MODULE 15, GAS TURBINE ENGINE
1- On an axial flow, dual compressor forward fan engine, the fan turns the same speed as the :
a) High pressure compressor.
b) Low pressure turbine.
b) Forward turbine wheel .
2- A by-pass engine LP compressor :
a) Supplies less air than is required for combustion.
b) Supplies more air than is required for combustion.
c) Supplies only the required quantity of combustion .
3- A turbo jet engine gives:
a) Small acceleration to a large mass of air.
b) Large acceleration to a small mass of air.
c) Large acceleration to a large weight of air.
4- A jet engine derives its thrust by:
a) Drawing air into the compressor.
b) Impingement of the propelling gases on the outside air .
c) Reaction of the propelling gases.
5- In a reverse flow system the last stage of an axial flow compressor is often centrifugal,
this is to:
a) Provide initial turning of the airflow .
b) Prevent compressor surge.
c) Increase the temperature rise.
6- In a free turbine:
a) There is a clutch between compressor and power output shaft .
b) There is no mechanical connection with the compressor .
c) There is a direct drive with a free-wheel unit .
7- If an electrical de-icing system is operating, thrust will :
c) Remain constant.
8- A method of comparing engine efficiencies is by comparing:
a) Thrust to weight ratio.
b) Fuel consumption .
c) Specific fuel consumption.
9- "Ram effect" due to aircraft forward speed will cause the efficiency of the engine to:
a) Remain constant.
10-The efficiency of a gas turbine engine at altitude:
b) Increases .
c) remains constant .
11- Bernoulli's Theorem states that at any point in a flow of gas:
a) The static pressure is less than the dynamic pressure.
b) The static pressure and dynamic pressure are equal .
c) The total energy remains constant .
12- A bypass ratio of 5:1 indicates that the bypass flow is:
a) Equal to 1/5 of the hot stream .
b) Five times the cold stream.
c) Five times the hot stream.
13- In a turbo jet engine, combustion occurs at:
a) Constant velocity.
b) Constant volume.
c) Constant pressure.
14-The working fluid of a gas turbine engine is :
15- As subsonic air flows through a convergent nozzle the velocity:
a) increases .
c) remains constant
16- The stator vanes in an axial-flow compressor :
a) convert velocity energy into pressure energy.
b) Convert pressure energy onto velocity energy .
c) Direct air into the first stage rotor vanes at the proper angle.
17-What units in a gas turbine engine aid in stabilization of the compressor during low thrust
a) Bleed air valves .
b) Stator vanes.
c) Inlet guide vanes.
18- A nozzle is „choked‟ when the gas flow or air flow at the throat is :
- Summer '17
- sajad heidari
- compressor, RPM, gas turbine engine, Axial compressor