AGK Engines - Gas Turbine Air Intake Flashcards
Subsonic air intake must ensure that…
Engine receives correct quantity of air
Air is delivered to engine with minimum air loss
Airflow to engine is uniform/free of turbulence
Air is delivered at uniform pressure, evenly distributed across entire inlet area
What is a lip, throat and diffuser?
Lip is shaped to reduce flow separation in crosswinds and high AoA
Throat is slight convergent duct which leads to the diffuser
Diffuser generates an increase in pressure at the compressor inlet
Intake instability
Inner surface is smooth - minimise risk of generating turbulent flow
Significant crosswind across face of intake can disrupt smooth inflow (lead to hot/hung start)
Strong crosswind on t/o can cause instability and surge (risk reduced by rolling t/o)
Why is there an acoustic shroud around fan casing?
Why has distance between the lip of casing and the fan blades been extended?
Minimise noise from air entering the engine
To stabilise airflow
What can intake icing cause and how to prevent it?
Disrupts laminar airflow into engine
Starve engine of air and cause flame out
Damage to blades if ice breaks off
Lip is heated (bleed air/engine oil) to prevent ice
