DOC AIRBUS | AMM A320FAIR - GENERAL - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
The air system covers primary, secondary (bypass) and parasitic (cooling and pressurizing) airflows and the systems used to control the airflow. It is composed in 2 major sections.
The air system covers primary, secondary (bypass) and parasitic (cooling and pressurizing) airflows and the systems used to control the airflow. It is composed in 2 major sections.
Turbine Control - SchematicA. Engine Section
The airstream flowing through the IAEV2500 turbofan engine supplies 2 majors systems:
The airstream flowing through the IAEV2500 turbofan engine supplies 2 majors systems:
(1) The internal air system, which consists of the following subsystems:
(a) Propulsion airflow (secondary and primary flows).
(b) Bearing compartments pressurizing air.
(c) Cooling air.
(2) The external air system, which consists of the following subsystems:
(a) HP/LP turbine active clearance control.
(b) High-energy igniter harness cooling air.
(c) Engine bleed air.
B. Nacelle Section
The nacelle installation is designed to provide cooling and ventilation air for engine accessories mounted along the fan and core casing.
The distribution and circulation of the air in the components is such that the temperature limit for specific components is not exceeded.
The nacelle installation is designed to provide cooling and ventilation air for engine accessories mounted along the fan and core casing.
The distribution and circulation of the air in the components is such that the temperature limit for specific components is not exceeded.
2. Component Location
** ON A/C NOT FOR ALL | ------------------------------------------------------------------------------- |
| FIN I FUNCTIONAL DESIGNATION I PANELIZONEIACCESS I ATA |
| I I I I DOOR I REF. |
| ------------------------------------------------------------------------------- |
| 4008KS SENSOR-NACELLE TEMPERATURE 454 452AR 75-41-15 |
| 4021KS ACTUATOR-MASTER, LPC BLEED 435 451AL 75-31-42 |
| 4022KS ACTUATOR-VSV 453 451AL 75-32-41 |
| 4023KS SOL VALVE-HP COMPRESSOR STAGE 10 436 438AR 75-32-53 |
| 4027KS ACTUATOR-ACC 454 452AR 75-24-52 |
| 4028KS SOL VALVE-STAGE 10 AIR 436 438AR 75-23-52 |
| 4025KS VALVE-STAGE 10 TO HPT AIR 453 451AL 75-23-51 |
| 4001JM VALVE-HPC STAGE 10 BLEED 454 452AR 75-32-54 |
| 4000JM BLEED VALVE-HP COMPRESSOR STAGE 7 453 452AR 75-32-52 |
| 4020KS SOL VALVE-HP COMPRESSOR STAGE 7 436 438AR 75-32-51 |
| 4021KS ACTUATOR-SLAVE,LP COMPRESSOR BLEED 435 452AR 75-31-43 |
| - VALVE-ACTIVE CLEARANCE CONTROL 454 452AR 75-24-51 |
| - N°4 BEARING COMPARTMENT AIR COOLER 453 451AL 75-22-41 |
3. Description
All engine air enters the front mounted fan through the engine air intake cowl. After being compressed by the fan, the airflow is divided into primary and secondary (bypass) airflows by the flow splitter in the fan frame. The logics of the air systems controlled by the FADEC are fully described in chapter 73-25-00.
All engine air enters the front mounted fan through the engine air intake cowl. After being compressed by the fan, the airflow is divided into primary and secondary (bypass) airflows by the flow splitter in the fan frame. The logics of the air systems controlled by the FADEC are fully described in chapter 73-25-00.
A. Propulsion Airflow System
(1) Secondary flow
Fan air passes through the Outlet Guide Vanes (OGV) and the fan frame struts.
Bypass air is discharged through the Common Nozzle Assembly (CNA) during normal engine functioning and provides the major portion of engine thrust (approximately 4/5 of the total airflow of the engine). When the thrust reverser is deployed, the bypass air is directed outward through the thrust reverser cascades to provide reverse thrust (Ref. chap. 78-30).
