Обучение чтению литературы на английском языке по направлению подготовки «Ракетные двигатели»
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Тематика:
Английский язык
Год издания: 2016
Кол-во страниц: 40
Дополнительно
Вид издания:
Учебное пособие
Уровень образования:
ВО - Специалитет
ISBN: 978-5-7038-4379-6
Артикул: 840477.01.99
Издание включает три модульных блока и три дополнительных текста. Каждый блок содержит по три текста из англоязычной научно-технической литературы, словарь с активной лексикой по изучаемой теме, лексико-грамматические упражнения, направленные на развитие и закрепление навыков понимания и перевода оригинальных текстов, а также умения устного общения на профессиональные темы.
Для студентов старших курсов, обучающихся по направлению подготовки «Ракетные двигатели».
Тематика:
ББК:
УДК:
- 6297: Авиация и космонавтика. Летательные аппараты. Ракетная техника. Космическая техника
- 811111: Английский язык
ОКСО:
- ВО - Специалитет
- 24.05.02: Проектирование авиационных и ракетных двигателей
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Московский государственный технический университет имени Н.Э. Баумана Т.И. Кульбакова, А.Г. Котина Обучение чтению литературы на английском языке по направлению подготовки «Ракетные двигатели» Учебное пособие
УДК 802.0 ББК 81.2 Англ.-923 К90 Издание доступно в электронном виде на портале ebooks.bmstu.ru по адресу: http://ebooks.bmstu.ru/catalog107/book1410.html Факультет «Лингвистика» Кафедра «Английский язык для машиностроительных специальностей» Рекомендовано Редакционно-издательским советом МГТУ им. Н.Э. Баумана в качестве учебного пособия Кульбакова, Т. И. Обучение чтению литературы на английском языке по направлению подготовки «Ракетные двигатели» : учебное пособие / Т. И. Кульбакова, А. Г. Котина. — Москва : Издательство МГТУ им. Н. Э. Баумана, 2016. — 39, [1] с. : ил. ISBN 978-5-7038-4379-6 Издание включает три модульных блока и три дополнительных текста. Каждый блок содержит по три текста из англоязычной научно-технической литературы, словарь с активной лексикой по изучаемой теме, лексикограмматические упражнения, направленные на развитие и закрепление навыков понимания и перевода оригинальных текстов, а также умения устного общения на профессиональные темы. Для студентов старших курсов, обучающихся по направлению подготовки «Ракетные двигатели». УДК 802.0 ББК 81.2 Англ.-923 МГТУ им. Н.Э. Баумана, 2016 Оформление. Издательство ISBN 978-5-7038-4379-6 МГТУ им. Н.Э. Баумана, 2016 К90
ПРЕДИСЛОВИЕ Учебное пособие подготовлено в соответствии с учебными программами МГТУ им. Н.Э. Баумана. Оно предназначено для аудиторных занятий студентов старших курсов факультета «Энергомашиностроение» при обучении чтению и устной речи на английском языке под руководством преподавателя. Материал издания также может быть использован студентами для самостоятельной работы. Пособие состоит из трех модульных блоков и трех дополнительных текстов. В каждый блок включены оригинальные тексты из англоязычной научно-технической литературы, разнообразные лексико-грамматические упражнения, направленные на отработку языковых конструкций, которые характерны для научнотехнической литературы, а также упражнения на развитие коммуникативных навыков и словари, содержащие активную лексику и специальную терминологию по изучаемой в техническом вузе специальности. Задания, направленные на развитие устной речи, помогут студентам подготовить презентации, выступить с сообщениями, принять участие в обсуждениях.
