History of Gas Turbine Engines and Introduction to Jet Propulsion

Question 1

states that for every force acting on a body, there is an opposite and equal reaction

Answer 1

Isaac Newton’s Third Law of Motion

Question 2

It is the force which is generated in the opposite direction to that of a discharge of fluid under pressure, escaping through an opening.

Answer 2

jet propulsion

Question 3

operates on Sir Isaac Newton’s Third Law of Motion

Answer 3

jet propulsion

Question 4

It consisted of a sphere into which steam was introduced under pressure.

Answer 4

hero’s engine

Question 5

In a Hero’s Engine, the steam escaping through the nozzle mounted opposite one another on the surface of the sphere, created _____, which caused the sphere to rotate around its axis.

Answer 5

thrust

Question 6

One of the first attempts in developing jet powered aircraft resulted in the development of a hybrid design wherein the compressor output was mixed with fuel, the combination was burnt and jet thrust resulted.

Answer 6

Campini Camproni CC-2

Question 7

A year earlier than CC-2, the Germans had flown their version of a jet powered aircraft; the engine was designed by young German scientist Hans von Ohain.

Answer 7

Heinkel 178

Question 8

Sir Frank Whittle submitted patents for his jet engine in 1930 but it was not until 1939 that sufficient financial and technical backing was found to enable him to manufacture a flyable version of his engine. The firm of Rover had initially been contracted to produce the Whittle engine, but Rolls Royce eventually took over the development of the engine.

Answer 8

Gloster E28/39

Question 9

Rolls Royce reworked the Whittle engine to produce the ‘Derwent’ engine. Later versions of the engine, capable of 3,600 lb of thrust, were used to power the _________.

Answer 9

Gloster Meteor F8

Question 10

During a visit to the United States, the leader of the Rolls Royce design team found that the Americans were developing engines capable of producing up to 4,000 lb of thrust. On his return to Britain, he initiated a project which culminated in the _________, which at the time was the most powerful engine in the world, with 5,000 lb of thrust.

Answer 10

Nene engine

Question 11

propulsion devices

Answer 11

air breathing, rockets

Question 12

uses atmospheric air and some fuel as main propellant

Answer 12

air breathing

Question 13

examples of air breathing

Answer 13

• piston engines
• ramjet
• scramjet
• pulsejet
• gas turbine engines

Question 14

carries the entire propellant composed of liquid or solid fuel and the oxygen

Answer 14

rockets

Question 15

Basic Operation of Jet Propulsion Engines

Answer 15

1. Air enters through the air intake
2. Air is compressed by passage through the compressor
3. Air is mixed with fuel in the combustion chamber
4. Fuel is ignited; Pressure and Temperature raised
5. Some of the pressure is used to turn the turbine
6. Turbine shaft drives the compressor
7. Hot and high-pressure air is forced through the nozzle
8. The reaction force is the engine thrust

Question 16

The main function of any airplane propulsion system is to provide a force to overcome the aircraft drag, this force is called ________.

Answer 16

thrust

Question 17

Newton’s Second Law of Motion states that

Answer 17

force equals mass accelerated

Question 18

In a jet propulsion system, what is the mass and the force?

Answer 18

mass is air, force is thrust

Question 19

In a jet engine, the acceleration of air is __________ proportional to thrust.

Answer 19

directly

Question 20

two ways jet engine thrust can be increased

Answer 20

• increase the speed of exhaust gases
• increase the quantity of exhaust gases

Question 21

Increased engine thrust will make an aircraft fly ______ or with _______.

Answer 21

faster, more weight

Question 22

Types of Jet Engines

Answer 22

gas turbine engine, ramjet, pulse jet, scram jet, rocket engine

Question 23

It is by far the most practical form of jet engine in use today. It has become the standard on nearly all transport category, business, and military aircraft.

Answer 23

gas turbine engine

Question 24

works in the same manner as a reciprocating engine but all events happen simultaneously

Answer 24

gas turbine engine

Question 25

What is athodyd?

Answer 25

aero-thermodynamic-duct

Question 26

An athodyd which has no rotating parts and consists of a duct with a divergent entry and a convergent or convergent-divergent exit.

Answer 26

ramjet

Question 27

In a ramjet, with a forward motion imparted by an external source, air is forced in the ________ inlet, increasing its pressure, the total energy of air is further increased by combustion of fuel and the rapid expanding gases accelerate to the atmosphere through the outlet duct.

Answer 27

divergent

Question 28

can be run at static conditions unlike the ramjet and is constructed with a robust construction

Answer 28

pulse jet

Question 29

In a pulse jet, inlet duct has ________ inlet valves to the open position.

Answer 29

spring loaded

Question 30

In a ________, as air passes to the combustion chamber, it produces high pressures as to force the valves close. As the exhaust gases exits, this creates a low pressure which allows the valves to open and repeat the cycle.

Answer 30

pulse jet

Question 31

unstable as a powerplant due to high fuel consumption and cannot match performance of modern gas turbine engines

Answer 31

pulse jet

Question 32

It is a variant of a ramjet air breathing jet engine in which combustion takes place in supersonic airflow.

Answer 32

scram jet

Question 33

As in ramjets, a scramjet relies on high vehicle speed to compress the incoming air forcefully before combustion (hence ramjet), but whereas a ramjet decelerates the air to subsonic velocities before combustion, the airflow in a scramjet is supersonic throughout the entire engine. That allows the scramjet to _______________________.

Answer 33

operate efficiently at extremely high speeds

Question 34

A jet engine that does not use atmospheric air as a propulsive fluid stream (non-air breathing).

Answer 34

rocket engine

Question 35

uses propellants thus enabling outside atmospheric operations

Answer 35

rocket engine

Question 36

The ______ is the air delivered by the compressor.

Answer 36

mass

Question 37

_________ is the difference between the outlet velocity of the air to that of its inlet velocity due to the addition of the heat energy.

Answer 37

acceleration

Question 38

In gas turbine engines, combustion occurs at _______.

Answer 38

constant pressure

Question 39

________ is developed in the turbine of the engine.

Answer 39

power

Question 40

The processes occur in a __________ in a gas turbine engine.

Answer 40

continuous manner

Question 41

In the piston engine, only one stroke is utilized in producing power, the other three are effectively absorbing power. In the gas turbine engine, the three 'idle' strokes have been eliminated, thus allowing more time for the ________.

Answer 41

burning of fuel

Question 42

Theoretically, combustion int he gas turbine engine occurs at a constant pressure. This is achieved partly because of the continuous process of the _______, and also the fact that combustion chamber is not an ____________. This results in preventing fluctuations in pressure which is occurring in the piston engine.

Answer 42

Brayton cycle, enclosed space