A small portion of the bypass air is used for HP/LP turbine active clearance control and environmental control system cooling through the precooler.
Fan air passes through the Outlet Guide Vanes (OGV) and the fan frame struts.
Bypass air is discharged through the Common Nozzle Assembly (CNA) during normal engine functioning and provides the major portion of engine thrust (approximately 4/5 of the total airflow of the engine). When the thrust reverser is deployed, the bypass air is directed outward through the thrust reverser cascades to provide reverse thrust (Ref. chap. 78-30).
A small portion of the bypass air is used for HP/LP turbine active clearance control and environmental control system cooling through the precooler.
(2) Primary flow
A portion of fan air passes into the 3-stage booster and enters the core by a converging duct formed by the fan frame. This duct is provided with Booster Stage Bleed Valves (BSBV). The air then enters the HP compressor which is provided with 7th and 10th stage bleed valves (required for engine stability during starting and transient conditions).
The compressed air enters the combustion chamber and is ignited with the fuel. The exhaust gases flow through the high pressure turbine (HPT) and the low pressure turbine (LPT) and are discharged through the Common Nozzle Assembly (CNA).
A portion of fan air passes into the 3-stage booster and enters the core by a converging duct formed by the fan frame. This duct is provided with Booster Stage Bleed Valves (BSBV). The air then enters the HP compressor which is provided with 7th and 10th stage bleed valves (required for engine stability during starting and transient conditions).
The compressed air enters the combustion chamber and is ignited with the fuel. The exhaust gases flow through the high pressure turbine (HPT) and the low pressure turbine (LPT) and are discharged through the Common Nozzle Assembly (CNA).
B. Bearing Compartments Pressurizing Air
(1) The bearing compartment pressure, to ensure satisfactory sealing, is obtained from the 6th stage compressor manifold for the N°'s 1, 2 and 3 bearings.
C. Engine Internal Cooling Air System
The engine internal cooling air system consists of two subsystems:
The engine internal cooling air system consists of two subsystems:
(1) The HP turbine cooling controlled air system which uses 10th stage HP compressor bleed air to cool the stage 2 turbine blades, both HP turbine disk bores and the LP turbine cavity, in response to EEC command.
(2) The HP turbine cooling air system which uses 10th stage HP compressor bleed air to cool the HP turbine case, the LP turbine support rails for the diffuser duct outer segments and the stage 2 vanes.
D. HP/LP Turbine Active Clearance Control
The HP and LP turbines are cooled by fan air drawn from a common HP/LP ACC air scoop in the fan duct and distributed to both turbine casings.
The HP and LP turbines are cooled by fan air drawn from a common HP/LP ACC air scoop in the fan duct and distributed to both turbine casings.
E. High Energy Igniter Harness Cooling Air
The ignition system is cooled by fan air which is directed to the exciter, the lead and igniter plug.
The ignition system is cooled by fan air which is directed to the exciter, the lead and igniter plug.
F. Engine Bleed Air
Two customer bleeds are available at stages 7 and 10 of the HPC.
Two customer bleeds are available at stages 7 and 10 of the HPC.
(1) The air intake cowl anti-icing system consists of ducting routing from a 7th stage engine dedicated bleed port to the air intake cowl.
An on-off valve controls the air supply to the air intake lip.
(Ref. chap. 30-21-00).
An on-off valve controls the air supply to the air intake lip.
(Ref. chap. 30-21-00).
(2) The environmental control system (ECS) pneumatic installation collects bleed air from either the engine 7th stage manifold or the engine 10th stage manifold and delivers bleed air through a pressure regulating valve to the pylon/nacelle assembly interface (Ref. chap. 36-11).
(3) ECS air cooling is provided through the precooler by air taken in the fan discharge.
4. Nacelle Temperature Indication
This system enables the nacelle core zone ambient temperature indication to be displayed.
This system enables the nacelle core zone ambient temperature indication to be displayed.