Turbofan

Question 1

What are the 5 different parts of a turbofan engine?

Answer 1

Fan, compressor, combustor, turbine, and mixer/nozzle

Question 2

What 2 parts of the engine does the air move through?

Answer 2

The engine core and around the outside of the core through a duct (bypass air)

Question 3

What’s the purpose of the compressor?

Answer 3

It compresses the air

Question 4

What type of compressor is in a turbofan?

Answer 4

Axial-flow

The air passes parallel to the shaft of the engine

Question 5

What happens to the blades as the air move further through the engine?

Answer 5

The blades becomes smaller, adding more energy and compression to the air

Question 6

What is in between each set of compressor blades?

Answer 6

Stators (AKA -Vanes)

Question 7

What’s the purpose of stators?

Answer 7

Increase the pressure of the air by converting rotational energy into static pressure

Also prepare the air for entering the next set of compressor blades by straightening the airflow out.

Question 8

What is a “stage”?

Answer 8

When a pair of rotating and stationary blades are combined

Question 9

What’s the combustor?

Answer 9

It’s where the fire happens, air is mixed with fuel and ignited.

Question 10

What are the different stages of the combustor?

Answer 10

Air flows in and hits a diffuser. This slows the air down to make it easier to ignite.

The dome and swirler add turbulence to the air so it can more easily mix with the fuel.

The fuel injector sprays the fuel into the air, creating the fuel/air mixture to be ignited.

The liner is where the combustion happens, it has several inlets which allow air to enter at multiple points in the combustion zone.

The igniter is similar to spark plugs, but once the igniter lights the fire, it is self sustaining and then it’s turned off.

Question 11

What is the turbine?

Answer 11

It comes after the combustor. It is a series of airfoil-shaped blades, similar to the compressor

Question 12

What happens when the hot, high speed air flows over the turbine blades?

Answer 12

Extracts energy from the air, spinning the turbine in a circle, and then turns the engine shaft which it’s connected to.

Question 13

What is the shaft that’s connected to the turbine also connected to?

Answer 13

The fan and also the compressor

Question 14

Why is it designed so that the fan and compressor are connected to the same shaft as the turbine?

Answer 14

The fan and compressor will continue sucking in more air that will be mixed with fuel and then burned.

Question 15

What’s the last section of the turbofan?

Answer 15

The nozzle

Question 16

What’s the purpose of the nozzle?

Answer 16

It’s essentially the exhaust duct of the engine, and it is where the high speed air shoots out the back of the engine.

Question 17

How does the air being pushed out of the back of the engine propel the aircraft forwards?

Answer 17

Newton’s 3rd Law.

Every action has a equal and opposite reaction.

Question 18

What is another design feature sometimes incorporated into the turbofan engine at the nozzle section?

Answer 18

There’s sometimes a mixer, which will mix bypass air with combusted air, making the engine quieter.