Basic Gas Turbine - A Couple of Q's
Hi all,
I am sitting BGT tomorrow and have a couple of questions that have popped up with contradicting answers:
How is exhaust noise reduced in gas turbines?
Am I right in thinking that ideally you want to reduce the airflow velocity; therefore it will have less shear between stationary (atmospheric) air and the exhaust jetstream; therefore a divergent duct is favoured (in a diverging duct velocity will decrease, temp and pressure increase). Is this correct?
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Why do Pressure and Temperature increase in a compressor?
a) Potential and Kinetic Energy increase
b) Volume Increases
c) Total internal energy decreases
d) Compressor is a convergent duct
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3) Which of these affects the efficiency of a turboprop in a negative way compared to a turbojet?
a) TAS
b) IAS
c) Density
d) Pressure
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What does the EEC do?
a) Fine tune fuel to nozzles
b) Automatically prevent engine from exceeding its parameters
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What factor taken alone will increase thrust?
a) Increased Pressure
b) Increase Temperature
c) Increase Density
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What two (2) factors determine/affect a Turbojets propulsive efficiency
a) Pressure and RPM
b) Density and Speed
c) Temperature and Speed
d) Temperature and RPM
Any help would be sincerely appreciated!