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Podded engine
A podded engine is a jet engine that has been built up and integrated in its nacelle. This may be done in a podding facility as part of an aircraft assembly process. The nacelle contains the engine, engine mounts and parts which are required to run the engine in the aircraft, known as the EBU (Engine Build Up). The nacelle consists of an inlet, an exhaust nozzle and a cowling which opens for access to the engine accessories and external tubing. The exhaust nozzle may include a thrust reverser. The podded engine is a complete powerplant, or propulsion system, and is usually attached below the wing on large aircraft like commercial airliners or to the rear fuselage on smaller aircraft such as business jets.
The EBU components connect the engine systems with the aircraft systems. Engine build up includes installation of an engine starter, hydraulic pumps, electrical generators and firewire and components which connect the engine to the aircraft. They include the following
A nacelle is a streamlined covering for a jet engine which incorporates the air inlet and exhaust outlet for the engine. The inlet is connected to a mounting flange on the front of the engine fan case. The exhaust nozzle, which may incorporate a thrust reverser, is connected to a mounting flange on the rear of the engine exhaust case. A cowling, streamlined between the inlet and exhaust, completes the nacelle. It has opening doors which allow access for regular maintenance such as adding oil as well as unscheduled replacement of engine accessories and external tubing.
How well the engine performs depends on the nacelle design. The shape of the lip on the inlet, the minimum internal area and the internal profile, are established with different engine airflows at cruise to keep pressure losses acceptable, and different incident airflow angles such as in cross-winds and during take-off rotation to keep variations in pressure across the fan face acceptable. Pressure losses, and hence overall pressure ratio, affect engine performance or fuel consumption for each pound of thrust. Pressure variations affect engine operability or likelihood of surging. Pressure losses in the exhaust nozzle also affect the engine performance by increasing the fuel consumption.
The nacelle forms the outer flow path along the engine to ensure accessories operate within their temperature limits and fire extinguisher flows are effective.
Placing engines on the wing provides beneficial wing bending relief in flight. The further the engines are away from the fuselage the greater the wing bending relief, therefore engines mounted close to the fuselage (in the wing root) provide little relief. Almost all modern large jet airplanes use engines in pods located a significant distance from the wing root for substantial wing bending relief. The pods are in front of the wing to help avoid flutter of the wing which, in turn, allows a much lighter wing structure.
An early example of fuselage mounting, the Junkers Ju 287, had two of its four engines mounted on the front fuselage. The same position was used for two of the three engines on the Martin XB-51.
Smaller jet airplanes like the Cessna Citation are generally not suited to podded engines below the wing because this would place the engines too close to the ground. This is also the case with aircraft designed to operate from unimproved grass or gravel runways. Instead, in these cases it is common to mount two (or occasionally four) podded engines on the rear of the fuselage, where they are less likely to be damaged by ingesting foreign objects from the ground.
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Podded engine AI simulator
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Podded engine
A podded engine is a jet engine that has been built up and integrated in its nacelle. This may be done in a podding facility as part of an aircraft assembly process. The nacelle contains the engine, engine mounts and parts which are required to run the engine in the aircraft, known as the EBU (Engine Build Up). The nacelle consists of an inlet, an exhaust nozzle and a cowling which opens for access to the engine accessories and external tubing. The exhaust nozzle may include a thrust reverser. The podded engine is a complete powerplant, or propulsion system, and is usually attached below the wing on large aircraft like commercial airliners or to the rear fuselage on smaller aircraft such as business jets.
The EBU components connect the engine systems with the aircraft systems. Engine build up includes installation of an engine starter, hydraulic pumps, electrical generators and firewire and components which connect the engine to the aircraft. They include the following
A nacelle is a streamlined covering for a jet engine which incorporates the air inlet and exhaust outlet for the engine. The inlet is connected to a mounting flange on the front of the engine fan case. The exhaust nozzle, which may incorporate a thrust reverser, is connected to a mounting flange on the rear of the engine exhaust case. A cowling, streamlined between the inlet and exhaust, completes the nacelle. It has opening doors which allow access for regular maintenance such as adding oil as well as unscheduled replacement of engine accessories and external tubing.
How well the engine performs depends on the nacelle design. The shape of the lip on the inlet, the minimum internal area and the internal profile, are established with different engine airflows at cruise to keep pressure losses acceptable, and different incident airflow angles such as in cross-winds and during take-off rotation to keep variations in pressure across the fan face acceptable. Pressure losses, and hence overall pressure ratio, affect engine performance or fuel consumption for each pound of thrust. Pressure variations affect engine operability or likelihood of surging. Pressure losses in the exhaust nozzle also affect the engine performance by increasing the fuel consumption.
The nacelle forms the outer flow path along the engine to ensure accessories operate within their temperature limits and fire extinguisher flows are effective.
Placing engines on the wing provides beneficial wing bending relief in flight. The further the engines are away from the fuselage the greater the wing bending relief, therefore engines mounted close to the fuselage (in the wing root) provide little relief. Almost all modern large jet airplanes use engines in pods located a significant distance from the wing root for substantial wing bending relief. The pods are in front of the wing to help avoid flutter of the wing which, in turn, allows a much lighter wing structure.
An early example of fuselage mounting, the Junkers Ju 287, had two of its four engines mounted on the front fuselage. The same position was used for two of the three engines on the Martin XB-51.
Smaller jet airplanes like the Cessna Citation are generally not suited to podded engines below the wing because this would place the engines too close to the ground. This is also the case with aircraft designed to operate from unimproved grass or gravel runways. Instead, in these cases it is common to mount two (or occasionally four) podded engines on the rear of the fuselage, where they are less likely to be damaged by ingesting foreign objects from the ground.