"PITOT" air intake: they are convergent in shape.

3 Converging-divergent type with variable section.

2 "PITOT" air intake: they are divergent in shape.

Subsonic Pitot

Supersonic Pitot

Conver-Diver

Subsonic

Sonic

Supersonic

A thermal phenomenon – interaction chock wave / boundary layer

A vibratory phenomenon – interaction chock wave / boundary layer 2

A vibratory phenomenon – interaction normal shock / oblique shock. 3

1 Independent of flight speed.

2 Proportionate to flight speed.

3 Inversely proportional to the temperature of the flame.

Rotor

Generator

Stator

A series of converging or divergent channels as appropriate

Its an obstacle

Venturi nozzle

1 They say the profiles are shock absorbers.

They say the profiles are straighteners

They say the profiles are deviant

Vabsolute = Wrelative + Utraining

W^2=U^2 +V^2

Vabsolute + Wrelative + Utraining = 0

Increase

Decrease

Increase

Decrease

1 The absolute speed located in the outlet of the rotor seen by the rotating grate (rotor).

2 The relative speed located in the outlet of the rotor seen by the rotating grate (rotor).

3 The absolute speed located in the outlet of the rotor seen by the stationary part of the engine.

1

2

3

1 The pressure gained in the stage is equal in the stator and in the rotor: so ΔErotor = ΔEstator

2 The stage gained all pressure in the rotor: ΔEstator = 0

3 The stage gained all pressure in the stator: ΔErotor = 0

S, P, V increase

S, P increase V Decrease

S Decrease, P, V Increase

1 The AoA of the profile’s fin is small and an aerodynamic stall appear on the upper surface of the first stage’s rotor

.2 The AoA of the profile’s fin is too large and the first stage’s rotor works in windmil

3 The AoA of the profile’s fin is too small and the last stage’s rotor works in windmill. A reversal flow of air appears on the last stage of the compressor.

True

False

Increase

Decrease

1 The double compressor assembly: High-Pressure compressor following by a Low-Pressure compressor.

2 The double compressor assembly: Low Pressure compressor following by a High-Pressure compressor.

3 The double flux nozzle: primary flow generated by the gas turbine and the secondary flow generated by the fan

Of the first stages, A

Of the first stages and of the last stages simultaneously. B

Of the first stage only. C

Due to the high inertia of N1, the aerodynamic link between N1 and N2 does not permit to decelerate N1 immediately. That imposes on the N2 an air flow greater than what it can evacuate. The compressor can surge

Due to the high inertia of N1, the aerodynamic link between N1 and N2 does not permit to decelerate N1 immediately. That imposes on the N2 an air flow greater than what it can evacuate. The compressor works normally

The aerodynamic link between N1 and N2 permit to decelerate N1 immediately. That imposes on the N2 an air flow suitable with the condition of operation. The compressor can surge

Fan fins and compressor fins are welded to the disk

Fan fins and compressor fins are fixed to the disk by using the technic of the “Christmas tree” form

Fan fins and compressor fins are fixed to the disk by a device composed of dovetail foot, dovetail groove and brake pads

Igniter

Ball bearing

Fuel nozzle

Nozzle guide vane

Combustion liner

Swirlers guide vane

Ball bearing

Roll bearing

Bearing

1 Avoid flow turbulence as much as possible in the inlet section of the chamber,

2 Ensure a regular supply of air and fuel in the combustion chamber,

3 Ensure a regular supply of air and fuel and avoid flow turbulence as much as possible in the inlet section of the chamber

1 empirical air/fuel ratio.

2 air/fuel ratio.

3 Stoechiometric air/fuel ratio.

1 This is the secondary flow and its temperature is around 450 °C

2 This is the primary flow and its temperature is around 450 °C

3 This is the tertiary flow and its temperature is around 450 °C

1 Zone of extinction – no combustion is possible

2 Zone of combustion – no combustion is possible

3 Zone of combustion – combustion is possible

1 there is too much fuel compared to air in the mixture and thus the combustion is no possible. This limit is called: the rich limit

2 there is too much air compared to fuel in the mixture and thus the combustion is no possible. This limit is called: the weak limit

3 there is too much air compared to fuel in the mixture and thus the combustion is possible. This limit is called: the weak limit

