DOC AIRBUS | AMM A320FAIR INLET SECTION - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. General
This section will analyze the fan and booster module (Ref. AMM D/O 72-21-00-00) which consists of a front stage, a fan stage 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 and is contained by the fan case and fan frame assemblies. Through the fan disk, it is attached to and supported by the compressor shaft, attached to the LP shaft and driven by the Low Pressure Turbine (LPT). Through the booster outer shroud it is attached to and supported by the fan frame.
** ON A/C NOT FOR ALL This section will analyze the fan and booster module (Ref. AMM D/O 72-21-00-00) which consists of a front stage, a fan stage 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 and is contained by the fan case and fan frame assemblies. Through the fan disk, it is attached to and supported by the compressor shaft, attached to the LP shaft and driven by the Low Pressure Turbine (LPT). Through the booster outer shroud it is attached to and supported by the fan frame.
2. System Description
The front stage is composed of the spinner front and the front platform shroud.
The front spinner is attached to the front platform shroud by nine screws. It is made of aluminum alloy with anodiziation. It is an aerodynamic fairing, its function is to direct and to provide a smooth aerodynamic surface for airflow to feed fan stage.
Its profile is optimized in order to protect the fan blades against Foreign Object Damage (FOD) and icing phenomenon and to reduce noise level.
The front platform shroud is attached to fan disk by 18 screws. It is made of titanium. Its function is to provide a smooth aerodynamic surface for airflow. It receives the fan blade balance weights, used to balance the engine assembly. A fracture of fan blade balance weights is impossible as there is no load applied on them. As FOD is not considered in MSG3 analyses, a fracture of the front platform shroud is not possible in normal operations and conditions.
** ON A/C NOT FOR ALL The front stage is composed of the spinner front and the front platform shroud.
Air Inlet SectionThe front spinner is attached to the front platform shroud by nine screws. It is made of aluminum alloy with anodiziation. It is an aerodynamic fairing, its function is to direct and to provide a smooth aerodynamic surface for airflow to feed fan stage.
Its profile is optimized in order to protect the fan blades against Foreign Object Damage (FOD) and icing phenomenon and to reduce noise level.
The front platform shroud is attached to fan disk by 18 screws. It is made of titanium. Its function is to provide a smooth aerodynamic surface for airflow. It receives the fan blade balance weights, used to balance the engine assembly. A fracture of fan blade balance weights is impossible as there is no load applied on them. As FOD is not considered in MSG3 analyses, a fracture of the front platform shroud is not possible in normal operations and conditions.
3. Component Description
A. Fan Stage
(1) The fan stage consists of the LP compressor cover, the fan disk and 18 fan blades, platforms, spacers, locks and shields.
(a) Cover function
The cover function is to protect the internal part of the compressor shaft and the LPT shaft against sand and dust pollution and is used as a nut retainer. It is made of titanium.
A failure of the LP compressor cover is not possible in normal operations and conditions for the following reasons: a fracture is impossible as no load applied, it is made of resistant titanium material, consequently erosion is negligible and major erosion is not possible under normal conditions and there is no relative displacement, so no chafing is considered.
The cover function is to protect the internal part of the compressor shaft and the LPT shaft against sand and dust pollution and is used as a nut retainer. It is made of titanium.
A failure of the LP compressor cover is not possible in normal operations and conditions for the following reasons: a fracture is impossible as no load applied, it is made of resistant titanium material, consequently erosion is negligible and major erosion is not possible under normal conditions and there is no relative displacement, so no chafing is considered.
(b) Fan disk function
The fan disk function is to provide mechanical coupling of fan blades. It is titanium alloy forging and has 18 dovetail slots for installation of fan blades. It is attached to the compressor shaft by a slotted nut and supports the booster spool, attached by 18 screws. A shim is placed between the fan disk and the compressor shaft to take up the axial tolerance of the No. 1 and No. 2 bearing support module (Ref. AMM D/O 72-22-00-00).
The compressor shaft (Ref. AMM D/O 72-22-00-00) supports the fan disk which drives the fan blades. Fan disk is protected by a shield made with Inconel 718 to reduce fretting vulnerability.
