DOC AIRBUS | AMM A320FENGINE - GENERAL - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
The engine assembly is a dual-rotor, variable stator, high by-pass ratio turbofan power plant. The single stage fan and 3-stage booster are driven by a 7-stage Low Pressure Turbine (LPT). The 10-stage High Pressure Compressor (HPC) is driven by a 2-stage High Pressure Turbine (HPT). A second generation twin annular premixing swirler combustion chamber converts fuel and compressor discharge air into energy to give engine thrust and to drive the turbine. The accessory drive system gets energy from the HPC rotor to drive the engine accessories and the aircraft accessories that are installed on the engine. Reverse thrust for braking the aircraft after landing is supplied by an integrated system which acts on the fan discharge airflow.
** ON A/C NOT FOR ALL The engine assembly is a dual-rotor, variable stator, high by-pass ratio turbofan power plant. The single stage fan and 3-stage booster are driven by a 7-stage Low Pressure Turbine (LPT). The 10-stage High Pressure Compressor (HPC) is driven by a 2-stage High Pressure Turbine (HPT). A second generation twin annular premixing swirler combustion chamber converts fuel and compressor discharge air into energy to give engine thrust and to drive the turbine. The accessory drive system gets energy from the HPC rotor to drive the engine accessories and the aircraft accessories that are installed on the engine. Reverse thrust for braking the aircraft after landing is supplied by an integrated system which acts on the fan discharge airflow.
Engine - General2. System Description
The primary modules of the engine assembly are as follows:
Compressor module consists of fan and booster module, No. 1 and No. 2 bearing support module, fan case module, fan frame module and HPC rotor/stator assembly.
Combustion module consists of combustion case assembly and combustion chamber assembly.
Turbine module consists of HPT nozzle, HPT rotor, HPT case, LPT nozzle module, LPT shaft module, LPT rotor and stator module and Turbine Rear Frame (TRF).
Accessory drive module consists of Inlet Gearbox (IGB) & No. 3 bearing assembly, Transfer Gearbox (TGB) assembly and Accessory Gearbox (AGB) assembly.
** ON A/C NOT FOR ALL The primary modules of the engine assembly are as follows:
Compressor module consists of fan and booster module, No. 1 and No. 2 bearing support module, fan case module, fan frame module and HPC rotor/stator assembly.
Combustion module consists of combustion case assembly and combustion chamber assembly.
Turbine module consists of HPT nozzle, HPT rotor, HPT case, LPT nozzle module, LPT shaft module, LPT rotor and stator module and Turbine Rear Frame (TRF).
Accessory drive module consists of Inlet Gearbox (IGB) & No. 3 bearing assembly, Transfer Gearbox (TGB) assembly and Accessory Gearbox (AGB) assembly.
3. Component Description
A. Compressor Module
(1) The fan and booster module consists of a front stage, a fan stage of 18 blades and a 3-stage axial booster, cantilever-mounted at the rear of the fan disk. The fan and booster module is located behind the air intake section. Through the fan disk, it is attached to and supported by the Low Pressure Compressor (LPC) shaft. The LPC shaft is driven by the LPT. Through the booster outer shroud it is attached to and supported by the fan frame.
(2) The No. 1 and No. 2 bearing support module is located in the forward sump between the fan and booster module and the fan frame module. It is supported by the fan frame. It consists of a LPC shaft, two bearing supports, two bearings (front roller bearing and rear ball bearing), a load reduction device, a lubrication system, a front sealing system and the speed sensor wheel.
(3) The fan case module is located behind the air intake section and supported by the fan frame module. It consists of the fan case with a heat protection, an abradable assembly, a forward acoustic shroud, rear acoustic panels and stiffener plates.
(4) The fan frame module has the engine mounting located at 12 o'clock on the rear flange of the fan hub. It consists of a fan frame shroud, a set of Outlet Guide Vanes (OGVs), an engine kit, a fan hub, a Variable Bleed Valve (VBV) door system and an oil distributor.
The main functions of the fan frame module:
The main functions of the fan frame module:
- To direct and ensure a smooth aerodynamic airflow.
- To support the engine.
- To transmit power plant thrust to the aircraft.
(5) The HPC is located between the fan frame module and the HPT module. The shape of each compressor rotating blade incorporates the latest 3D-aero technology designed to efficiently move air to the next higher (rear) stage. The HPC is a 10-stage axial flow compressor.
(a) The HPC rotor with stages 1 to 5 blisk and stage 6 to 10 rotor spool. Stages 6 to 10 have axial dovetail slots. The rotor blades for each stage are attached with two locking lugs to prevent circumferential movement.
(b) The HPC front stator consists of the Inlet Guide Vanes (IGV) and the forward compressor stator case with four stages of Variable Stator Vanes (VSV). Forward compressor stator case is divided into two matched halves with flanges at the 3 and 9 o'clock positions. Borescope ports are provided at each HPC stage for internal inspections.
(c) The HPC rear stator contains five stages of fixed compressor stator vanes. Borescope ports are provided at each HPC stage for internal inspections.
