DOC AIRBUS | AMM A320FNACELLE COMPARTMENT AND ACCESSORY COOLING - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. General
The nacelle has three major compartments; the engine air intake, fan and core compartments. Each compartment is isolated from the other with separating bulkhead and seals. The fan and core compartments surround the engine and are exposed to engine case heat rejection and vapors from fluid leaks. These two compartments are cooled with forced air and have ventilation porting. The fan compartment has a flush air inlet located in the lower portion of the left-hand fan cowl. Air passes around the accessory gearbox cooling the components and carries away vapor leaks. The air exists the fan compartment through the vent port located in the upper quadrant of each fan cowl door. The vents are sized to relieve the air starter flow at high altitudes since the starter motor exhausts directly into the fan compartment.
The core compartment is cooled with air taken from the fan discharge path through 4 flush inlets and the LPT case cooling air contributes to the compartment ventilation. The air is vented at the rear of the compartment at the core/cowl primary nozzle interface.
The nacelle cooling and ventilation systems provide the following functions:
** ON A/C NOT FOR ALL The nacelle has three major compartments; the engine air intake, fan and core compartments. Each compartment is isolated from the other with separating bulkhead and seals. The fan and core compartments surround the engine and are exposed to engine case heat rejection and vapors from fluid leaks. These two compartments are cooled with forced air and have ventilation porting. The fan compartment has a flush air inlet located in the lower portion of the left-hand fan cowl. Air passes around the accessory gearbox cooling the components and carries away vapor leaks. The air exists the fan compartment through the vent port located in the upper quadrant of each fan cowl door. The vents are sized to relieve the air starter flow at high altitudes since the starter motor exhausts directly into the fan compartment.
Nacelle Cooling in FlightThe core compartment is cooled with air taken from the fan discharge path through 4 flush inlets and the LPT case cooling air contributes to the compartment ventilation. The air is vented at the rear of the compartment at the core/cowl primary nozzle interface.
The nacelle cooling and ventilation systems provide the following functions:
- Sufficient airflow to offset the effects of engine case heat rejection and engine flange air leakage, thereby maintaining an acceptable compartment temperature level.
- Cooling of Temperature Critical Components.
- Cowling Pressure Load Limiting in the Event of Pneumatic Duct Failures.
- Ventilation of Compartment during Engine Shutdown.
- Ventilation of Combustible Fluid Vapors to Preclude Fire.
2. Description
The fan-compartment ram air scoop and vent ports are of a low pressure load flush design. The 4 core compartment air inlets are located in the core cowl and provide fan air to obtain the necessary cooling. LPT case cooling air also contributes to compartment ventilation. Fan discharge air is drawn through the LPT ram air scoop mounted on the thrust reverser cowl, routed through engine mounted ducting, and discharged on the engine, LPT case. An engine mounted valve controls the LPT cooling air flow. The LPT and core compartment cooling air passes through the compartment and is discharged out of an annular opening between the fan thrust reverser and the core nozzle.
** ON A/C NOT FOR ALL The fan-compartment ram air scoop and vent ports are of a low pressure load flush design. The 4 core compartment air inlets are located in the core cowl and provide fan air to obtain the necessary cooling. LPT case cooling air also contributes to compartment ventilation. Fan discharge air is drawn through the LPT ram air scoop mounted on the thrust reverser cowl, routed through engine mounted ducting, and discharged on the engine, LPT case. An engine mounted valve controls the LPT cooling air flow. The LPT and core compartment cooling air passes through the compartment and is discharged out of an annular opening between the fan thrust reverser and the core nozzle.
3. Engine and Aircraft Accessory Cooling
The aircraft installation is designed to provide cooling and ventilation air for aircraft engine accessories mounted on the fan and core casing.
The distribution and circulation of the air in the compartments are such that the temperature limit for specific components is not exceeded.
The aircraft installation is designed to provide cooling and ventilation air for aircraft engine accessories mounted on the fan and core casing.
The distribution and circulation of the air in the compartments are such that the temperature limit for specific components is not exceeded.