DOC AIRBUS | AMM A320FMIXED EXHAUST SYSTEM - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. General
The mixed exhaust system collects two flows of air. The first is the cold airflow, which is the fan bypass air. The second is the hot airflow which comes from the engine core.
The mixed exhaust system is made up of the common nozzle exhaust collector and the engine exhaust cone.
** ON A/C NOT FOR ALL The mixed exhaust system collects two flows of air. The first is the cold airflow, which is the fan bypass air. The second is the hot airflow which comes from the engine core.
The mixed exhaust system is made up of the common nozzle exhaust collector and the engine exhaust cone.
- The common exhaust collector admits the hot and cold gas outflows. These gas outflows then go out to the atmosphere through the common nozzle.
The nozzle forms a convergent duct which increases the speed of the mixed gas to give forward thrust. - The engine exhaust cone forms the inner contour of the common nozzle exhaust collector. It is made of a welded inco 625 honeycomb perforated panel for sound attenuation, an attachment ring and a closure panel.
The cold airflow exhaust is part of the thrust reverser system described in 78-30-00. When the thrust reverser operates, the cold and hot outflows divide, and go in different directions.
2. Description
Mixed Exhaust SystemA. Common nozzle exhaust collector
(1) The common nozzle exhaust collector is made up of an inner duct with four radial struts. These struts support an outer duct. The unit is installed on the outer rear flange of the engine turbine case.
(2) The inner duct forms a ring around the core outlet nozzle. The front flange of the duct is used to install the exhaust collector to the outer rear turbine case flange.
The inner duct (hot nozzle) is provided with accoustical treatment.
The inner duct (hot nozzle) is provided with accoustical treatment.
(3) Four support struts, positioned radially around the inner duct, hold the exhaust collector outer duct assembly. Two side struts are positioned horizontally and are riveted on either side of the inner duct. Each of the struts is attached to the outer duct by two bolts and captive nuts.
(4) The lower center strut lines up with the vertical center line. It is riveted to the inner duct. The strut is attached to the outer duct by eight bolts with captive self-locking nuts.
(5) At the top center position, an upper strut assembly straddles the inner duct across the vertical center line. It is riveted to the inner duct and to the outer duct.
(6) The collector outer duct is made up of a conical duct to which a sheet metal forward fairing is riveted. The leading edge of the fairing is against the rear of the cold airflow thrust reverser case. The translating cowl trailing edge overlaps the outer duct leading edge.
A vectored exhaust nozzle has been incorporated on the CNA.
A vectored exhaust nozzle has been incorporated on the CNA.
(7) A common nozzle fairing is attached to the rear of the upper support strut and to the inside of the outer duct along its upper edge. The fairing tapers to a pen nib profile at its trailing edge. This gives a streamlined profile for the cold stream air which enters the collector.
(8) Interface seals provide sealing between the exhaust collector, the thrust reverser and the pylon (Ref. para.3).
3. Interface Sealing
Seals are installed around the front of the inner duct and upper and lower support struts. They seal the inner duct with the thrust reverser C-ducts.
These seals are made in sections to suit the directional changes in the seal run.
A circumferential seal is installed around the outside of the forward section of the exhaust collector. This seal gives an interface seal between the collector and the rear edge of the translating cowl. It prevents leakage of fan air to ambient during forward thrust operation.
Block seals are attached to the left and right front corners of the upper support strut. They complete the seal between the aircraft pylon, the C-ducts, the upper strut and the outer duct seals.
Seals are installed around the front of the inner duct and upper and lower support struts. They seal the inner duct with the thrust reverser C-ducts.
These seals are made in sections to suit the directional changes in the seal run.
A circumferential seal is installed around the outside of the forward section of the exhaust collector. This seal gives an interface seal between the collector and the rear edge of the translating cowl. It prevents leakage of fan air to ambient during forward thrust operation.
Block seals are attached to the left and right front corners of the upper support strut. They complete the seal between the aircraft pylon, the C-ducts, the upper strut and the outer duct seals.