Exam Review 1 Flashcards
Type of Duct: -Velocity of air decreases -Expands in Diameter -Static pressure increases -Temp of air increases
Divergent Duct
In turbine engine, what is a common term applied to a divergent duct?
Diffuser
Type of Duct:
Increase Velocity of air
Decrease diameter
Decrease static pressure
Temperature of air decreases
Convergent Duct
Which component on a turbine eng is typically a Convergent duct?
Exhaust Nozzle
‘The sum of the static and dynamic pressures will always be equal’
Bernoulli’s Principle
Define Bernoulli’s Principle:
The SUM of (total pressures added) of the DYNAMIC & STATIC PRESSURES will always be equal
Often referred to as CONSTANT PRESSURE CYCLE
In a Turbine eng 4 events to support combustion occur constantly & simultaneously:
They are: –> Intake –> Compression –> Ignition/Power –> Exhaust.
Brayton Cycle
When do these 4 cycles occur?
Separately
How many degrees of crankshaft rotation are needed for all 4 events (cycles) to occur?
720 degrees
When must ignition occur?
every 720 degrees at ignition cycle
When does ignition normally occur during
Turbine engine operation??
At engine start-up
Typically a Spool or Rotor is defined as a single rotating unit with a compressor and turbine attached at ____ _____ of a shaft.
opposite ends
In ‘2 spool’ engine what is N1?
Low pressure compressor———–Low pressure turbine
In ‘2 spool’ engine what is N2?
High pressure compressor————High pressure turbine
In ‘3 spool’ engine what is N1?
Low pressure compressor——-Low pressure
In ‘3 spool’ engine what is N2?
Intermediate pressure rotor—–intermediate pressure turbine
In ‘3 spool’ engine what is N3?
High pressure compressor———High pressure turbine
It measures engine thrust output by comparing the pressure at the front to the pressure back of the engine.
outlet pressure/inlet pressure
EPR
List 5 primary areas within a turbine engine, front to back:
see picture:
IT IS A CONFIGURATION WHERE A PROPELLOR IS DRIVEN BY A TURBINE ENGINE.
The prop is typically driven thru a reduction gear system.
Turboprop engine
- It increases the static pressure from the inlet duct and directs it to the combustion chamber (thru diffuser) at the correct pressure (potential energy), velocity and temp
- The Rotor and Stator vanes create divergent ducts
- 1 complete COMP Stage is: A ROTOR followed by a STATOR.
AXIAL COMPRESSOR STAGE
Type of Duct:
Increase Velocity of air
Decrease Diameter
Decrease Static Pressure
Temperature of air decreases
Divergent Duct
- The purpose of the TURBINE section is to convert the kinetic (velocity) and heat energy of the combustion gases into mechanical energy to rotate the Turbine to drive the fan/propeller/compressors/accessories.
- The Turbine section is located downstream of the combustion section.
- 1 complete TURBINE Stage is defined as: A STATOR followed by a ROTOR.
axial turbine stage
Uses of Bleed air:
Cabin pressure
Starting
Anti-icing Systems
