15.7 MCQ Flashcards
- The function of the exhaust cone assembly of a turbine engine is to.
Option A. swirl and collect the exhaust gases into a single exhaust jet.
Option B. collect the exhaust gases and act as a noise suppressor.
Option C. straighten and collect the exhaust gases into a solid exhaust jet.
Option C. straighten and collect the exhaust gases into a solid exhaust jet.
- A nozzle is ‘choked’ when the gas flow or air flow at the throat is.
Option A. sonic.
Option B. subsonic.
Option C. supersonic.
Option A. sonic.
- The struts on the exhaust cone.
Option A. straighten the gas flow only.
Option B. support the exhaust cone and straighten the gas flow.
Option C. support the exhaust cone only.
Option B. support the exhaust cone and straighten the gas flow.
- A nozzle is ‘choked’ when the engine inlet airflow is.
Option A. subsonic.
Option B. supersonic.
Option C. subsonic or supersonic.
Option C. subsonic or supersonic.
- What is the maximum practical angle through which the gas flow can be turned during thrust
reversal?.
Option A. 180°.
Option B. 50°.
Option C. 135°.
Option C. 135°.
- A supersonic duct is.
Option A. convergent then divergent along its length.
Option B. divergent then convergent along its length.
Option C. a convergent duct that is choked at the largest end at mach 1.
Option A. convergent then divergent along its length.
- Noise from the jet wake when untreated by suppression is.
Option A. high frequency, high decibel.
Option B. low frequency, low decibel.
Option C. low frequency, high decibel.
Option C. low frequency, high decibel.
- Hot spots on the tail cone of a turbine engine are possible indicators of a malfunctioning fuel
nozzle or.
Option A. a faulty igniter plug.
Option B. an improperly positioned tail cone.
Option C. a faulty combustion chamber.
Option C. a faulty combustion chamber.
- An exhaust cone placed aft of the turbine in a jet engine will cause the pressure in the first part of the exhaust duct to.
Option A. increase and the velocity to decrease.
Option B. decrease and the velocity to increase.
Option C. increase and the velocity to increase.
Option A. increase and the velocity to decrease
- A convergent-divergent nozzle.
Option A. requires the aircraft to be travelling at supersonic speeds.
Option B. makes maximum use of pressure thrust.
Option C. produces a type of thrust known as kinetic thrust.
Option B. makes maximum use of pressure thrust.
- The velocity of supersonic air as it flows through a divergent nozzle.
Option A. decreases.
Option B. increases.
Option C. is inversely proportional to the temperature.
Option B. increases.
- The Jet Pipe of a gas turbine engine.
Option A. protects the airframe from heat damage.
Option B. has an inner cone to protect the rear turbine disc.
Option C. is convergent in shape to increase the velocity as much as possible.
Option A. protects the airframe from heat damage.
- For what purpose is the propelling nozzle of a gas turbine engine designed?.
Option A. To increase the velocity and decrease the pressure of the gas stream leaving the nozzle.
Option B. To decrease the velocity and increase the pressure of the gas stream leaving the nozzle.
Option C. To increase the velocity and pressure of the gas stream leaving the nozzle.
Option A. To increase the velocity and decrease the pressure of the gas stream leaving the nozzle
- If the exit area of the nozzle was too large, the effect is.
Option A. exit velocity lower causing loss of thrust.
Option B. will choke at a lower gas temperature.
Option C. exit velocity lower, negligible effect on thrust.
Option A. exit velocity lower causing loss of thrust.
- A choked nozzle.
Option A. increases thrust.
Option B. decreases thrust.
Option C. has no effect on the thrust.
Option C. has no effect on the thrust.
- The exhaust section is designed to.
Option A. increase temperature, therefore increasing velocity.
Option B. decrease temperature, therefore decreasing pressure.
Option C. impart a high exit velocity to the exhaust gases.
Option C. impart a high exit velocity to the exhaust gases.