15.6 Turbine sections
Quiz
- Gas generator turbine is to absorb approximately ------ percent of the total pressure energy from the exhaust gases ?
- 40-50
- 60 to 70
- 80-90
- How many types of turbine are ?
- Three
- Two
- Four
- Most turbofan engines have ------?
- Single stage turbine
- Two spools
- Single spool
- Signs of -----on the turbine case may indicate the length of turbine blades is out of tolerance ?
- Creep
- Scoring
- Deformation
- Visible cracks may range in length from --------?
- One-sixteenth inch downward
- Five to ten inch
- One-sixteenth inch upward
- It increases with temperature and can result in observable dimensional changes to the blades ?
- Deformation
- Stress rupture cracks
- Creep
- It is caused by over-temperature and appear as waviness and/ or areas of varying airfoil thickness along the leading edge ?
- Deformation
- Stress rupture cracks
- Creep
- These usually appear as minute hairline cracks on or across the leading or trailing edge at a right angle to the edge length
- Deformation
- Creep
- Stress rupture cracks
- Which technique mostly used for Crack detection, when dealing with the turbine disk and blades ?
- Ultrasonic
- Eddy-current
- Visual
- The turbine shaft is usually fabricated from -------?
- Alloy steel
- Aluminium alloy
- Cast iron