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Expulsion (n) –выхлоп, выпуск, продувка

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UNIT 1

ENGINES.

VOCABULARY. TEXT A.

Engine (n) -- двигатель

We know different kinds of engines: steam engine, gasoline engine, diesel engine.

To propel (v) – двигать

Jet engines propel the rockets.

Vehicle (n) – средство передвижения (автомобиль, вагон, повозка и т.д. ) летательный аппарат

Motorcycles, airplanes, motor boats are all mechanically propelled vehicles.

Mobile (adj) – подвижной, мобильный

The new car was very light, comfortable and mobile.

Unit (n) – агрегат, секция, блок, узел, элемент

Wind tunnel fan is a very powerful unit.

To belong to (v) – принадлежать, относиться к ч-л

It doesn’t belong to the subgroup of internal combustion engines.

Prime-mover (n) – первичный двигатель

The steam engine was the prime- mover of all high-speed engines ever invented.

Internal-combustion engine (v) – двигатель внутреннего сгорания

Internal-combustion engines as all other engines turn heat energy into motion.

To divide (v) – делить, разделять

The designers divided the process into several phases.

Piston (n) – поршень 3

The piston compresses the fuel mixture.

Stroke (n) – ход поршня, удар

Combustion engines can be divided into several types according to the number of strokes.

To ignite (v) – зажигать, воспламенять

As an engine wasn’t in order, ignition didn’t occur.

To vaporize (v) – испарять, выпаривать

When heated water vaporizes into the atmosphere.

Admission (n) –доступ, впуск

The admission stroke didn’t take place because of the broken valve.

expulsion (n) –выхлоп, выпуск, продувка

The expulsion of used gases is the last phase in the cycle of internal-combustion engine.

VOCABULARY EXERCISES.

A. Complete the following sentences with the words from the list.

to ignite inward to complete

volatility advantage cycle

vehicles to expand to belong to

1. This unit doesn’t ----------- the steam engine.

2. Divide all ---------- according to the types of engines used.

3. The succession of operations is a ----------.

4. When heated all objects ----------.

5. Some chemical substances have such a feature as ----------.

6. ---------- something means to burn something.

7. To report about the results, scientists have to --------- the experiment.

B. Choose the correct answer to complete each statement.

1. As the ---------- moves, it compresses the gases.

a. cycle

b. piston

c. stroke

d. engine

2. The activities that take place in the engine cylinder can be ----------into four stages.

a. expanded

b. propelled

c. divided

d. completed

3. The word “stroke” ---------- to the piston movement.

a. referres

b. inward

c. mobile

d. vaporizes

4. This ---------- will not be used, as the engineers will make some design improvements.

a. stroke

b. cycle

c. admission

d. engine

5. The ---------- of time did not allow them to increase the flexibility of the design model.

a. advantage

b. prime-mover

c. lack

d. intermittent

6. A spark ---------- a mixture of gasoline vapor and air.

a. vaporizes

b. ignites

c. belongs to

d. divides

7. Steam engine was the first ---------- ever invented. 5

a. vehicle

b. prime-mover

c. internal-combustion engine

d. unit

C. Choose the synonymous pairs of words from your vocabulary list.

to move admission

to part to ignite

phase lack of

to finish to divide

shortage cycle

to burn to propel

intake to complete

D. Choose the antonyms to the words from your vocabulary list.

stable internal

to begin expulsion

outward advantage

disadvantage flexibility

excess lack

rigidity inward

external to complete

admission mobile

E. Translate the following “chains” of nouns.

road vehicles

farm tractors

motor boats

heat engines

combustion engines

piston stroke

engine cylinder

fuel economy

air charge

horse power

F. Read and translate the following words.

mechanically, motorcycles, mobile, industrial, type, cycle, to operate, cylinder, constantly, automotive, revolutions, gaseous, mixture, to compress, to expand, chief, to diffuse, uniformly, phase 6

G. Skim the text.

Begin your answer with the words: “ Этот текст о … “.

H. Read the text below and find the answers to the following questions.

1. What class and subdivision do the engines of practically all mechanically propelled vehicles belong to?

2. What is meant by the term “cycle”?

3. How may combustion engines be divided?

4. What can you say about the duration of the cycle?

5. What are the advantages of a two-stroke engine?

6. What can you say about six-cycle engine?

7. What are the main phases of the four-stroke engine?

TEXT A. INTERNAL-COMBUSTION ENGINES.