The fan disk is a life limited part.
The fan disk function is to provide mechanical coupling of fan blades. It is titanium alloy forging and has 18 dovetail slots for installation of fan blades. It is attached to the compressor shaft by a slotted nut and supports the booster spool, attached by 18 screws. A shim is placed between the fan disk and the compressor shaft to take up the axial tolerance of the No. 1 and No. 2 bearing support module (Ref. AMM D/O 72-22-00-00).
The compressor shaft (Ref. AMM D/O 72-22-00-00) supports the fan disk which drives the fan blades. Fan disk is protected by a shield made with Inconel 718 to reduce fretting vulnerability.
The fan disk is a life limited part.
(c) Fan blades
Fan blades are solid wide chord 3D design to optimize aerodynamic performance to increase fan air flow. Their function is to provide kinetic energy to airflow. They are made of 3D woven composite material with leading edge of titanium. Wear strips are placed on the interfaces of the blade with the fan disk, the platforms, the individual lock and the booster spool to reduce fretting vulnerability. Per design, no lubrication of the fan blade root is necessary.
Under each fan blade, spacers hold it in the correct radial position. Spacers are made of composite material. They bear the fan blades in rest position and maintain them tightly. Fan blades are axially maintained by the individual lock.
Fan blades are solid wide chord 3D design to optimize aerodynamic performance to increase fan air flow. Their function is to provide kinetic energy to airflow. They are made of 3D woven composite material with leading edge of titanium. Wear strips are placed on the interfaces of the blade with the fan disk, the platforms, the individual lock and the booster spool to reduce fretting vulnerability. Per design, no lubrication of the fan blade root is necessary.
Under each fan blade, spacers hold it in the correct radial position. Spacers are made of composite material. They bear the fan blades in rest position and maintain them tightly. Fan blades are axially maintained by the individual lock.
(d) Fan blade platforms
The fan blade platforms are made of composite material. They are mounted between the fan blades to form the flow path of the fan hub and to make the airflow smooth.
A lock is positioned in front of the fan blade root to hold it in axial position before the mounting of the front platform shroud. The fan blade locks are made of titanium and honeycomb (that buckles in case of very high axial forces to dissipate energy).
The fan blade platforms are made of composite material. They are mounted between the fan blades to form the flow path of the fan hub and to make the airflow smooth.
A lock is positioned in front of the fan blade root to hold it in axial position before the mounting of the front platform shroud. The fan blade locks are made of titanium and honeycomb (that buckles in case of very high axial forces to dissipate energy).
(e) Booster
The Booster is a three-stage axial flow compressor consisting of:
The Booster is a three-stage axial flow compressor consisting of:
- Three-stage rotor spool and blades
- Four-stage stator vanes.
(f) Flow splitter system
The flow splitter system is composed of the flow splitter, the flow path fairing and two half flow path fairing ring.
The functions of the flow splitter are:
The flow splitter system is composed of the flow splitter, the flow path fairing and two half flow path fairing ring.
The functions of the flow splitter are:
- To separate primary and secondary air flows
- To evacuate the hot air coming from the anti-ice tubes in the primary flow to avoid ice accumulation on the splitter forward end.
(g) Flowpath fairing function
The flowpath fairing function is to provide an aerodynamic smooth surface for secondary airflow. It is made of aluminium. The two half flow path fairing rings make the link between the flow splitter and the flow path fairing. It is made of aluminium. They are bolted to the flow splitter. The flowpath fairing has 2 ports at the 4 o'clock position (ALF) for gaspath borescope inspection.
The flowpath fairing function is to provide an aerodynamic smooth surface for secondary airflow. It is made of aluminium. The two half flow path fairing rings make the link between the flow splitter and the flow path fairing. It is made of aluminium. They are bolted to the flow splitter. The flowpath fairing has 2 ports at the 4 o'clock position (ALF) for gaspath borescope inspection.
NOTE: There is no plug associated to borescope holes and a clogging of borescope holes is impossible given the diameter of the holes.