UNIT 1 1. Read and learn the following words and word combinations: configuration — структура, конструкция, расположение, компоновка nozzle — сопло, форсунка propellant — ракетное топливо thrust — тяга, сила тяги mass flow rate — удельный массовый расход, массовая ско рость потока mass ratio — отношение масс, относительный массовый расход (в потоке) degradation — старение материала, ухудшение качества поверхности turbine — турбина throat — горловина, соединительная часть evaporation — испарение cryogenics — физика низких температур, криогенная техника hypergolic propellant — самовоспламеняющееся топливо swirl injector — вихревая форсунка orifice — отверстие plumbing — система труб coaxial injector — форсунка с коаксиальным впрыском annular aperture — кольцевая апертура, диафрагма cross section — поперечное сечение igniter — воспламенитель motive power — движущая сила 2. Give synonyms to the words below. Restriction, plumbing, issue, contraction, pipeline, problem, ensure, fulfil, enable, guarantee, implement, allow. 3. Translate the following word combinations into Russian. Majority of large liquid propellant engine systems, important consideration, fluid flow laws, combustion chamber design, low specific
impulse, hypergolic propellant combinations, high thrust engines, low thrust engines, hypersonic airbreathing propulsion system task. 4. Find English equivalents of the following phrases. Двигатели малой тяги, еще один недостаток, газ под высоким давлением, прочные стенки, топливо подается в, прогорание. A further penalty, thermal degradation, strong walls, the propellant is fed to, low-thrust engines, high-pressure gas. 5. Read and translate Text 1A. Answer the questions. 1. What does the liquid propellant rocket engine system consist of? 2. How is the propellant fed into the combustion chamber? 3. Where is thrust developed? Text 1A The basic configuration of the liquid propellant engine A liquid propellant rocket engine system comprises the combustion chamber, nozzle, and propellant tanks, together with the means to deliver the propellants to the combustion chamber. In the simplest system, the propellant is fed to the combustion chamber by static pressure in the tanks. High-pressure gas is introduced to the tank, or is generated by evaporation of the propellant, and this forces the fuel and oxidizer into the combustion chamber. The thrust of the engine depends on the combustion chamber pressure and, of course, on the mass flow rate. It is difficult to deliver a high flow rate at high pressure using static tank pressure alone, so this system is limited to low-thrust engines for vehicle upper stages. There is a further penalty, because the tanks need to have strong walls to resist the high static pressure, and this reduces the mass ratio. The majority of large liquid propellant engine systems use some kind of turbo-pump to deliver propellants to the combustion chamber. The most common makes use of hot gas, generated by burning some of the propellant, to drive the turbine. Since high combustion temperature is needed for high thrust, cooling is an important consideration in order to avoid thermal degradation of the combustion chamber and nozzle. The design of combustion chambers and nozzles has to take this into account. In addition, safe ignition and smooth burning of the propellants is vital to the correct performance of the rocket engine.
6. Translate the sentences into Russian paying attention to Infinitive. 1. Energia was equipped with a side-mounted cylindrical cargo carrier that could be configured as a payload to be delivered to the Moon or Mars. 2. So if the weight of the object to be delivered to higher orbit is one unit, then the mass of the system in LEO times the orbital altitude mass ratio is the total mass of the system required to change altitude. 3. Even with this information, there is much more to be learned from exploring the Moon and understanding its geology and structure. 4. The danger exists of an accident, such as that of the Challenger's, in which the conventional launcher could explode, damaging the reactor to be orbited and spreading fissile material from the damaged reactor stored in the payload bay either in the atmosphere or on the ground. 5. Following the launch of Sputnik by the Soviet Union, President Eisenhower’s administration elicited proposals to launch a satellite into orbit. 6. We know the questions to ask about underlying materials and structures and about samples when they can be obtained from the surface of Earth’s sister planet. 7. At the same time, the Australian launch range was abandoned in favor of a new launch center to be constructed in French Guiana. 8. Unfortunately, the lessons to be learned from the Europe 1 failures were ignored. 9. This decision provided a substantial growth potential for European satellites and demonstrated a determination to design the Ariane launcher for an extended lifetime. 7. Read and translate Text 1B. Discuss the questions. 1. What are the functions of the injector? 2. What does the choice of the injector location depend on? 3. What is necessary to provide efficient injection? Text 1B The combustion chamber and nozzle Part 1 The combustion chamber and the nozzle form the main part of the engine, wherein the thrust is developed. The combustion chamber comprises the injector through which the propellants enter, the vaporization, mixing, and combustion zones, and the restriction
