IV. Zur Ethik.

Дата добавления: 2015-10-19; просмотров: 554

Before You Begin

I. a)This is a cas-turbine engine. Try to identify its parts.

b) Read the text and check if your predictions were correct.

Reading

Gas Turbine Engine Components

The turbine engine consists of a rotary air compressor with an air intake, one or more combustion chambers, a turbine and an exhaust outlet.

There are two basic types of rotary air compressors: a centrifugal flow compressor and an axial flow one.

The centrifugal flow compressor is a single or two-stage unit which has an impeller to accelerate the air and a diffuser to produce the required pressure rise. The axial flow compressor is a multy-stage unite with alternate rows of rotating and stationary blades to accelerate and diffuse the air until the required pressure rise is obtained.

The combustion chamber has the difficult task that is to expand the air passing through the engine by burning fuel in the air stream. Although all combustion chambers work on the same principles, they may be installed in the engine in some different ways. The multiple combustion chamber layout is often used with engines having centrifugal compressors. Annular combustion chambers are used with engines having axial compressors.

The turbine provides the power to drive the compressor and accessories. It extracts energy from the hot gases released from the combustion system and expands them to a lower pressure and temperature. The turbine may consist of several stages, each using one row of stationary quide-vanes and row of moving blades.

The exhaust system passes the turbine discharge gases to atmosphere at a velocity, and in the required direction, to provide the resultant thrust.

Post-Reading

I. a) Find the Russian equivalents for the following English words and word combinations.

b) Make up sentences using these words.

II. Present the information from the text in the form of a table, marking the parts of the gas turbine engine and thier functions.

III. Fill in the gaps using the words from the box.

1.Annular combustion chambers are used with engines having _____ compressors.

2. The turbine extracts _____ from hot gases released from the _____ system and expands them to a lower _____ and temperature.

3. The centrifugal-flow compressor has an _____ to accrlerate the _____.

4. The task of the combustion chamber is to _____ the ir passing through the _____ by butning _____ in the air _____.

5. The turbine may consist of several _____, each using one _____ of stationary quide _____ and one row of _____ blades.

IV. Match the words with thier definitions.

V.a) Read the text. Substitute the underlined words with the words from the box below.

The gas turbine engine takes air from the atmosphere and, after compressing and heating, it uses some of its energy to drive the turbine. The mechanical arrangement of the gas turbine engine is simple. It consists of two main rotating parts, a compressor, a tubine and a combustion chamber. The turbojet engine is most suitable for high forward speeds. At aircraft speeds below 450 miles per hour the jet engine is less efficient than a propeller-type engine.

VI. a) Answer the questions according to the text.

1.What components does a gas turbine engine consist of?

2. How many basic types of rotary air compressor do you know?

3. What is the function of the diffuser?

4. What types of blades are there in the axial flow compressor?

5. Where is the fuel burnt?

b) Make up 3 more questions to the text.

Grammar

MAY

Модальный глагол may выражает разрешение или возможность совершить действие. На русский язык обычно переводится словами могу, можно. В Past Simple он имеет форму might. Формы будущего неопределенного времени не имеет:

Engineers having taken an active part in this progect may take their seats in the first raw.

Глагол may употребляется также для выражения предположения (с оттенком сомнения):

Не may not know about it.

Он может и не знать об этом. (Возможно, он не знает об этом.)

SHOULD

В качестве модального глагола употребляется также глагол should.

Глагол should выражает совет, субъективную необходимость совершения действия. На русский язык обычно переводится словами должен, следует. Имеет только одну форму should:

The instructions should be written in clear language.

Инструкции нужно писать (должны писать) ясным языком.

NEED

Модальный глагол need выражает необходимость совершения действия. На русский язык обычно переводится словами нужно, надо.

Он имеет только форму настоящего неопределенного времени need, т. е. форм прошедшего и будущего неопределенного времени не имеет:

We need have this device no more.

Нам больше не нужно это оборудование.

В отличие от других модальных глаголов вопросительная и отрицательная формы модального глагола need могут образовываться также и при помощи вспомогательного глагола to do в соответствующей форме, причем смысловой глагол в этом случае употребляется с частицей to:

Need we make this report?

Do we need to answer this letter?

Нам нужно сделать этот доклад?

You need not make this report.

You do not need to make this report.

На это письмо вам не нужно отвечать.

Exersices

I. Translate from Russian into English paying attention to modal verbs.

1. While designing an engine designers should take into consideration a lot of requirements.

2. This engine needs to be examined.

3. The engineers of this department may have had on the job training.

4. May I have a look at this circuit?

5. This aircraft needs no refueling.

II. Translate the text, find out all forms of modal verbs.

Mechanically, gas turbines can be considerably less complex than internal combustion piston engines. Simple turbines might have one moving part: the shaft/compressor/turbine/alternative-rotor assembly (see image above), not counting the fuel system.

More sophisticated turbines (such as those found in modern jet engines) may have multiple shafts (spools), hundreds of turbine blades, movable stator blades, and a vast system of complex piping, combustors and heat exchangers.

As a general rule, the smaller the engine the higher the rotation rate of the shaft(s) needs to be to maintain top speed. Turbine blade top speed determines the maximum pressure that can be gained,this produces the maximum power possible independent of the size of the engine. Jet engines operate around 10,000 rpm and micro turbines around 100,000 rpm.

III. Translate from Russian into English.

1. Этот двигатель возможно будет установлен на новый самолёт.

2. Следует рассмотреть предложения этой конструкторской группы.

3. Нужно провести тщательный осмотр компрессора в этой силовой установке.

4. Следует проверить показатели работы этой установки.

5. Возможно, отчёт будет завершён в срок.

Writing

Write a short description of the gas turbine engine using ideas from the text. Use the following decriptions:

- The engine consists of …

- The main parts are …

- The principle of operation is …

- The function of this part is …

- The geometry of this device is …