The engines of practically all mechanically propelled road vehicles, motorcycles, airplanes, farm tractors, motor boats, and mobile industrial units belong to the class of prime movers known as heat engines, and to the subdivision of “internal-combustion engines”.

Combustion engines may be divided into types according to the duration of the cycle on which they operate, in terms of piston strokes. By a cycle is meant the succession of operations in the engine cylinder which constantly repeats itself. The great majority of modern automotive engines operate on the four-stroke cycle, usually referred to as Otto cycle, which is completed in four strokes of the piston, or during two revolutions of the crankshaft. Engines are also being built to operate on a cycle which is completed in two piston strokes. In this cycle a combustible gaseous mixture is compressed in the cylinder during the outward stroke of the piston and burned and allowed to expand during the following inward stroke.

Two-stroke engines are used only in small units, and generally in applications where the operation is quite intermittent. Their chief advantage is low first cost; their disadvantages are low fuel economy and lack of flexibility.

A few engines have been built to operate on a six-stroke cycle, which has certain advantages where fuel is of low volatility is to be used. Four of the six strokes of this cycle are used for the same operations as in the four-stroke cycle; during the remaining two strokes the combustible mixture is retained in the cylinder without being ignited, to give a fuel a better chance to vaporize and to diffuse uniformly throughout the air charge.

Six-cycle engines have never reached a practical stage, and of all of the high-speed combustion engines in use today that operate on volatile fuels, more than 99 per cent of the total horse power undoubtedly work on the four-stroke cycle. 7

The four-stroke cycle comprises the following four phases or operations, which succeed one another in order in which they are given:

Admission of the charge to the cylinder.

Compression of the charge.

Combustion of the charge (which includes its ignition and expansion).

Expulsion of the products of combustion.

I. Choose the correct answer to complete each statement.

1. Combustion engines can be divided into types according to:

a. the number of cylinders;

b. the duration of the cycle;

c. the combustion inside the cylinder;

d. the expulsion of the combustion products.

2. The majority of modern engines operate on:

a. two-stroke cycle;

b. six-stroke cycle;

c. complete cycle;

d. four-stroke cycle.

3. The advantages of a two-stroke engine are:

a. low first cost;

b. low fuel economy;

c. lack of flexibility;

d. high productivity.

4. The fuel of low volatility is used in:

a. two-stroke engines;

b. six-stroke engines;

c. all engines;

d. four-stroke engines.

5. Six-cycle engines:

a. are widely used;

b. are not used at all;

c. have not reached the practical stage;

d. have very limited use.

6. The four-stroke cycle comprises four phases which:

a. proceed other phases;

b. succeed one another;

c. are simultaneous;

d. divide each other. 8

J. Match the definitions in column B with the terms in column A.

A B

CYCLE ----- is the class of prime-movers.

FOUR-STROKE CYCLE ----- is the succession of operations in the

engine cylinder.

PHASES ----- is the four strokes of the piston.

HEAT ENGINE ----- are operations which succeed one another.

K. Translate the following sentences paying attention to the Passive Voice.

1. The rotary motion is transmitted to the car wheels.

2. If the ignition system produces a spark, the mixture will be ignited.

3. Nearly all transport air-lines are equipped with air-cooled engines.

4. The mixture of gasoline vapor and air is ignited by a spark.

5. In recent years many non-metalic materials have been widely used in engineering.

6. Many kinds of heat engines are used in various types of machines.

7. Heat energy is converted into mechanical energy by a steam engine.

8. The basic moving parts of a simple four-cycle diesel engine are shown in a diagram.

9. The diesel is built heavier because it must withstand higher pressures.

L. There are sentences in Passive Voice in the second and the third paragraphs of the text. Find and translate them.

M. Answer the following questions.

1. What mechanically propelled road vehicles are mentioned in the text?

2. How are combustion engines divided?

3. What is the cycle?

4. What does the four-stroke cycle mean?

5. What does the two-stroke cycle mean?

6. What are the advantages and disadvantages of a two-stroke engine?

7. What are the remaining two strokes of a six-stroke cycle used for?

8. What can you say about the use of six-cycle engines?

9. What are the phases of the four-stroke cycle?

VOCABULARY MINIMUM TEXT B.

to notice замечать, обращать внимание

in many respects во многих отношениях

to run работать, приводить в движение

to produce производить, вырабатывать

to distinguish различать, распознавать

to require требовать

to heat (heat) нагревать, (тепло)

to draw втягивать

A. Read and translate the following “chains” of words.

gasoline engine suction stroke exhaust stroke

compression stroke power stroke ignition system

spark plug inlet valve compression ratio

fuel-air mixture liquid fuel fuel pump

injection nozzles

B. Skim the text. Answer the question: “What is this text about?”

TEXT B. HOW DIESEL ENGINES DIFFER FROM GASOLINE ENGINES.

