Piston Engine Power, Efficiency And Control

Question 1

For an engine with a constant speed propellor, what is used as an indication of power?

Answer 1

Manifold pressure and RPM together.

Question 2

What is the correlation between thermal efficiency and increased compression ratio?

Answer 2

Positive/increasing thermal efficiency = increased compression ratio.

Question 3

What is SFC and what does it indicate?

Answer 3

Specific fuel consumption, indicates fuel efficiency of the engine. The mass of fuel required to provide a given mount of power for a given time.

Question 4

Unit used for specific fuel consumption?

Answer 4

KG per kilowatt hour

Question 5

What is FADEC and what does it do?

Answer 5

Fall Authority Digital Engine Control. Computerised control of multiple engine variables, such as mixture, propellor pitch, throttle position, utilises normally one lever per engine as opposed to three. E.g DA42 thrust lever.