Exam 3

Question 1

T/F The Ram Jet engine is the simplest of the jet engines in that it contains no moving parts.

Answer 1

True

Question 2

What are the four most common types of Jet Propulsions?

Answer 2

Turbinejet, Rocket Jet, Ram Jet, Pulse Jet

Question 3

Turbine Jet

Answer 3

A type of gas turbine engine which produces thrust through the hot gases exiting the exhaust section of the engine

Question 4

Rocket Jet

Answer 4

The simplest form of rocket made of metal, or even paper, filled with gunpowder or some other sort of rapid burning mixture of chemicals that rapidly expand when burned. The reaction to the escaping gases pushing out of the back creates thrust

Question 5

Ram Jet

Answer 5

Simplest form of jet engine. Must be assisted to 250 mph before started. Used as afterburners

Question 6

Pulse Jet

Answer 6

Operates by a step by step cycle there is a grill of shutters that opens to let air into the combustion chamber, then the hot exhaust gases force close the shutters which moves the gases down the tail pipe to the exhaust then springs force the shutters back open to bring in more air.

Question 7

Aircraft gas-turbines can generally be classified into what four types?

Answer 7

Turbo Jet and turbofan (thrust producing) turboprop and turboshaft (torque producing engines)

Question 8

T/F A high-bypass engine does not bypass as much air around the core as a low-bypass engine.

Answer 8

False

Question 9

The advantages of turbofans are _______, _______ and _________

Answer 9

Greater fuel efficiency , reduced noise, turbojet speeds, turboprop short-field take-off capability

Question 10

T/F Once combustion occurs, pressure is no longer the driving requirement. It is exit velocity.

Answer 10

True

Question 11

T/F In a jet engine, the compressor wheels are used to turn the turbine wheels.

Answer 11

False

Question 12

The amount of force or thrust produced depends on the _____ of the air moved through the engine and the extent to which this air can be ______ and ejected.

Answer 12

Amount of mass, accelerated

Question 13

A gas-turbine has four major sections:

Answer 13

Compressor, combustion, turbine nozzle

Question 14

The _____ engine accelerates a smaller volume of air than the turboprop engine but a larger volume than the turbojet engine.

Answer 14

Turbofan

Question 15

Turbofan engines may be _____-bypass or _______-bypass engines

Answer 15

High or low

Question 16

The fan diameter of a turbofan is much _______ than a propeller, but there are _______ blades and it has a greater _________.

Answer 16

Smaller, many, exit velocity

Question 17

A _______ engine is nothing more than a gas-turbine or turbojet engine with a reduction gear mounted in the front or forward end to drive a standard airplane propeller.

Answer 17

Turboprop

Question 18

The major disadvantages of the turboprop is that it does not deliver

Answer 18

More power/thrust from exhaust gases

Question 19

When it is necessary to increase velocity and decrease pressure of air in an engine, a ________ duct is used.

Answer 19

Convergent

Question 20

The inlet area can be controlled by a set of vanes known as the _______ vanes.

Answer 20

Inlet guide vanes

Question 21

There are two types of compressors with respect to airflow: the ______ type and the type.

Answer 21

Centrifugal and Axial

Question 22

The centrifugal compressor consists of three main parts: an ________, a _________, and a _________

Answer 22

Impeller diffuser, and compressor manifold

Question 23

What is the primary purpose of the compressor section in a gas turbine engine?

Answer 23

The primary purpose of the compressor section is to increase the pressure of the air that is entering the engine inlet and to discharge it to the combustor at the proper velocity, temperature, and pressure.

Question 24

Compressor stall occurs when the rotor blades’ AOA gets too high. This generally occurs under what conditions?

Answer 24

1. Turbulent of disrupted airflow to the engine inlet. 2. Excessively rich fuel flow caused by abrupt engine acceleration. 3. Contaminated or damaged compressors. 4. Damaged turbine components, causing loss of power to the compressor. 5. Engine operation above or below designed RPM

Question 25

The turbine _______ is a series of airfoil-shaped vanes arranged in a ring at the rear of the combustion section of a gas-turbine engine.

Answer 25

Nozzle diaphragm

Question 26

Turbines come in three types: the ______ turbine, the _______ turbine, and a combination of the two called a _____ _________ turbine

Answer 26

Impulse, reaction, impulse reaction

Question 27

During most operating conditions, the nozzle exit velocity reaches the speed of sound and th propelling nozzle is said to be _____ - that is, no further increase in velocity can be obtained unless the _______ is increased.

Answer 27

Choked, temperature

Question 28

The normal function of the exhaust nozzle, or cone, is to control the ______ and _______ of the exhaust gases.

Answer 28

Velocity, temperature

Question 29

The two most commonly used types of thrust reversers are the _______ system and the _________ system.

Answer 29

Aerodynamic or mechanical blockers

Question 30

The _______ section of a turbine engine is used to power engine and aircraft accessories such as fuel pumps.

Answer 30

Accessory drive (gearbox)