If you know something about ordinary gasoline engine, such as those in automobiles, you will have noticed that diesel engines, in many respects, work in the same way.

Both types of engines run on liquid fuels. Gasoline engines have been made to run on kerosene, and so have diesel engines. Gasoline, kerosene, and diesel oil are all produced from natural petroleum (crude oil), and are distinguished mainly by their volatility, i.e. the ease with which they can be changed from a liquid to a vapor. Gasoline is quite volatile, i.e. it evaporates at a low temperature. Kerosene needs more heat to make it vaporize, while diesel oil requires still more heat.

Both types of engines are internal-combustion engines, i.e. they burn the fuel inside their cylinders. Most gasoline engines and many diesel engines work on the four-stroke cycle, i.e. the piston makes a suction (down), a compression stroke (up), a power stroke (down), and the exhaust stroke (up).

What, then, are the main differences between diesel engines and gasoline engines?

FIRST. A diesel engine has no ignition system – it has no spark plug. None of this is needed on a diesel engine because the fuel is ignited simply by the contact with very hot air which has been highly compressed in the cylinder. 10

SECOND. A diesel engine draws into the cylinder air alone, and it compresses this air on its compression stroke before any fuel enters the cylinder. On the other hand, a gasoline engine mixes air with fuel in the carburetor outside the cylinder before it enters the engine through the inlet valve during the suction stroke.

THIRD. Diesel engines use greater compression than gasoline engines. In a gasoline engine, the amount of compression or compression ratio is strictly limited because fuel, as well as air, is being compressed. If the combustible fuel-air mixture is compressed too much, it gets so hot, that it will ignite by itself. In other words the mixture will pre-ignite before the piston has completed its compression stroke, and will try to stop the piston.

The compression in a diesel engine is not limited by the possibility of pre-ignition because the diesel engine compresses air only.

FOURTH. Diesel engine use less volatile, heavier liquid fuels than gasoline engines. These heavier fuels are generally cheaper than gasoline. Gasoline engines must use this highly volatile fuels because only a fuel which evaporates at low temperature will form a uniform mixture with the rapid current of air flowing through the carburetor.

FIFTH. Diesel engines use fuel pumps and injection nozzles to inject the oil into the cylinder in the form of a fine spray. Gasoline engines, on the other hand, mix the fuel and air in a carburetor.

SIXTH. Diesel engines are heavier than gasoline engines of the same size

because they work against greater pressure, and consequently their parts must be

stronger. The greater strength is obtained by making the parts thicker and there-

fore heavier.

C. Find in the text the common features of gasoline and diesel engines.

D. Read the second paragraph of the text and answer the following questions.

1. What is the common feature of all kinds of fuels?

2. What kinds of fuel are mentioned in the paragraph?

3. How are the fuels distinguished?

4. What is volatility?

a. The change from a solid to a liquid.

b. ----- ----- ----- a liquid to a gas.

c. ---- ----- ------ a liquid to a vapor.

E.Find in the text all the features that differ diesel engines from gasoline engines.

DIESEL ENGINE GASOLINE ENGINE

1__________________________ 1._________________________

2._________________________ 2._________________________

3._________________________ 3__________________________

4._________________________ 4._________________________

5._________________________ 5._________________________

6._________________________ 6._________________________

F. Read the text again and explain the meaning of the term “pre-ignition”.

G. Study the terms in the diagram given on page 13 and find the meanings of them in the dictionary.

inlet valve ---

exhaust valve ---

rod ---

crankarm ---

crankshaft ---

bearing ---

fresh air ---

to descend ---

top ---

bottom ---

to deliver ---

oil spray ---

spent gases ---

to release ---

to force ---

H. Match the pictures with the definitions of the work of the basic moving parts of a four-cycle diesel engine given on page 13.

I. Read and translate the following text without a dictionary.

WHY WE CALL IT A “DIESEL” ENGINE?

You have learned earlier in this chapter that a diesel engine is one form of internal-combustion engine, the latter being an engine from which work is obtained by the combustion of fuel within the engine cylinders themselves.

