Results
Q1. The effect on the temperature and pressure of the gases as they pass across the turbine is:
Correct answer is – both their temperature and pressure decrease.
Q2. Nozzle guide vanes are fitted before the turbine:
Correct answer is – to increase the velocity of the gas flow therefore reducing its pressure.
Q3. One reason for shrouding turbine blades is:
Correct answer is – to improve efficiency and reduce vibration.
Q4. The blades are usually attached to the turbine disc by a “Fir Tree” root. A tight fit is ensured during operation:
Correct answer is – by the action of centrifugal force.
Q5. The main contributory factors which cause creep in turbine blades are:
Correct answer is – high temperature and tensile loading.
Q6. A free power turbine:
Correct answer is – has no mechanical connection with the other turbine or compressor shafts.
Q7. The mixture of impulse and reaction blade shape in the average turbine blade is such that:
Correct answer is – the inner half is impulse and the outer half is reaction.
Q8. Blade creep is:
Correct answer is – permanent elongation due to heat and centrifugal force.
Q9. The net operating temperature of a gas turbine engine is limited by:
Correct answer is – the materials from which the nozzle guide vanes and the turbine blades are constructed.
Q10. The impulse-reaction blade is twisted along its length so that:
Correct answer is – the gas does equal work along the whole of its length.
