Turbine Theory/Construction

Question 1

Four forces of flight:

Answer 1

Lift,
Gravity,
Thrust,
Drag.

Question 2

Newton’s 1st law:

Answer 2

An object at rest will remain at rest, and an object in motion will continue in motion in a straight line and will not change its velocity unless it is acted upon by an outside force.

Question 3

Newton’s 2nd law:

Answer 3

The amount an object will accelerate is inversely related to its mass and directly related to the amount of force acting on it.

Question 4

Newton’s 3rd law:

Answer 4

For every action there is an opposite and equal reaction.

Question 5

Bernoulli’s principle:

Answer 5

Any increase in the velocity of a moving fluid will result in a corresponding decrease in its pressure.

Question 6

A specially shaped restrictor in a tube designed to speed up the flow of fluid passing through it.

Answer 6

Venturi

Question 7

Turbine engines are rated in _____

Answer 7

Shaft horsepower.

Question 8

A duct that has a decreasing cross section in the direction of the flow.

Answer 8

Convergent duct.

Question 9

A duct that has an increased cross-sectional area in the direction of the flow.

Answer 9

Divergent duct.

Question 10

T/F

As pressure increases, temperatures decrease.

Answer 10

False

Temperature follows pressure.

Question 11

Subsonic air is ________. Compressible/Incompressible

Answer 11

Incompressible

Question 12

Supersonic air is _______. Compressible/Incompressible

Answer 12

Compressible.

Question 13

Rather than compressing in a venturi, subsonic air ______.

Answer 13

Speeds up.

Question 14

Three types of pressure commonly used in gas turbine engine technology:

Answer 14

Absolute pressure,
Gage pressure,
Differential pressure.

Question 15

Absolute pressure is referenced from ______.

Answer 15

Zero pressure.

Question 16

Gage pressure is referenced from ______.

Answer 16

Existing atmospheric pressure.

Question 17

Differential pressure is ______.

Answer 17

The difference between two pressures.

Question 18

The ICAO standard day atmospheric pressure is _____.

Answer 18

29.92 in. Hg
(Inches of mercury)

14.7 psi

Question 19

The ICAO standard day temperature is _______.

Answer 19

59 degrees F

15 degrees C

Question 20

4 types of jet propulsion engines:

Answer 20

1) Rocket (non-air breathing)
2) Pulse-jet
3) Ram-jet
4) Gas turbine

Question 21

4 types of gas turbine engines:

Answer 21

1) Turbojet
2) Turboprop
3) Turbofan
4) Turboshaft

Question 22

6 steps of air in a turbojet engine:

Answer 22

1) Air is drawn in.
2) Air is compressed.
3) Air is diffused.
4) Air combustion.
5) Air flows over turbines.
6) Air is exhausted.

Question 23

T/F

A turbofan engine is less efficient than a turbojet of comparable size.

Answer 23

False.

Question 24

T/F

As air velocity decreases, pressure increases.

Answer 24

True.

Question 25

A component of a gas turbine engine that decreases velocity and increases pressure of the air flowing through.

Answer 25

Diffuser.

Question 26

Only ______ of the air is used in the combustion of a gas turbine engine.

Answer 26

25%

Question 27

75% of the air taken into a gas turbine engine is used for _____ and ______.

Answer 27

Cooling.

Thrust.

Question 28

The constant pressure cycle of energy transformation used by gas turbine engines is called the ________.

Answer 28

Brayton cycle.

Question 29

Another name for a turbofan engine is ______.

Answer 29

Bypass engine.

Question 30

The ratio of the mass of air moved by the fan to the mass of air moved by the core engine is the ________.

Answer 30

Bypass ratio.

Question 31

A turbofan engine whose bypass ratio in less than 2:1 is a __________ engine.

Answer 31

Low bypass.

Question 32

A high bypass turbofan engine has a bypass ratio of ______.

Answer 32

4:1 or greater.

Question 33

2 types of turboprop engines:

Answer 33

1) Fixed shaft.

2) Free turbine.

Question 34

Air pressure is highest in a gas turbine engine at what stage?

Answer 34

As it exits the compressor and enters the burner section.

Question 35

Air in a gas turbine engine is at its highest temperature at what stage?

Answer 35

Between the combustors and the turbine.

Question 36

Air in a gas turbine engine is at its highest velocity at what stage?

Answer 36

As it exits the turbine to be exhausted.

Question 37

5 factors that affect thrust:

Answer 37

1) Airspeed.
2) Mass airflow.
3) Ram effect.
4) Water injection.
5) Afterburners.

Question 38

3 major limitations of reciprocating engines:

Answer 38

1) Must use heavy parts to withstand movement of pistons.
2) Large number of moving parts requiring frequent overhauls.
3) Can only produce thrust by driving a propeller.

Question 39

4 forces of motion:

Answer 39

1) Velocity
2) Acceleration
3) Momentum
4) Speed

Question 40

2 types of energy:

Answer 40

1) Kinetic

2) Potential