The higher the combustion pressure, the greater the range of operation. The pressure destabilized the combustion

The lower the combustion pressure, the greater the range of operation. The pressure stabilized the combustion

3 The higher the combustion pressure, the greater the range of operation. The pressure stabilized the combustion

1 Zone of extinction – no combustion is possible

2 Zone of combustion – no combustion is possible

3 Zone of combustion – combustion is possible

1 there is too much fuel compared to air in the mixture and thus the combustion is no possible. This limit is called: the rich limit

.2 there is too much air compared to fuel in the mixture and thus the combustion is no possible. This limit is called: the weak limit

3 there is too much air compared to fuel in the mixture and thus the combustion is possible. This limit is called: the weak limit

1

2

3

1

2

3

1 The flow identified “C” is called tertiary flow: it participates to the generation of the parabolic temperature profile in the turbine oulet section

2 The flow identified “C” is called tertiary flow: it participates to the cooling of the combustion casing.

3 The flow identified “C” is called tertiary flow: it participates to the generation of the parabolic temperature profile in the turbine inlet section

1

2

3

1 Generally, the combustion liner is made of Refractory steels,

2 Generally, the combustion liner is made of Maraging steels

3 Generally, the combustion liner is made of Stainless steels

1 0,3 % of Carbon, 19 % of Chrome and 10 % of Nickel and traces of manganese.

2 0,3 % of Carbon, 19 % of Chrome and 10 % of Nickel.

3 0,3 % of Carbon, 19 % of Chrome and 10 % of Nickel and traces of siliceous.

A

B

C

1 Several individual chamber housing and individual combustion liner located both around the engine. Each combustion liner is connected to the other by an intercommunication manifold.

2 One chamber housing and one combustion liners goes both around the engine. this type of combustion chamber is widely used in modern engines.

3 Several individual combustion liner located both around the engine and one combustion casing located around the engine.

1 Several individual chamber housing and individual combustion liner located both around the engine. Each combustion liner is connected to the other by an intercommunication manifold

2 One chamber housing and one combustion liners which goes both around the engine. this type of combustion chamber is widely used in modern engines.

3 Several individual combustion liners located around the engine and one combustion casing which goes around the engine.

1 Participate in engine rigidity, Easy setting and testing, Easy maintenance and Good control of the combustion

2 lightness, weak diametral, Low pressure drop, Good ratio Power/Weight and Participate in engine rigidity.

3 Easy cooling, Easy setting and testing, Easy maintenance, Good control of the combustion and Participate in engine rigidity

1The “Take-off head” which permit to reduce pollutants CO and CH4 and the “idle head zone” which permit to Reduce pollutant NO.

2The “idle head zone” which permit to reduce pollutants NO and CH4 and the “Take-off head” which permit to Reduce pollutant CO.

3The “idle head zone” which permit to reduce pollutants CO and CH4 and the “Take-off head” which permit to Reduce pollutant NO.

1 In the same time, between idle and take-off/cruise the fuel pressure ratio is 600.

2In the same time, between idle and take-off/cruise the fuel pressure ratio is 900.

3 In the same time, between idle and take-off/cruise the fuel pressure ratio is the same.

1The pressure on the control valve piston is not sufficient to counterbalance the force exerted by the spring. The control valve remains closed and only the primary circuit is supplied:idle condition.

2The pressure on the control valve piston is sufficient to counterbalance the force exerted by the spring. The control valve is open and both circuit are supplied: take-off and cruise conditions.

3 The pressure on the control valve piston is sufficient to counterbalance the force exerted by the spring. The control valve is open and both circuit are supplied: idle conditions.

1it is necessary to impart a high rotational speed to the fuel and in a direction opposite to that given to the air by swirling grate.

2it is necessary to impart a low rotational speed to the fuel and in a direction opposite to that given to the air by swirling grate

3 it is necessary to impart a high rotational speed to the fuel and in the same direction to that given to the air by swirling grate.

1 The number of turbine stages is always greater than the number of stages of the compressor.

2 The number of turbine stages is always lower than the number of stages of the compressor.

3 The number of turbine stages is equal to the number of stages of the compressor.

TRUE

FALSE

TRUE

FALSE

1

2

3

1In acceleration, TC assembly leaves the stabilized regime point A on the adaptive line in order to reach the stabilized regime point C by following the adaptative line

2In deceleration, TC assembly leaves the stabilized regime point A on the adaptive line in the right direction in order to reach the stabilized regime point C by a succession of transient regime points.