leading to the nozzle. The throat is properly part of the nozzle. The combustion chamber has to be designed so that the propellants vaporize and mix efficiently, and so that the combustion is smooth. It must also withstand the high temperature and pressure of combustion, and in some cases cooling of the chamber walls is arranged. The combustion chamber joins smoothly on its inner surface to the nozzle, and the restriction in the combustion chamber and the nozzle together form the contraction-expansion or de Laval nozzle. The shape is defined by the thermodynamic and fluid flow laws together with the design requirements. Injection. The injector has to fulfil three functions: it should ensure that the fuel and oxidizer enter the chamber in a fine spray, so that evaporation is fast; it should enable rapid mixing of the fuel and oxidizer, in the liquid or gaseous phase; and it should deliver the propellants to the chamber at high pressure, with a high flow rate. The specific injector design has to take into account the nature of the propellants. For cryogenic propellants such as liquid oxygen and liquid hydrogen, evaporation into the gaseous phase is necessary before ignition and combustion. In this case a fine spray of each component is needed. The spray breaks up into small droplets which evaporate, and mixing then occurs between parallel streams of oxygen and hydrogen. For hypergolic or self-igniting propellants such as nitrogen tetroxide and UDMH, the two components, which react as liquids at room temperature, should come into contact early, and impinging sprays or jets of the two liquids are arranged. In some cases pre-mixing of the propellants in the liquid form is needed, and here the swirl injector is used, in which the propellants are introduced together into a mixing tube. They enter the chamber pre-mixed, and are exposed to the heat of combustion. In all cases, the heat of the gases undergoing combustion is used to evaporate the propellant droplets. The heat is transferred to the droplets by radiation, and conduction through the gas. The propellant passing through the combustion chamber has a low velocity, and does not speed up until it reaches the nozzle. The requirement for a fine spray, together with a high flow rate, is contradictory, and can be realized only by making up the injector of many hundreds of separate fine orifices. Good mixing requires that adjacent jets consist of fuel and oxidizer. Thus, the hundreds of orifices have to be fed by complex plumbing, with the piping for two com
ponents interwoven. The design of the injector is a major issue of combustion chamber design. Types of Injector. The simplest type of injector is rather like a shower head, except that adjacent holes inject fuel and oxidant so that the propellants can mix. Improved mixing can be achieved with the use of a coaxial injector. Here each orifice has the fuel injected through an annular aperture which surrounds the circular oxidant aperture, and this is repeated many times to cover the area of the injector. The above injectors are used for propellants which react in the vapour phase. The fine sprays quickly form tiny droplets, which also evaporate quickly. The first is designed to make sure that propellants mix as early as possible, while still in the liquid phase, and is useful for hypergolic propellant combinations. In the second form, jets of the same propellant impinge on one another. This is useful where fine holes are not suitable. The cross section of the jets can be larger, while the impinging streams cause the jets to break up into droplets. The injector can be located across the back of the combustion chamber, or it can be located around the cylindrical wall of the rear end of the combustion chamber. The choice depends on convenience of plumbing, and the location of the igniter, where used. For example, the HM7-B cryogenic engine, used to power the third stage of Ariane 4, uses a frontal injector unit with 90 coaxial injector sets which feed the liquid oxygen and liquid hydrogen into the combustion chamber at a pressure of 35 bar. In contrast, the Viking engine used to power the first stage of Ariane 4 uses 216 parallel injector pairs set in six rows around the wall of the combustion chamber, and these feed the hypergolic propellants UMDH and nitrogen tetroxide into the chamber. The number of injectors controls the flow rate and for high thrust engines many more is used. For the Vulcan engine, used as the single motive power for the Ariane 5 main stage, 516 coaxial injectors are used, delivering liquid hydrogen and liquid oxygen at 100 bar. This engine generates more than 1 mega-Newton of thrust. 8. Translate the sentences paying attention to Complex Subject. 1. China is likely to develop a strong manned space programme. 2. Wan Hu is said to have attached 47 rockets to a bamboo chair, with the purpose of ascending into heaven. 3. Powers much above 100 kW are unlikely to be achievable with the current technology. 4. The graphite itself appears to have suffered cracking and rupture once the
