Embraer 175 / 195 Family – The APU Operation

The APS 2300 is an APU (Auxiliary Power Unit) that is manufactured by Pratt & Whitney in Canada.

As with any engine the airflow is the main focus to create power and follows the four principles of
Suck, Squeeze, Bang and Blow. The air will be drawn into then engine, then compressed, we add fuel and ignite it to create the bang, the high energy hot air is now expelled through a turbine which it drives and this is the blow.

The APU is a little different to the jet engine in that it has a specific function and essentially operates at one speed with a very small margin of adjustment.

The air inlet is located on the bottom of the APU.

The air inlet includes a perforated screen to
prevent ingestion of foreign objects into the engine.

The compressor section is connected aft of the air inlet housing. The compressor section includes the diffuser and the rotor assembly.

The engine is a continuous cycle engine that utilizes a centrifugal compressor impeller and two axial flow turbines that are connected by a common shaft.

The gearbox assembly is a one-piece housing which contains the reduction gears and oil pump. The lower part of the gearbox is used as an oil sump for the lubrication system.

The turbine section is connected to the compressor section and the combustor assembly.

The turbine section includes the turbine nozzles.
Why not learn more about the Embraer E170 and E 190 family on our General Familiarisation Course or take a look at some of our other courses www.oat.aero and be sure to follow us.