Turbine Engine Inlet Systems

Question 1

Describe the purpose, design, and principles of operation of the engine inlet duct

Answer 1

• Inlet ducts are designed to allow the maximum airflow into the compressor
• Used to straighten the airflow and increase the pressure

Question 2

Describe the purpose of a subsonic divergent duct

Answer 2

• If intake air approaching engine is subsonic, is used to reduce the velocity and increase the pressure of the air on entry to the engine.
• Referred to as ram rise, ram effect, or ram recovery.
• Can cause the ar to separate from the intake wall and become turbulent - can cause compressor stall.
• Intake is designed to match the climb and cruise speeds to minimise losses - most common.