3In deceleration, TC assembly leaves the stabilized regime point A on the adaptive line in the left direction in order to reach the stabilized regime point C by a succession of transient regime points

1 the deceleration transient move strongly on the right side and can reach the weak extinction zone

2 the deceleration transient move on the left side and may pass through the surging area.

3 the deceleration transient move strongly on the left side, may pass through the surging area and reach the rich extinction zone

1 Does not cause any major engine malfunctions.

2 This carries the risk of engine extinction with each acceleration.

3 This carries the risk of the compressor stalling with each acceleration.

1 Un-alloy steels,

2 Weakly alloy steels

3 Strong alloy steels

1 Steels that withstand creep.

2 Steels that withstand creep and corrosion at high temperature.

3 Steels that withstand creep and high temperature.

1 The monocrystalline structure is obtained without help of primer in the mold.

2The solidification is obtained from only one primer located at the top of the mold to obtain a monocrystalline structure

3 The solidification is obtained from only one primer located in the bottom of the mold to obtain a monocrystalline structure

1 allow to extends the life of the turbine's fins up to 2500 hours

2 allow to extends the life of the turbine's fins up to 5000 hours

3 allow to extends the life of the turbine's fins up to 10000 hours.

1 LP compressor. The thermal stresses in this area are mitigated by the protective film that envelops blades and fins. The LP flow at 130°C is enough to cool the trailing edge.

2The fan. The thermal stresses in this area are mitigated by the protective film that envelops blades and fins. The BP flow at 130°C is enough to cool the trailing edge

3 HP compressor. The thermal stresses in this area are mitigated by the protective film that envelops the wing. The BP flow at 130°C is enough to cool the trailing edge.

1 the rotor fins undergo a variation of length due to traction type load.

2 the stator blades undergo a variation of length due to creep type load.

3 the rotor fins undergo a variation of length due to creep type load.

1 Inlet section of the nozzle makes it possible to create the propulsion force: the thrust.

2 outlet section of the nozzle makes it possible to create the drag force.

3 Outlet section of the nozzle makes it possible to create the propulsion force: the thrust.

1 Ejection nozzle

2 Exhaust pipe

3 Exhaust cone diffuser

1 The primary and secondary nozzle are both variable geometries.

2 The primary nozzle is variable geometry and the secondary nozzle is fixed geometry.

3 The primary and secondary nozzle are both fixed geometries.

1 corresponds to the annular section of the primary nozzle

2 corresponds to the annular section of the secondary nozzle

3 corresponds to the circular section of the secondary nozzle

1 the forward part of the engine. It is composed of the exhaust cone fixed to the nacelle of the engine and the central body.

2 the forward part of the engine. It is composed of the exhaust cone and the central body fixed to the nacelle of the engine. 3 the rear part of the engine. It is composed of the exhaust cone fixed to the nacelle of the engine and the central body.

3 the rear part of the engine. It is composed of the exhaust cone fixed to the nacelle of the engine and the central body.

1

2

3

1 The nozzle is said adapted when the MACH number in the outlet section is one and the mass flow is maximum.

2 The nozzle is said adapted when the MACH number in the outlet section is lower than one and the mass flow is maximum

3 The nozzle is said adapted when the MACH number in the outlet section is one and the mass flow is minimum.

1 on the study of the ratio P∞ / PT4

2 on the study of the ratio P5 / PT4

3 on the study of the ratio Pc / PT4

1

2

3

1

2

3

1

2

3

1

2

3

1

2

3

1

2

3

1 with afterburner the thrust is multiply by three with an increase of specific consumption of 50%.

2 with afterburner the thrust is multiply by two with an increase of specific consumption of 30%.

3 without afterburner the thrust is multiply by two with an increase of specific consumption of 30%.

1 Afterburner is ON the level of sound emitted is very high and the specific consumption decreases strongly

2 Afterburner is ON the level of sound emitted is very high and the specific consumption increases strongly.

3 Afterburner is ON the level of sound emitted is very low and the specific consumption increases strongly

1

2

3

1

2

3