Engine Performance 🥇

Question 1

What is power

Answer 1

The rate of work

Question 2

What is gross thrust

Answer 2

Total thrust without drag of incoming air. Measured stationary at sea level under ISA conditions

Question 3

What is net thrust

Answer 3

Gross thrust - ram drag
Measured when moving

Question 4

What is torque

Answer 4

The amount of work that can be produced in a turning force

Question 5

What is 1hp mean

Answer 5

The power to lift 33,0000lbs exactly 1ft in 1min

Question 6

How many watts is 1hp

Answer 6

746

Question 7

Shaft horsepower SHP measures output in what type of turbines

Answer 7

Turboprop and turboshaft

Question 8

What is ESHP

Answer 8

Equivalent shaft horsepower,
It’s the small amount of thrust produced by turboprop/shafts directing hot gases rearward + SHP

Question 9

What is THP

Answer 9

Thrust horsepower
It is thrust delivered by the propeller
It is SHP - propeller loss

Question 10

SFC equation

Answer 10

SFC = Fuel flow / thrust

Question 11

What engines are afterburners used in and where are they installed

Answer 11

Low bypass engines and installed after the last stage of the turbine and before the exhaust nozzle

Question 12

Components of afterburners

Answer 12

Fuel manifold (injectors)
Flame holder
Ignition system
Exhaust nozzle

Question 13

What is the purpose of a water methanol mix

Answer 13

Increases density and lowers temperature of air entering the engine.
The water causes this and the methanol just acts as an antifreeze agent

Question 14

A geared turbofan allows higher bypass ratios meaning less fuel consumption and noise. This is because of

Answer 14

A planetary reduction gearbox between the fan and low pressure shaft allowing less stages of low pressure compressor and turbines to be used while producing the same amount of thrust