundamentals
A liquid propellant rocket propulsion system is commonly called a rocket
engine. It has all the hardware components and propellants necessary for its
operation, that is, for producing thrust. It consists of one or more thrust chambers,
one or more tanks to store the propellants, a feed mechanism to force the propellants
from the tanks into the thrust chamber(s), a power source to furnish the energy for
the feed mechanism, suitable plumbing or piping to transfer the liquids, a structure
to transmit the thrust force, and control devices to initiate and regulate the propellant
flow and thus the thrust. In some applications an engine may also include a thrust
vector control system, various instrumentation and residual propellant (trapped in
pipes, valves, or wetting tank walls). It does not include hardware for non-propulsive
purposes, such as aerodynamic surfaces, guidance, or navigation equipment, or the
useful payload, such as a scientific space exploration package or a missile warhead.
The design of any propulsion system is tailored to fit a specific application or
mission requirement. These requirements are usually stated in terms of the
application (anti-aircraft rocket, upper stage launch vehicle propulsion, or
projectile assist), mission velocity, the desired flight trajectories (surface launch,
orbit transfer, altitude-performance profile), vulnerability, attitude control
torques and duty cycle, minimum life (during storage or in orbit), or number of units
to be built and delivered. They include constraints on cost, schedule, operating
conditions (such as temperature limits), storage conditions, or safety rules.
The mission requirements can be translated into rocket engine requirements in
terms of thrust-time profile, propellants, number of thrust chambers, total impulse,
number of restarts, minimum reliability, likely propellant, and engine masses and
their sizes or envelopes. We can do this only if we select several of the key engine
features, such as the feed system, chamber pressure, the method of cooling the thrust
chambers, thrust modulation (restart, throttle, thrust vector control), engine cycle (if
using turbopump feed), and other key design features.
Many different types of rocket range in thrust size from less than 0.01 lbf
(pound force) to over 1.75 million pounds, with one-time operation or multiple starts
(some have over 150,000 restarts), with or without thrust modulation (called
throttling), single use or reusable, arranged as single engines or in clusters of multiple
units. There are two categories, namely those used for boosting a payload and
imparting a significant velocity increase to a payload, and auxiliary propulsion for
trajectory adjustments and attitude control. Liquid propellant rocket engine systems
37
can be classified in several other ways. They can be reusable (like the Space Shuttle
main engine or a booster rocket engine for quick ascent or maneuvers of fighter
aircraft) or suitable for a single flight only (as the engines in the Atlas or Titan launch
vehicles) and they can be restartable, like a reaction control engine, or single firing,
as in a space launch vehicle. They can also be categorized by their propellants,
application, or stage, such as an upper stage or booster stage, their thrust level, and by
the feed system type (pressurized or turbopump). The thrust chamber or thruster is
the combustion device where the liquid propellants are metered, injected, atomized,
mixed, and burned to form hot gaseous reaction products, which in turn are
accelerated and ejected at a high velocity to impart a thrust force. A thrust chamber
has three major parts: an injector, a combustion chamber, and a nozzle. In a cooled
thrust chamber, one of the propellants (usually the fuel) is circulated through cooling
jackets or a special cooling passage to absorb the heat that is transferred from the hot
reaction gases to the thrust chamber walls. A radiation-cooled thrust chamber uses a
special high-temperature material, such as niobium metal, which can radiate away its
excess heat. There are uncooled or heat-absorbing thrust chambers, such as those
using ablative materials. There are two types of feed systems used for liquid
propellant rocket engines: those that use pumps for moving the propellants from their
flight vehicle tanks to the thrust chamber, and those that use high-pressure gas for
expelling or displacing their propellants from their tanks.
(Sutton, George P. & Biblarz, Oscar Rocket Propulsion Elements: an introduction to
the engineering of rockets)
Task 8. Find in the text the English equivalents for the following words and word
combinations.
Жидкостный ракетный двигатель, ракетная силовая установка, подающий
механизм, развитие тяги, топливный бак, сила тяги, камера сгорания, источник
питания, навигационное оборудование, требования к полету, зенитная ракета,
скорость полета, повторный запуск, минимальный ресурс, безопасность,
надежность, конструктивные особенности, регулирование тяги, одноразовый,
вспомогательная силовая установка, многоразовый, двигатель ракеты-носителя,
выведение на орбиту, истребитель, двигатель реактивной системы управления,
одиночный пуск, ракета-носитель, режим тяги, стартовая ступень, находящийся
под избыточным давлением, сопло, канал охлаждения, избыточная теплота,
насос.
