NIFE ENGINES exam verified questions and answers guaranteed pass

NIFE - ENGINES


1. EXPLAIN - Bernoulli's equation, given static pressure, dynamic pressure,
and total pressure: The total energy of a fluid can be separated into potential
(static pressure, or just pressure) and kinetic (dynamic pressure, or just velocity)
energy.

Total pressure is the sum of these in frictionless, incompressible, airflow.

Total Pressure = Static pressure + Dynamic pressure
2. *DESCRIBE - The behavior of airflow through a nozzle: Regardless of
speed, a nozzle always increases velocity and decreases pressure
3. *DESCRIBE - The behavior of airflow through a diffuser: Regardless of
speed, a diffuser always decreases velocity and increases pressure
4. *DESCRIBE - The shape of a subsonic nozzle: Convergent
5. *DESCRIBE - The shape of a subsonic diffuser: Divergent
6. *DESCRIBE - The shape of a supersonic nozzle: Divergent
7. *DESCRIBE - The shape of a supersonic diffuser: Convergent
8. IDENTIFY - the three main sections of a gas generator: Compressor,
combustion chamber (burner), and the turbine
9. DESCRIBE - the Brayton Cycle: An operating cycle that consists of four
events occurring simultaneously: intake, compression, combustion, and
exhaust. Used in gas turbines.

10. DESCRIBE - The Otto Cycle: Operating cycle where intake, compression,
combustion, and exhaust occur sequentially and usually with a piston.Used in
reciprocating engines.

11. DESCRIBE - the basic components and operation of a gas generator:
1.) Suck - Intake: Air collected
2.) Squeeze - Compressor: Air compacted
3.) Bang - Burner: Air combusted
4.) Blow - Turbine/Exhaust: Turbine turned and thrust generated
12. DESCRIBE - How pressure, temperature, and velocity changes through
each section of the gas turbine.: - Intake: Velocity down, Temp up, Pressure up
- Compressor: Velocity slightly up, Temp up, Pressure up
- Diffuser: Velocity down, Temp constant, Pressure up



,- Combustion: Velocity up, Temp up, Pressure down
- Turbine: Velocity up, Temp down, Pressure down
- Exhaust: Velocity up, Temp down, Pressure down
13. *PRACTICE - What happens to velocity though the intake?: Decreases
14 *PRACTICE - What happens to velocity though the compressor/diffuser?:
Decreases
15. *PRACTICE - What happens to velocity though the burner?: Increases
16. *PRACTICE - What happens to velocity though the Turbine/Exhaust?:
Increases
17. *PRACTICE - What happens to temperature though the intake?: Increases
18. *PRACTICE - What happens to temperature though the
compressor/diffuser?: Increases
19. *PRACTICE - What happens to temperature though the burner?:
Increases
20. *PRACTICE - What happens to temperature though the
Turbine/Exhaust?: Decreases
21. *PRACTICE - What happens to pressure though the intake?: Increases
22. *PRACTICE - What happens to pressure though the
Compressor/Diffuser?: Increases
23. *PRACTICE - What happens to pressure though the burner?: Decreases
24. *PRACTICE - What happens to pressure though the turbine/exhaust?:
Decreases
25. DESCRIBE - Gross and Net thrust: - Gross thrust: Measurement of thrust
due solely from the velocity of the exhaust gasses - Net thrust: Gross thrust
corrected for inlet airflow.

Net Thrust = Mass * ((Outlet velocity - Inlet Velocity )/ Time)
26. DESCRIBE - how atmospheric temperature effects thrust: As temperature
decreases, air density increases, thus mass increases, thus thrust increases.
Inverse relationship.
27. *PRACTICE - As atmosphere temperature increases, thrust ______:
decreases
28. *PRACTICE - As atmosphere temperature decreases, thrust ______:
increases
29. DESCRIBE - How altitude effects thrust: As altitude decreases, pressure
increases, thus mass increases, thus thrust increases. Inverse relationship.




, Temperature decreases with altitude, but not enough to effect thrust here.
30. *PRACTICE - As altitude increases, thrust ______: decreases
31. *PRACTICE - As altitude decreases, thrust ______: increases
32. DESCRIBE - How atmospheric pressure effects thrust: As pressure
increases, mass increases, thus thrust increases. Direct relationship.
33. *PRACTICE - As atmosphere pressure decreases, thrust ______:
decreases
34. *PRACTICE - As atmosphere pressure increases, thrust ______:
Increases

35 DESCRIBE - the effect of engine RPM on thrust: As engine RPM increases,
more air is thrust into the engine, increasing thrust.

At low RPM, a small adjustment to throttle will change thrust only a small amount.
At high RPM, a small adjustment to throttle will change thrust a lot.
36. DESCRIBE - the effect of airspeed on thrust, theoretically: As airspeed
increases, inlet airspeed approaches that of exhaust airspeed, reducing thrust.
37. DESCRIBE - the effect of the ram effect on thrust: As velocity increases,
more air is thrust into the engine, increasing thrust.
38. IDENTIFY - the cockpit instruments that measure thrust.: Engine
pressure ratio (EPR), Torquemeter, Tachometer
39. *DESCRIBE - the Engine Pressure Ratio (EPR) instrument: Shows the
ratio between the inlet and outlet airflow pressures.
40. *DESCRIBE - the torquemeter instrument: Shows the shaft horsepower
that is available to the propeller in rotor aircraft.
41. *DESCRIBE - the tachometer instrument: Shows the RPM of the engine
42. DESCRIBE - Inlet ducts within a gas turbine engine: Designed to provide
high pressure, turbulence-free, air to the engine. Always acts like a diffuser, never
a nozzle (Velocity decrease with a pressure increase)
43. DESCRIBE - Compressors within a gas turbine engine: Designed to
supply enough air to satisfy the requirements of the combustion section. Increases
pressure.
44. *LIST - The three types of compressors within a gas turbine engine:
Centrifugal, axial, axial-centrifugal
45. *DESCRIBE - Centrifugal flow compressors and their pros/cons: Inlet air
is directed into an impellor, where it is accelerated into a diffuser then around a