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A rocket is a jet- propulsion device, in which all the propellants are burned rapidly at great pressure and release a large amount of energy. The exhaust gas is guided rearward at great velocity and produces the reactive force of propulsion.
In the rocket power plant all the propellants, as well as oxygen, which form the propulsive jet are within the vehicle itself, while other engines get oxygen from the atmosphere. Thus the rocket engine can be used in a vacuum and is able to provide a possible means of propulsion for interplanetary vehicles.
Besides, it is suitable for high-flying, high-speed missiles and as a primary or an auxiliary power plant of an aircraft.
Rocket engines are divided into two categories: solid and liquid.
The liquid-propellant rocket power plants can be started and stopped at will by the remote operation of the propellant control valves. This cannot be done with solid-propellant systems, because when they have once started, the fuel in the combustion chamber must continue to burn until it is exhausted.
Therefore the liquid-propellant rocket engines are used mostly for long durations and the solid-propellant rocket power plants are intended for short flights.
Задание 8. Дайте английские эквиваленты:
высвобождать энергию; выхлопной газ; назад; ракетная силовая установка; межпланетные летательные аппараты; кроме того; основная силовая установка; твердотопливные системы; предназначены для коротких полетов; по желанию.
Задание 9. Согласитесь или опровергните утверждение. Начинайте предложения с фраз: I’m afraid that’s wrong; you are quite right/ you are not quite right; that’s not quite so; I think you are mistaken; as far as I know; I think so; according to the text.
Rocket engines get oxygen from the atmosphere.
Rocket engines are suitable for high-flying high-speed missiles.
Rocket engines are divided into three categories.
Solid-propellant rocket power plants can be started and stopped at will.
Liquid propellant rocket engines are used for short flights.
Задание 10. Не глядя в текст, дополните предложения.
An engine is a means …...
The exhaust gas is guided …...
The propellants release …...
Rocket engines are suitable …...
The propellants used in a rocket engine may be …...
Liquid-propellant power plants can be …...
Once started the solid fuel must …...
Задание 11. Расскажите по-английски тему “Rocket Engines”.
Задание 12. Письменно переведите текст:
Undoubtedly the simpliest form of jet-propulsion power units is the rocket engine, but the rate at which it consumes fuel has prevented its adoption as a power plant for continuous operation over periods even as long as one hour. The main reason for this is that, unlike other types of engine, the rocket does not take the oxygen required to burn the fuel from its surroundings, but carries its own supply. A hydrocarbon fuel, such as petrol, requires about 3.5 times its own weight of oxygen to burn it completely; hence the weight of fuel that a rocket-propelled aircraft using fuel of this type would have to carry would be at least 4.5 times that for the equivalent air-consuming engine.
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