Module 2

Question 1

is essentially a heat engine using air as a working fluid to provide thrust.

Answer 1

Gas turbine engine

Question 2

To achieve this, the air passing through the engine has to be accelerated; this means that the (?) of the’ air is increased.

Answer 2

velocity or kinetic energy

Question 3

To obtain this increase, the (?) energy is first of all increased, followed by the addition of (?) energy, before final conversion back to (?) energy in the form of a high velocity jet efflux.

Answer 3

1. pressure
2. heat
3. kinetic

Question 4

gases flowing through the exhaust nozzle. Also known as jet blast and Jet engine exhaust.

Answer 4

JET EFFLUX

Question 5

For gas turbine engine, combustion occurs at a constant (?).

Answer 5

pressure

Question 6

In a piston engine combustion occurs at constant (?).

Answer 6

volume

Question 7

Both engines have induction, compression, combustion and exhaust. These processes occurs (?) on gas turbine engines.

Answer 7

continuously

Question 8

Both engines have induction, compression, combustion and exhaust. For piston engines they occur (?).

Answer 8

intermittently (at intervals)

Question 9

In piston engines, (?) is utilized for the production of power, the other strokes involve charging, compressing and exhausting of the working fluid.

Answer 9

only one stroke

Question 10

The turbine engine eliminates the (?), thus enabling more fuel to be burnt in a shorter time; hence it produces a greater power output for a given size of engine.

Answer 10

three “idle” strokes

Question 11

The turbine engine eliminates the three “idle” strokes, thus enabling more fuel to be burnt in a shorter time; hence it produces a greater (?) for a given size of engine.

Answer 11

power output

Question 12

Due to the continuous action of the turbine engine and the combustion chamber is not an enclosed space, the pressure of the air does not (?). But on piston engines, volume (?).

Answer 12

1. rise
2. increases (heating at a constant pressure)

Question 13

GTE
Under these conditions, there is (?) to be withstood.

Answer 13

no peak or fluctuating pressures

Question 14

With the piston engine, the peak pressure is of (?).

Answer 14

1,000 lb/in2

Question 15

Piston engine necessary to employ cylinders of (?) construction and to use (?) octane fuels.

Answer 15

1. heavy
2. high

Question 16

Gas turbine engines use (?) octane fuels and (?) fabricated combustion chambers.

Answer 16

1. low
2. light

Question 17

Because the turbo-jet engine is a heat engine, the (?) the temperature of combustion the (?) is the expansion of the gases.

Answer 17

1. higher
2. greater

Question 18

The (?) must not exceed a value that gives a turbine gas entry temperature suitable for the design and materials of the turbine assembly.

Answer 18

combustion temperature

Question 19

The use of (?) in the turbine assembly permits a higher gas temperature and a consequently higher thermal efficiency.

Answer 19

air-cooled blades

Question 20

During the working cycle of the turbine engine, the (?) receives and gives up (?), so changes in its pressure, volume and temperature occur.

Answer 20

1. airflow (working fluid)
2. heat

Question 21

These changes as they occur are closely related, for they follow a common principle that is embodied in a combination of the (?).

Answer 21

Laws of Boyle and Charles

Question 22

This means that the product of the pressure and the volume of the air at the various stages in the working cycle is proportional to the absolute (?) at those stages.

Answer 22

temperature of the air

Question 23

Whether energy is added by combustion or by compression, or is extracted by the turbine, the (?) is directly proportional to the work added or taken from the gas.

Answer 23

heat change

Question 24

Law that pressure of a given mass of an ideal gas is inversely proportional to its volume at a constant temperature.

Answer 24

BOYLE’S LAW

Question 25

Law that the volume of an ideal gas at constant pressure Is directly proportional to the absolute temperature. (Zero Kelvin corresponds to - 273.15 degrees Celsius).

Answer 25

CHARLES’ LAW

Question 26

The gas turbine engine is essentially a heat engine using air as a working fluid to provide thrust. To achieve this, the air passing through the engine has to be (1); this means that the velocity or kinetic energy of the air is increased. To obtain this increase, the (2)is first of all increased, followed by the addition of (3), before final conversion back to kinetic Energy in the form of a high velocity (4).

Answer 26

1. ACCELERATED 2. PRESSURE ENERGY 3. HEAT ENERGY 4. JET EFFLUX

Question 27

Combustion occurs at a constant pressure

Answer 27

GAS TURBINE ENGINE

Question 28

Combustion is continuous

Answer 28

GAS TURBINE ENGINE

Question 29

Combustion occurs at a constant volume.

Answer 29

RECIPROCATING ENGINE

Question 30

Combustion is intermittent

Answer 30

RECIPROCATING ENGINE

Question 31

eliminates the three 'idle' strokes, thus enabling more fuel to be burnt in a shorter time; hence it produces a greater power output for a given size of engine

Answer 31

GAS TURBINE ENGINE

Question 32

only one stroke is utilized in the production of power, the others being involved in the charging, compressing and exhausting of the working fluid.

Answer 32

RECIPROCATING ENGINE

Question 33

Due to the continuous action of the turbine engine and the fact that the combustion chamber is not an enclosed space, the pressure of the air does not rise, like that of the piston engine, during combustion but its volume does increase. This process is known as heating at constant pressure (?).

Answer 33

Charles Law

Question 34

Because the turbo-jet engine is a heat engine, the higher the temperature of combustion the greater is the (?) of the gases.

Answer 34

expansion

Question 35

The use of (?) in the turbine assembly permits a higher gas temperature and a consequently higher thermal efficiency.