B. Combustion Module
(1) The combustion section is located between HPC and HPT. The combustion section consists of the combustion case assembly and the combustion chamber assembly. The combustion section mixes fuel and HPC air for efficient and uniform combustion. It is the structural interface, transmits the engine axial load and provides the gas flow path between the compressor and the HPT. The combustion case has four borescope ports for internal inspections of the combustion chamber assembly. The combustion case has a port to be used for reading pressure by the pressure sub-system box of the control system.
(2) The combustion chamber assembly consists of 19 twin annular premixing swirler fuel nozzles, two igniters, combustion chamber dome, inner liner, outer liner, radial mixer and the inner and outer baffle. The HPC discharge air from the diffuser is used for cooling the combustion chamber.
C. Turbine Module
(1) The turbine section consists of the stage 1 HPT nozzle assembly HPT rotor assembly, HPT case and stage 2 nozzle assembly, Turbine Center Frame (TCF) assembly, LPT stage 1 nozzle module, LPT shaft module, LPT rotor & stator module and TRF module. The main purpose of the turbine section is to provide rotational energy to the compressor section.
(a) The HPT is located between the combustion section and the TCF assembly. The HPT is 2-stage turbine with 60 stage 1 blades and 68 stage 2 blades. The HPT extracts the energy from the hot gases exiting the combustion chamber, to drive the HPC, the IGB which drives the TGB and the AGB.
(b) The LPT is a 7-stage turbine. It is located between the TCF assembly and the TRF module. The LPT extracts the energy from the hot gases exiting the HPT, to drive the fan and booster rotor.
(c) The stage 1 HPT nozzles are physically located in the aft end of the combustion case. The stationary stage 1 HPT stator nozzles are needed to direct air to the HPT rotor blades. The stage 2 HPT nozzles contain holes visible from the flow path for cooling.
(d) The stage 1 LPT nozzle module is physically located between the aft end of the TCF and forward end of the LPT rotor and stator assembly. The other LPT stator module is located between the LPT stage 1 nozzle module, LPT shaft module and the TRF module.
(e) The TRF is located at the end of LPT rotor & stator module. The TRF engine mounts are attached by clevis mounts to the pylon rear attachment
The functions of TRF:
The functions of TRF:
- To support engine and cowlings.
- To direct and ensure a smooth aerodynamic airflow.
D. Accessory Drive Module
(1) The accessory drive module consists of the IGB module and No. 3 bearing, the TGB module and the AGB module. In running mode, the purpose of the accessory drive module is to provide engine and aircraft rotational accessories with rotational energy. In starting mode, the purpose of the accessory drive module is to provide the engine core with rotational energy from the pneumatic air starter.
(a) The IGB and the No. 3 bearing is located in the forward sump of the engine, secured on the fan frame assembly. The TGB and AGB are located on the fan frame at 8 o'clock position.
4. Bearings and Seals
A. Bearings
The engine rotors are supported by bearings installed in the sump cavities of the two frames. The forward sump is in the fan frame and holds the bearings No. 1, No. 2 (fan shaft) and No. 3 (HPC front shaft forward part). The aft sump is installed in the TRF and holds the bearings No. 4 (HPT rear shaft aft part) and No. 5 (LPT shaft aft part).
The engine rotors are supported by bearings installed in the sump cavities of the two frames. The forward sump is in the fan frame and holds the bearings No. 1, No. 2 (fan shaft) and No. 3 (HPC front shaft forward part). The aft sump is installed in the TRF and holds the bearings No. 4 (HPT rear shaft aft part) and No. 5 (LPT shaft aft part).
B. Oil Distribution
The bearings must be lubricated and oil is distributed to these components by nozzles. However, as the oil must be in the engine, seals of various types are installed to keep the oil and direct its recirculation.
The bearings must be lubricated and oil is distributed to these components by nozzles. However, as the oil must be in the engine, seals of various types are installed to keep the oil and direct its recirculation.
C. Seals Arrangement
The arrangement of oil and air seals, the provisions for oil supply, oil scavenge, seal pressurization and sump vent subsystems make a dry sump system. Engine sumps are vented to ambient pressure through the front, center and rear vent tubes which are installed in the LPT shaft.
The arrangement of oil and air seals, the provisions for oil supply, oil scavenge, seal pressurization and sump vent subsystems make a dry sump system. Engine sumps are vented to ambient pressure through the front, center and rear vent tubes which are installed in the LPT shaft.
D. Bearing Functions
Bearings decrease the rolling friction, support the rotors axially and radially within the engine structure. The bearings hold the rotors relative to the stators. The bearing must control the forces of gravity weight, aerodynamic loads of pumping and turbine driving. The bearings also control the gyroscopic loads due to aircraft maneuvers.
Bearings decrease the rolling friction, support the rotors axially and radially within the engine structure. The bearings hold the rotors relative to the stators. The bearing must control the forces of gravity weight, aerodynamic loads of pumping and turbine driving. The bearings also control the gyroscopic loads due to aircraft maneuvers.