Turbine Test 2
Card Set Information
Turbine Test 2
Turbine Test Turbines AAC Alabama Aviation Center Henderson
A set of notes to study for Turbine Test # 2.
Highest pressure point in a turbine engine?
What is 1 function of the nozzle diaphragm in a turbine?
- to raise velocity
- to direct airflow
What is a profile of a compressor blade?
A cut out to reduce tip thickness
In a dual spool compressor, the forward spool is also known as?
- LPC - low pressure compressor
PT7 stands for?
Total pressure station 7
When blending blades, how do you file them?
Parallel to the grain structure
What engine section mixes the fuel and air?
Combustion occurs at what pressure?
At high engine speeds, thrust will increase rapidly with?
Small changes in RPM
For a dual spool compressor at high altitudes, compressor speed will increase when?
What are the 3 ways to identify the diffuser?
-outlet of compressor
-inlet of combustor
what are the 2 functions of a stator?
-to raise pressure
-to direct airflow
What is the main function of the turbine?
to drive the compressor
In a dual spool engine, the first stage turbine drives which compressor?
What are the 2 basic elements of the compressor section?
stator and rotor
What are the 2 elements in a centrifugal compressor?
impeller and diffuser
If there are vanes on both sides of an impeller it is?
a dual entry
Some manufacturers identify turbine discharge pressure as?
What makes up the hot section?
combustion, trubine, exhaust
What makes up the cold section?
inlet, compressor, diffuser
What is needed to weld and straighten turbine blades?
Is welding and straightening turbine blades recommended?
No, it's better to replace them
What can you NOT mark on a turbine section with?
What is the advantage of axial flow compressors?
higher compression ratio for each stage added
What are 3 types of turbine blades?
Impulse, Reaction, & Combination (Impulse Reaction)
A propeller has what affect on air?
It has a small acceleration to a large mass of air
A turbine has what affect on air?
It has a high acceleration to a small mass of air
Axial flow compressors equal?
high peak efficiency
What is the purpose of the diffuser?
increase pressure and decrease velocity
Where do stress ruptures usually happen on a turbine blade?
leading and trailing edge (90 degrees to the grain)
Why are turbine blades more susceptible to damage than compressor blades?
because of the heat
What is the limiting factor of a turbine engine?
TIT (Turbine Inlet Temperature)
How do you reduce vibration and improve airflow in a turbine?
use shrouded blades to prevent tip losses
Which engine compressor offers the greatest advantage for starting and performance?
split spool axial flow
If you remove a blade for inspection, how must it be reinstalled?
in the same position it was removed from
What is one advantage of a centrifugal compressor?
high pressure rise per stage
What are the 2 types of centrifugal compressors?
single entry and dual entry
What is the name of the stationary blades on the compressor section?
What is the standard day pressure?
29.92" HG & 14.7 PSI
What is the standard day temperature?
59 degrees F
If you have a turbine blade that is overtemped, what kind of failure should be expected?
stress ruptures on blades
When are hot section inspections usually performed?
on a time or cycle basis
The purpose of the shroud on a turbine blade?
to reduce vibration