Answer 35

air-cooled blades

Question 36

During the working cycle of the turbine engine, the airflow or 'working fluid' receives and gives up heat, so producing changes in its (1). These changes as they occur are closely related, for they follow a common principle that is embodied in a combination of the (2).

Answer 36

1. pressure, volume and temperature 2. laws of Boyle and Charles

Question 37

Briefly, this means that the product of the pressure and the volume of the air at the various stages in the working cycle is proportional to the absolute (?) of the air at those stages.

Answer 37

temperature

Question 38

There are three main conditions in the engine working cycle during which these changes occur.

Answer 38

compression combustion expansion

Question 39

During (?), when work is done to increase the pressure and decrease the volume of the air, there is a corresponding rise in the temperature.

Answer 39

compression

Question 40

During (?), when fuel is added to the air and burnt to increase the temperature, there is a corresponding increase in volume whilst the pressure remains almost constant.

Answer 40

combustion

Question 41

During (?), when work is taken from the gas stream by the turbine assembly, there is a decrease in temperature and pressure with a corresponding increase in volume.

Answer 41

expansion

Question 42

When the air is compressed or expanded at 100 percent efficiency, the process is said to be (?).

Answer 42

ADIABATIC

Question 43

(?) percent is good adiabatic efficiency for the compressor and turbine.

Answer 43

90 PERCENT

Question 44

during compression, a rise in the (?) of the air is required and not an increase in its velocity.

Answer 44

pressure

Question 45

After the air has been heated and its internal energy increased by combustion, an increase in the (?) of the gases is necessary to force the turbine to rotate.

Answer 45

velocity

Question 46

At the (?) a high exit velocity is required, for it is the change in the momentum of the air that provides the thrust on the aircraft.

Answer 46

propelling nozzle

Question 47

Local decelerations of (?) are also required, as for instance, in the combustion chambers to provide a low velocity zone for the flame to burn

Answer 47

airflow

Question 48

These various changes are effected by means of the size and shape of the (?) through which the air passes on its way through the engine.

Answer 48

ducts

Question 49

These shapes apply to the (?) where the airflow velocity is subsonic or sonic, i.e. at the local speed of sound

Answer 49

gas turbine engine

Question 50

The design of the (?) is of great importance, for upon their good design will depend the efficiency with which the energy changes are effected.

Answer 50

passages and nozzles

Question 51

Any interference with the smooth airflow creates a loss in efficiency and could result in component failure due to vibration caused by (?) or turbulence of the airflow.

Answer 51

EDDIES

Question 52

The path of the air through a gas turbine engine varies according to the (?) of the engine.

Answer 52

design

Question 53

The major difference of a turbo-propeller engine TO GTEs is the (?).

Answer 53

conversion of gas energy into mechanical power to drive the propeller

Question 54

Turboprop: The majority of the energy in the gas stream is absorbed by additional (?), which drive the propeller through internal shafts

Answer 54

turbine stages

Question 55

Turboprop: Only a small amount of (?) is available from the exhaust system.

Answer 55

'jet thrust'

Question 56

the (?) involves a division of the airflow.

Answer 56

by-pass principle

Question 57

Conventionally, all the air taken in is given an initial (?) compression and a percentage is then ducted to by-pass, the remainder being delivered to the combustion system in the usual manner.

Answer 57

low

Question 58

What is Newtons third Law of Motion?

Answer 58

LAW OF ACTION AND REACTION

Question 59

The term used for each set of stators and rotors

Answer 59

AXIAL FLOW

Question 60

This type of compressor incorporates an impeller

Answer 60

CENTRIFUGAL FLOW

Question 61

He patented the first Jet Engine

Answer 61

RENE LORIN

Question 62

Patented the first Gas Turbine Engine

Answer 62

FRANK WHITTLE

Question 63

What does "Athodyd" mean?

Answer 63

AERO THERMO DYNAMIC DUCT

Question 64

This type of Engine carries its own oxygen source

Answer 64

ROCKET ENGINE

Question 65

What will happen to the temperature of air if the pressure inside the engine is increased?

Answer 65

AIR TEMPERATURE INCREASES

Question 66

If temperature of air is increased, what is happening to the pressure?

Answer 66

AIR PRESSURE INCREASES

Question 67

The term used for changing air temperature to produce a propulsive force

Answer 67

JET PROPULSION

Question 68

Why are turbine engines more powerful than reciprocating engines?

Answer 68

TURBINE ENGINES ARE MORE POWERFUL THAN RECIPROCATING ENGINES BECAUSE THE COMBUSTION OF TURBINE ENGINES IS CONTINUOUSLY. IT CAN PROVIDE GREATER POWER OUTPUT. WHILE THE COMBUSTION OF RECIPROCATING ENGINES IS INTERMITTENTLY OR AT INTERVALS. IT CAN PROVIDE LOWER POWER OUTPUT THAN THE COMBUSTION OF TURBINE ENGINES THAT ARE GREATER.

Question 69

Why did it take 11 years for the whittle engine to achieve its first flight?

Answer 69

IT TAKE 11 YEARS FOR THE WHITTLE ENGINE TO ACHIEVE ITS FIRST FLIGHT BECAUSE BY THEIR TIME, THEY NOT YET DISCOVERED THE OTHER ELEMENTS OR METALS SUCH AS TITANIUM, ALUMINUM AND THEIR ALLOYS.

Question 70

What do we call the cycle in turbine engine?

Answer 70

Brayton Cycle