Inlet systems, compressors

An Ideal intake duct would do what?

• Provide constant pressure airflow to the compressor under all flight conditions.

• Decrease the engine's initial power output to avoid compressor stall.

• Disrupt the airflow to the compressor to increase turbulence.

• Increase the temperature of the air entering the engine.

What is the purpose of an intake?

• Reduce drag and increase pressure

• Increase drag and decrease pressure

• Reduce pressure and deliver airflow to the fan/compressor face at an even pressure spread

• Increase pressure and redirect airflow onto the high pressure compressor

What does the air intake for a typical high bypass turbo fan do to the pressure and velocity of the air entering the compressor, is the duct convergent or divergent?

• Divergent, decreases velocity and increases pressure.

• Convergent, decreases velocity and increases pressure.

• Convergent, increases velocity and decreases pressure.

• Divergent, increases velocity and decreases pressure.

During a climb to altitude drag on the compressor blades:

• Increases giving good efficiency.

• Increases giving poor efficiency.

• Reduces giving good efficiency.

• Reduces giving poor efficiency.

The compressor idling speed of an uncompensated gas turbine engine will increase:

• at higher ambient temperature

• with higher than sea level density

• at altitudes lower than sea level

• at lower ambient temperature

What happens to airflow pressure and velocity through both rotors and stators in an axial flow compressor?

• Velocity decreases through rotors and decreases through stators and increases in pressure through both.

• Velocity decreases through rotors and increases through stators and decreases in pressure through both.

• Velocity increases through rotors and decreases through stators and increases in pressure through both.

• Velocity decreases through rotors and increases through stators and increases in pressure through both.

One stage of an axial flow compressor consists of:

• One rotor assembly and one row of stator vanes

• One stator assembly and one row of guide vanes

• One rotor and one impeller assembly

• One impeller and one diffuser assembly

As air passes through an axial flow compressor, a pressure rise takes place in:

• the impeller and the diffuser

• the rotor blades only

• both the rotor blades and the stator vanes

• the stator vanes only

The pressure rise across a centrifugal compressor:

• occurs in the impeller only

• occurs in the diffuser only

• is shared almost equally by the impeller and the diffuser

• is always greater in the diffuser than in the impeller

A centrifugal compressor turbine compared to an axil flow has the following advantage:

• Less frontal area

• Lower weight

• Less increase per stage

• Efficient over a range of mass flow and pressure ratio combinations