Types

Question 1

How many types of compressors are there?

Answer 1

3

Question 2

What are the 3 types of compressors?

Answer 2

Centrifugal flow, axial flow, centrifugal-axial flow

Question 3

Explain the centrifugal flow compressor.

Answer 3

Compression is achieved by accelerating air outward perpendicular to the longitudinal axis

Question 4

Explain the axial-flow compressor.

Answer 4

Compresses air by a series of rotating and stationary airfoils moving the air parallel to the longitudinal axis

Question 5

Explain the centrifugal-axial flow compressor.

Answer 5

Uses both, centrifugal and axial compressors to achieve the desired compression

Question 6

How many types of turbine engines are there for aircraft?

Answer 6

4 - turbojet, turboprop, turbofan, turboshaft

Question 7

How many sections does a turbojet consist of?

Answer 7

4 - compressor, combustion chamber, turbine section, and exhaust

Question 8

Explain the sequence of how the turbojet engine works.

Answer 8

Compressor section passes inlet air at a high rate of speed to the combustion chamber.

Combustion chamber contains fuel inlet and igniter for combustion.

Expanding air drives a turbine, which is connected by a shaft to the compressor, sustaining engine operation.

Accelerated exhaust gases from the engine provide the thrust.

Question 9

What’s a turboprop engine?

Answer 9

A turbine engine which drives a propeller through a reduction gear

Question 10

Explain the process of how a turboprop engine works.

Answer 10

Exhaust gases drive a power turbine connected by a shaft that drives the reduction gear assembly

Question 11

Why is reduction gearing necessary in a turboprop engine?

Answer 11

Optimum propeller performance is achieved at much slower speeds than the engines operating RPM.

Question 12

Why were turbofans developed?

Answer 12

Combines the best features of a turbojet and a turboprop.

Question 13

How are turbofan engines designed to develop more thrust?

Answer 13

By diverting a secondary airflow around the combustion chamber

Question 14

What is the benefit of bypass air?

Answer 14

Generates increased thrust, cools the engine, and aids in exhaust noise suppression.

Allows for turbojet-type cruise speed with lower fuel consumption.

Question 15

Generally, how many times is the inlet air divided in a turbofan engine?

Answer 15

At least 2 separate streams of air.

Question 16

What is the purpose of separating the inlet air in a turbofan engine?

Answer 16

One stream will pass through the engine core, while a second bypasses the engine core.

Question 17

What does “bypass ratio” refer to?

Answer 17

The ratio of the mass airflow that passes through the fan divided by the mass airflow that passes through the engine core.