GTS Mod 4 Moderate

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What is the purpose of combustor cooling air in a gas turbine engine?

To reduce gas temperature before entering the nozzle guide vanes

To aid combustion by increasing flame temperature

To increase heat transfer to the combustor outer casing

To minimize the heat transfer to the flame tube walls (correct)

Why is turbine cooling essential in a gas turbine engine?

To increase the thermal efficiency of the combustor

To reduce dilution air flow to the combustor

To cool the nacelle walls

To maintain operating tolerances within the turbine area (correct)

What is the function of dilution air in a gas turbine engine combustor?

To accelerate the combustion process

To increase heat transfer to the combustion chamber walls

To reduce gas temperature before entering the nozzle guide vanes (correct)

To cool the turbine discs

Why do turbine discs in a gas turbine engine need to be cooled?

To reduce thermal fatigue and expansion rates within the turbine area Signup and view all the answers

How does nacelle cooling air affect engine performance in a gas turbine engine?

By reducing heat transfer to the combustor outer casing Signup and view all the answers

What is the main function of the airflow in a nacelle cooling system?

To purge the nacelle of flammable vapours Signup and view all the answers

Why is icing protection rarely necessary for compressor rotor blades in a gas turbine engine?

As a result of the centrifugal action they experience Signup and view all the answers

In a gas turbine engine, which components may require anti-ice protection according to the text?

Inlet guide vanes and engine nose cone Signup and view all the answers

What is the purpose of a pneumatic anti-ice system in a gas turbine engine?

To prevent ice formation on engine surfaces Signup and view all the answers

How does keeping the airflow to a minimum benefit a nacelle cooling system?

Reduces engine drag Signup and view all the answers

What method is used to cool engine accessories during flight?

Ram air delivered through appropriately placed scoops in nacelle cowling Signup and view all the answers

How is induced cooling of engine accessories achieved during ground operation?

Compressor bleed air flowing through nozzles in the cooling air outlet duct Signup and view all the answers

How is airflow controlled in the engine accessory cooling system to ensure operation only during ground running?

By a valve Signup and view all the answers

Which method is NOT mentioned as a way to cool engine accessories in the text?

Cooling air generated by a blower fan driven by the accessory gearbox Signup and view all the answers

What is a method used to draw atmospheric air through the intake louvres for cooling?

The low pressure area created by air velocity through nozzles Signup and view all the answers

What is the purpose of pre-swirl nozzles in a gas turbine engine?

To reduce the temperature and pressure of the cooling air for blade cooling Signup and view all the answers

What plays a vital role in determining the life of turbine vanes and blades?

The operating temperature they are exposed to Signup and view all the answers

What was a significant improvement in the cooling methods of gas turbine engine components over time?

Implementing single pass internal cooling in the 1960s Signup and view all the answers

How does internal air cooling impact hardware life in a gas turbine engine?

It is vital for hardware life Signup and view all the answers

What is the purpose of creating a radial swirl in the cooling air for turbine blades and NGVs?

To assist efficient entry of air into the rotating cooling passages Signup and view all the answers

What is the purpose of turbine blade cooling in a gas turbine engine?

To prevent overheating and maintain the structural integrity of the turbine blades Signup and view all the answers

Which component controls turbine disc inter-stage cooling?

Turbine inter-stage seals Signup and view all the answers

How does hot gas intrusion affect turbine disc cooling?

Causes mainstream gas to flow into the disc cavities Signup and view all the answers

What is the function of multi-pass internal air film cooling in gas turbine engines?

To provide enhanced cooling for both vanes and blades Signup and view all the answers

Which type of cooling air helps prevent hot gas intrusion in turbine disc cavities?

Nacelle cooling air Signup and view all the answers

What is the main purpose of an engine internal cooling system?

To ensure parts of the engine do not overheat Signup and view all the answers

Which components of a gas turbine engine require cooling air according to the text?

Combustors and turbines Signup and view all the answers

What function does the combustor cooling serve in a gas turbine engine?

To absorb excess heat from the combustor Signup and view all the answers

In the context of engine internal cooling, what does LP stand for?

Low Pressure Signup and view all the answers

What percentage of air entering the combustor is allocated for combustor cooling?

20% Signup and view all the answers

What part of the gas turbine engine is responsible for controlling the amount of airflow according to the temperature of the tapped air?

Air regulators Signup and view all the answers

When the anti-ice shut-off valves are opened, where does the air flow next in the system?

On to the nose cone area Signup and view all the answers

What are the components typically found in a gas turbine engine anti-icing system?

Air regulators and anti-ice valves Signup and view all the answers

Which part of the gas turbine engine is used to tap hot air for anti-icing systems in some cases?

Diffuser Signup and view all the answers

What indicates a normal response to a gas turbine engine losing compressor air?

Rise in exhaust gas temperature Signup and view all the answers

Which component controls the amount of airflow in a gas turbine engine anti-icing system based on the temperature of the tapped air?

Air regulators Signup and view all the answers

Where is anti-icing air usually taken from in a gas turbine engine?

High pressure compressor Signup and view all the answers

What does a light in the cockpit indicate when the anti-ice switch is actuated?

Increase in exhaust gas temperature Signup and view all the answers

Which part of the gas turbine engine might register a discernible change when the anti-ice switch is actuated?

Engine pressure ratio and RPM indicators Signup and view all the answers

What part of the anti-ice system is responsible for allowing air to flow through to the nose cone area?

Air regulator Signup and view all the answers

How is the reset valve in the compressor bleed valve system activated?

By a reset cam connected to the bleed valve shaft Signup and view all the answers

Which component assists in applying low pressure (PT2) to the diaphragm in the compressor bleed valve system?

Spring force Signup and view all the answers