Engine Part 1 Flashcards
What is the primary function of the compressor?
To supply large masses of compressed air to the combustion section
Describe the compressor
The compressor is an 8-stage axial flow unit consisting of two major components, the stator and rotor assemblies.
Where is the engine mounted gearbox located?
It is attached to the bottom of the main frame
Describe the combustion main frame and its purposes:
The combustion main frame is the front part of the combustion section and is the primary structural component of the engine. It serves as a diffuser passage for compressed air entering the combustion section. The mainframe is also a mounting pad for the main fuel nozzles in the combustion section. The mainframe also bleeds air from the 8th stage compressor air to operate the engine and pneumatic systems
What are the 6 major sections of the J85 engine/
- Front Frame
- Compressor Section
- Combustion section
- Turbine Section
- Afterburner Section
- Exhaust nozzle
Each engine accessory is divided into what two sections?
- Engine Accesories (components required to operate the engine)
- Airframe mounted gearbox (components required for aircraft systems)
Each engine accessory is divided into what two sections?
- Engine Accesories (components required to operate the engine) 2. Airframe mounted gearbox (components required for aircraft systems)
What are the accessory sections of the engine driven by?
A power takeoff (PTO) from the engine compressor drive shaft
Where is the engine mounted gearbox located?
It is attached to the bottom of the main frame
Describe the combustion main frame and its purposes:
The combustion main frame is the front part of the combustion section and is the primary structural component of the engine. It serves as a diffuser passage for compressed air entering the combustion section. The mainframe is also a mounting pad for the main fuel nozzles in the combustion section. The mainframe also bleeds air from the 8th stage compressor air to operate the engine and pneumatic systems
What are the 5 major components of the combustion section?
- Igniter Plug.
- Fuel Nozzles
- Combustion Liner
- Inner Casings
- Outer Casings
What percentage of air is used to support combustion?
Less than 25%
What is the purpose of the combustion liner?
The combustion liner provides an efficient flow of air, allowing for combustion, between the inner and outer casings. The combustion liner also allows for air to flow between itself and the casings to provide protective cooling of the combustion chamber components
What is wrapped around the outer combustion casing?
An insulation blanket which shields the airframe components from excessive heat
What is the turbine section comprised of?
Stator and rotors
What is the primary purpose of the turbine section?
Extract energy from the high velocity airstream to drive the compressor and engine accesories.
What does T5 refer to?
Turbine discharge temperature
What does T5 refer to?
Turbine discharge temperature
What is the variable area exhaust nozzle assembly controlled by?
- Hydromechanical System
2. T5 System
What is the basic function of the T5 system?
To prevent excessive EGT beyond the upper 650 C limit
Around what engine RPM do the exhaust nozzles close to their smallest opening?
97%
Describe how the T5 system operates:
As the EGT reaches its maximum range (approx when throttles increase beyond approx 97%) the hydromechanical system is no longer in control and the T5 system takes over nozzle geometry. As power moves from 97% to MAX, the T5 system will maintain the EGT within the 630-650 C limit by opening the nozzles in crease cooling, rather than closing them tighter.