FAA Aviation Mechanic Powerplant (AMP)Turbine EnginesMedium
A mechanic is studying the turbine section of a gas turbine engine. Which stationary component is located immediately downstream of the combustion section and directs and accelerates the hot gases onto the first-stage turbine rotor blades?
- ATurbine nozzle (guide vanes)
- BExhaust cone
- CCompressor stator vanes
- DDiffuser case
Show answer & explanationAnswer & explanation
Correct answer: A. Turbine nozzle (guide vanes)
The turbine nozzle, also called turbine guide vanes or the first-stage stator, is a ring of stationary airfoils immediately after the combustor that converts the gas pressure into velocity and directs it at the optimum angle onto the turbine rotor blades to extract maximum energy.
Why the other options are wrong
- B. The exhaust cone is at the rear of the engine, downstream of all turbine stages.
- C. Compressor stator vanes are part of the compressor section, upstream of the combustor.
- D. The diffuser is located at the compressor discharge, before the combustor, not after it.
Turbine Nozzle (Guide Vanes)
A stationary ring of airfoil-shaped vanes located immediately after the combustor that accelerates and directs combustion gases onto the turbine rotor blades.
- Converts pressure energy to velocity energy
- Sets the correct gas flow angle for turbine rotor blades
- Subject to extreme heat, often air-cooled
Memory trick: Nozzle = the 'aiming device' that points hot gas straight at the spinning turbine blades.