Thrust And Power - Ch 4

Question 1

Intake Momentum Drag

Answer 1

Reduces thrust

The faster you go, the less % acceleration you have

Question 2

Ram Effect

Answer 2

Compresses the air which increases the density which increases the thrust output

Question 3

Intake Momentum Drag and Ram Effect

Answer 3

Are equal and opposite and they cancel each other out.

Assuming constant exit thrust

Question 4

Low Bypass

Answer 4

We can assume that thrust remains constant

Question 5

TGT

Answer 5

Turbine Gas Temperature

Question 6

Thrust Settings

Answer 6

TOGA - T/O go around (5 mins)
Intermediate - CLB climb setting - (20 mins)
MCT/CON - Max Continuous Thrust (unrestricted)

Question 7

Propeller Thrust

Answer 7

The faster you are, the less thrust you have

Thrust also decreases as temp increases

Question 8

Work =

Answer 8

Force x Distance

Question 9

Power =

Answer 9

Force x distance/Time

= F x TAS

Question 10

PR AT

Answer 10

PR - RoClimb = power required / available curve

AT - Angle of Climb = Thrust and Drag curve

Question 11

Specific Fuel Consumption

Answer 11

Jet SFC: Fuel Flow / Unit of Thrust
Prop SFC: Fuel Flow / Unit of Power

SFC is proportional to Temp (more efficient: cold and dense)

Lower number is better

Question 12

Engines will also have an

Answer 12

Optimum RPM