protective surface had been eroded away. 5. Water seems to be present near the South Pole. 6. In general there seems to be an increasing demand for heavy launchers, and consequent pressure to increase the capability. 7. Thus in effect, all sense of time will seem to vanish for beings that reach the speed of light. 9. Read and translate Text 1C. Discuss the pyrotechnic igniters and the electrical spark igniters. Make a brief summary in English. Useful phrases: The text describes (considers) … . First we need to identify/ clarify/ pinpoint the problem. I’d like to stress/ highlight/ emphasize the following points … . In addition/ moreover/ furthermore, there are other interesting facts we should take look at. That covers just about everything I wanted to say about … . In conclusion I’d like to … . Text 1C The combustion chamber and nozzle. Ignition Part 2 Secure and positive ignition of the engine is essential in respect of both safety and controllability. The majority of engines are used only once during a mission, but the ability to restart is vital to manned missions, and contributes greatly to the flexibility of modern launch vehicles. A typical requirement is to restart the upper-stage engine after an orbital or sub-orbital coast phase, which enables the correct perigee of a transfer orbit to be selected, for example, irrespective of the launch site. The restart capability is therefore becoming a more common requirement. For single-use engines, including all solid propellant engines, starting is usually accomplished by means of a pyrotechnic device. The device is set off by means of an electric current, which heats a wire set in the pyrotechnic material. The material ignites, and a shower of sparks and hot gas from the chemical reaction ignites the gaseous or solid propellant mixture. Pyrotechnic igniters are safe and reliable. They have redundant electrical heaters and connections, and similar devices have a long history, as single-use actuators, for many applications in space. For this reason, they are often the preferred method of starting rockets. They are clearly one-shot devices, and cannot be used for restarting a rocket engine.
An electrical spark igniter, analogous to a sparking plug is generally used to ignite LH2/LO2 engines, which in principle provides the possibility of a restart. However, there is a difficulty in that the electric spark releases less energy than a pyrotechnic device, and there is also the possibility of fouling during the first period of operation of the engine, which may then put the restart at risk. Much design effort has been put into reusable igniters, and this will continue as restart capability becomes more desirable. For a single use, the Space Shuttle main engine has electric ignition for both the main combustion chamber and for the turbo-pump gas generators. In this case the spark is continuous for the period during which the igniter is switched on, and the system is contained in a small tube which forms part of the injector. The gaseous hydrogen and oxygen in the tube ignite first, and then the flame spreads to the rest of the chamber. By confining the initial gas volume to that in the tube, the risk of the flame being quenched by a large volume of cool gas is reduced. There is sufficient heat in the flame, once established in the tube, to prevent quenching. For a secure restart capability on manned missions, hypergolic propellants must be used. These have the property that they ignite on mixing, and so starting the engine is simply a matter of starting the flow of propellants into the combustion chamber. This process is used for all manned flight critical engines. It was used for the Apollo lunar transfer vehicle, and is used for the de-orbiting of the Space Shuttle. The most common combination of propellants is nitrogen tetroxide and UDMH. As mentioned before, these are liquid at room temperature and can be stored safely on board for a long time, with no special precautions. The disadvantage of these propellants is their rather low specific impulse, which is a little more than half of that achievable with liquid hydrogen and liquid oxygen. Safe and secure restartable engines using more powerful propellants would be a major advance, but these are yet to be produced. Restartable engines are preferred for upper stages, particularly for injecting spacecraft into elliptical transfer orbits. The use of this facility means that the argument of perigee can be selected correctly, independent of the launch site and time of launch. The higher exhaust velocity of cryogenic propellants combined with such a facility would convey a much greater advantage. The starting sequence for cryogenic engines is complicated, and will be dealt with after the propellant supply and distribution have been considered. Before this, the steering of rocket vehicles using thrust vector control will be discussed.