GAS TURBINE PERFOMANCE AND THRUST AUGMENTATION – Air

#1. When after burning the jet pipe will:

Close to allow for the decreased volume of gas.

Open to allow for the increased volume of gas.

Remain the same

Remain the same until the temperature reaches 1700C then open.

#2. When does the variable nozzle open?

When the exhaust temperature reaches 1700C

Automatic when after burning selected.

Automatic on take off.

Automatic when approaching Mach 1.

#3. When leaving the turbine the gas stream:

Increases velocity immediately to maximise thrust.

Is diffused to ensure the afterburning flame is stabilised.

Goes through a convergent duct to ensure the after-burning flame is stabilised.

Goes through a divergent duct to maximise thrust.

#4. Which of the following statements are correct with regard to after-burning? 1.Fuel consumption increases 2.Fuel consumption decreases .3 Pressure thrust decreases ,4 thrust increases, 5 pressure thrust increases, 6 EGT increases ,7 EGT decreases ,8 Thrust decreases.

6,5,4,1

1,3,4,6

2,4,5,6

8,1,5,7

#5. On a turbojet aircraft which of the following statements would be correct with the introduction of water into the combustion chamber?

Power can be restored up to its flat rated 100% only, and is prevented from exceeding its limitations due to a pressure sensor at the high pressure outlet.

Power can be restored up to its flat rated 100% only, due to a pressure sensor at the combustion chamber outlet.

Power can be restored up to its flat rated 100% only, due to a pressure sensor in the exhaust.

Power can be augmented above100% due to the denser mixture impinging on the turbine, which consequently drives the compressor quicker.

#6. In a turboprop aircraft with water methanol injection in the combustion chamber, which of the following statements would be correct?

SHP can be re-established up to 100% only, when operating in warmer climates.

SHP can be increased beyond 100% by maintaining the RPM and increasing the blade angle.

SHP can be increased beyond 100% by increasing RPM and decreasing the blade angle.

SHP can be increased beyond 100% by maintaining RPM and decreasing the blade angle.

#7. Water Methanol is injected into an engine so that the combustion chamber inlet temperature is reduced and there is:

A substantial power decrease.

A substantial power increase with no increase in fuel flow.

A substantial power increase which is due solely to the combustion of methanol.

An increase in power output solely due to the increased fuel flow, since methanol does not burn.

#8. When methanol is added to a water injection system:

It is an important source of fuel.

It is an anti-freeze.

It is an important source of fuel and an anti-freeze.

The temperature of combustion remains the same.

#9. Water injection is used for take off:

To cool the combustion chambers.

To cool the turbine blades.

Only at high altitude airfields where the prevailing temperature is high.

At airfields with an ambient temperature above 30F

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