A diesel engine is that type of engine which injects fuel oil in a finely divided state into a cylinder within which air has been compressed to a high pressure and temperature. The temperature of the air is high enough to ignite the particles of the injected fuel; no other means are used for ignition. Because of this method of ignition, diesel engines are sometimes called compression-ignition engines. This insets them apart from other internal-combustion engines called spark-ignition engines. These latter engines use gasoline or gas as fuel, and the mixture of fuel and air is ignited by an electric spark.

Why, than, do we call this compression-ignition engine by the name “diesel”? Simply because a man whose name was Rudolf Diesel originated in Germany and obtained patents in 1892 on a high-compression, self-ignition engine originally intended to burn powdered coal.

J. Put “plus”, if the statement is mentioned in the text, and “minus”, if not.

1._____ The temperature of a compressed air is very high, that is why it ignites the particles of the injected fuel.

2._____ Internal-combustion engines may use gas as a fuel.

3._____ Diesel engines are employed in a great many kinds of stationary power plants.

4._____ Diesel engine is a form of internal-combustion engines.

5._____ Many diesels look like gasoline engines.

6._____ Diesel engines are sometimes called spark-ignition engines.

7._____ High-compression, self-ignition engine intended to burn liquid fuel.

8._____ The diesel is built heavier because it must withstand higher pressures.

9._____ Compression ignition engine was named after Rudolf Diesel.

10._____ Internal-combustion engine was patented in 1892.

11._____ A spark plug is used in a diesel engine for ignition.

K. Read and translate the following texts in a written form using a dictionary.

TEXT A. DIESEL ENGINES.

The oil engine (diesel engine) is also a form of internal-combustion engine. It has the usual arrangement of cylinder, piston, connecting rod, crank, inlet and exhaust valves as we find in petrol engine. In place of carburetor and sparkling plug it has an injection pump and a fuel injection valve (injector). Unlike spark-ignition engines it uses the heat of compression to fire the fuel and is, therefore, called compression ignition engine.

It utilizes a fuel known as diesel oil, which is forced in the form of a fine spray through a suitable nozzle directly into the combustion space. No mixture of fuel and air is introduced into the cylinder, the compression-ignition (CI) engine draws in pure air only. This air is then compressed by the ascending piston to a high pressure. As a result of it the temperature of the air is raised considerably so that the fuel oil injected into the cylinder ignites rapidly. Thereafter the gaseous products expand providing the energy for the power stroke.

The high-output oil engines are nearly all of two-stroke type. The charge is filled into the cylinder by means of a blower which assists both the intake and exhaust processes. One cycle is completed within one revolution, i.e., in two strokes--- compression and expansion.

TEXT B. ENGINES.

The heat engine is a machine that converts heat energy to mechanical energy. The engines of motor-cars, motor-cycles, farm tractors, motor boats etc., are heat engines, which belong to the subgroup of internal-combustion engines. Combustion engines may be divided into several types according to the number of piston strokes. Most of modern automotive engines operate on four-stroke cycle. There are also engines which operate on two-stroke and six-stroke cycle.

A diesel engine is a machine which produces power by burning oil in a body of air which has been squeezed to a high pressure by a moving piston. Diesel engines are especially suitable where an independent source of power is required, as in ships, locomotives, mobile equipment of all sorts and isolated power plants.

Steam, gas and oil engines were known and used prior to the invention of the diesel engine. The steam engine converts the heat energy of steam to mechanical energy. A typical steam reciprocation engine consists of a cylinder fitted with a piston. A connecting rod and crankshaft change the piston to-and-fro motion into rotary motion. The steam pressure on the piston varies during the stroke, and it is the flywheel which maintains a constant output velocity.

TEXT C. ENGINE TYPES.

There are several types of such engines, depending upon cycle, location of parts, and other items. A partial designation of engine types could be as follows:

Types of fuel burned--- gasoline, kerosene, fuel oils, gases. 15

Methods of cooling---liquid or gas (air).

Arrangement of cylinders.

Valve location.

Cycle---four-stroke and two-stroke.

Type of valves.

Ignition---spark or compression.

Moving parts---piston or blade (turbine).

Compression---low, medium, high.

One of the most important engine designation is the cycle used. The usual outboard boat engine is of the two-stroke cycle. The usual tractor engine and all known automobile engines are of the four-stroke type.

The four-stroke cycle engine is sometimes improperly called the four-cycle engine. This is not a correct technical designation. It is simply an abbreviation of the longer descriptive term; it does not indicate that there are four piston strokes per cycle.

UNIT 2

AUTOMOBILES.

VOCABULARY. TEXT A.

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