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Does APU provide any thrust?
Hiding inside the tail of most every airliner is an extra engine called an Auxiliary Power Unit or APU. Unlike the aircraft’s main engines, the APU outputs almost no thrust. Most of the power produced is used to run an electric generator and provide pneumatic (air) pressure.
How much thrust does an APU produce?
APU – The little turbine engine However, unlike the main engines, the APU does not provide thrust (hence it would be wrong to call it a jet engine). Instead, it powers an electric generator and provides air pressure. Why have this extra engine when you already have two or four much larger ones?
How much power does an APU produce?
APU Power Requirements of Major Aircraft Classes The output power range of APUs is between 10 kW and 300 kW, with bleed supplied requiring additional turbine power.
How do engines produce thrust?
Jets or rocket engines produce thrust by increasing the pressure inside the engine. The exhaust gases produced by a propeller, jet or rocket, due to Newton’s Third Law, are feeling a force opposite and equal to the thrust, and therefore are moved in the direction opposite to the thrust of the engine.
Does thrust increase with altitude?
Since higher air-speeds are normally used at higher altitudes, thrust generally decreases with an aircraft’s altitude. But increasing altitudes can erode thrust because the mass of air being consumed is also decreasing as the air gets increasingly more rarified.
Do helicopters have APU?
The auxiliary power unit (APU) is used to start the main engines and for pre-flight preparation of helicopters and aeroplanes. During flight, it serves as an auxiliary source of power if the main engine fails. After start-up, they generate electrical power to the main on-board systems during pre-flight preparation.
Can an APU be re-purposed as a thrust nozzle?
The amount of thrust available from an APU would be minuscule as it is designed drive various aircraft systems and adding on a nozzling system geared for propulsion would reduce the power available for doing it’s intended work. Even if an APU was re-purposed for propulsion, it most likely would not be enough to have any significant role.
What is the purpose of the APU in an engine?
It is an issue of power (as well as having that power effectively converted to thrust). The APU is designed to provide electrical, bleed air (for environmental control, and for starting other engines), and in some cases they may run other accessories.
Why can’t we use APU’s to maintain level flight?
Practically speaking, APUs are not sufficiently powerful to provide the thrust necessary to maintain level flight. It is an issue of power (as well as having that power effectively converted to thrust).
Is there any exhaust gas from the APU?
For your question, there is exhaust gas from the APU but its very minimal or not powerful enough to provide any forward thrust. APU is normally used on the ground if there are no GPUs to provide electrical power for lighting and instruments, provide pneumatic power for Air Conditioning and for starter to start engines.