Task 9. Complete the sentences with the appropriate endings.
1. A liquid propellant rocket propulsion system is commonly called … .
а) a powerplant
b) a rocket engine
2. The hardware components and propellants are necessary for … .
a) regulating thrust
b) producing thrust
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3. The design of any propulsion system is tailored to fit … .
There are two types of feed systems used
for liquid propellant rocket engines: …
in terms of the application, mission
velocity, the desired flight trajectories,
vulnerability, attitude control torques and
duty cycle, minimum life, or number of
units to be built and delivered.
Liquid propellant rocket engine systems
can be …
hardware for non-propulsive purposes,
such as aerodynamic surfaces, guidance,
or navigation equipment, or the useful
payload, such as a scientific space
exploration package or a missile
warhead.
Many different types of rocket range in
…
categorized by their propellants,
application, or stage, such as an upper
stage or booster stage, their thrust level,
and by the feed system type.
Mission requirements are usually stated
…
one or more thrust chambers, one or more
tanks, a feed mechanism, a power source,
suitable plumbing, a structure to transmit
the thrust force, and control devices.
Mission requirements include constraints
…
those that use pumps for moving the
propellants from their flight vehicle tanks
to the thrust chamber, and those that use
high-pressure gas for expelling or
displacing their propellants from their
tanks.
a) mission requirement
b) engine requirement
4. Many different types of rocket range in thrust size from ….
a) less than 0.1 lbf to over 1.75 million pounds
b) less than 0.01 lbf to over 1.75 million pounds
5. A thrust chamber has three major parts: … .
a) an injector, a combustion chamber, and a nozzle
b) an injector, a combustion chamber, and a feed system
6. A radiation-cooled thrust chamber uses a special … .
a) high-temperature material
b) high-resistant material
7. There are uncooled or heat-absorbing thrust chambers, such as those … .
a) using heat absorbing materials
b) using ablative materials
Task 10. Complete the sentences with appropriate endings.
39
A rocket engine consists of …
on cost, schedule, operating conditions
(such as temperature limits), storage
conditions, or safety rules.
A rocket engine does not include …
thrust size from less than 0.01 lbf to over
1.75 million pounds, with one-time
operation or multiple starts, with or
without thrust modulation, single use or
reusable, arranged as single engines or in
clusters of multiple units.
Task 11. Read the following text and try to understand its subject matter.
Translate the text into Russian. Use the dictionary if necessary.
The propellants, which are the working substance of rocket engines, constitute the
fluid that undergoes chemical and thermodynamic changes. The term liquid
propellant embraces all the various liquids used and may be one of the following:
1. Oxidizer (liquid oxygen, nitric acid, etc.)
2. Fuel (gasoline, alcohol, liquid hydrogen, etc.).
3. Chemical compound or mixture of oxidizer and fuel ingredients, capable of
self-decomposition.
4. Any of the above, but with a gelling agent.
A bipropellant rocket unit has two separate liquid propellants, an oxidizer and a
fuel. They are stored separately and are not mixed outside the combustion chamber.
The majority of liquid propellant rockets have been manufactured for bipropellant
applications. A monopropellant contains an oxidizing agent and combustible matter
in a single substance. It may be a mixture of several compounds or it may be a
homogeneous material, such as hydrogen peroxide or hydrazine. Monopropellants are
stable at ordinary atmospheric conditions but decompose and yield hot combustion
gases when heated or catalyzed. A cold gas propellant (e.g., nitrogen) is stored at
very high pressure, gives a low performance, allows a simple system and is usually
very reliable. It has been used for roll control and attitude control. A cryogenic
propellant is liquified gas at low temperature, such as liquid oxygen (-183°C) or
liquid hydrogen (-253°C). Provisions for venting the storage tank and minimizing
vaporization losses are necessary with this type. Storable propellants (e.g., nitric acid
or gasoline) are liquid at ambient temperature and can be stored for long periods in
sealed tanks. Space storable propellants are liquid in the environment of space; this
storability depends on the specific tank design, thermal conditions, and tank pressure.
An example is ammonia. A gelled propellant is a thixotropic liquid with a gelling
additive. It behaves like a jelly or thick paint. It will not spill or leak readily, can flow
under pressure, will burn, and is safer in some respects.
(Sutton, George P. & Biblarz, Oscar Rocket Propulsion Elements: an introduction to
PROPELLANTS
the engineering of rockets)
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