TurboFans

Question 1

A turbojet is the core component of what three turbine engines?

Answer 1

Turbofan
Turboprop
Turboshaft

Question 2

In addition to the turbojet engine core what gets added on to make it a turbofan?

Answer 2

A big fan stuck on the front. An additional turbine at the end powers this fan.

A turbofan engine is the most modern variation of the basic turbine engine (the turbojet)

Question 3

How does a turbofan work?

Answer 3

Incoming air passes through the fan. Some of it goes into the core but most of it goes out the edges as thrust.

The rest is the same as the basic turbojet.

Question 4

How much more efficient are turbofans vs turboprops?

Answer 4

30-40%

Question 5

What is engine Pressure Ratio (EPR)?

Answer 5

Its the ratio of the Turbine Outlet Pressure (out the back) to the Compressor Inlet Pressure (in the front)

A fancy way of saying how much thrust we’re producing.

Question 6

What is the Bypass Ratio?

Answer 6

The amount of air going around the core turbine from the turbofan