Apu engine, Other Engineering

Assignment Help:

APU Engine

APU engines usually consist of a centrifugal compressor and a radial turbine however, axial compressors and turbines may be added or used in their own right. Centrifugal compressors are used because of their high compression and small size and when combined with a radial type turbine make the APU very compact. These components are also very robust and require less maintenance than axial flow components. Use is also made of reverse flow combustion chambers that again makes the overall size smaller.

220_APU engine.png

In most cases there is a design compromise made between the ideal APU for an aircraft i.e. its ability to provide air and electricity throughout the operational envelope of the aircraft, and it weight and size. It is usual therefore to find that air and electricity are limited to various altitudes dependant upon the parameter required.

APU systems are very basic and the APU will shut down if a problem is sensed. Most APU's will shut down for the following faults:

Fault

Comment

Low Oil Pressure

 

Engine Overspeed

110% Honeywell 108% Sundstrand

High EGT

849°C Honeywell

Loss of Speed Signal

Electronically monitored APU's need this signal to control the APU.

Los of EGT Signal

Electronically monitored APU's need this signal to control the APU.

Low Speed

Some APU's shutdown if they drop below 90%.

(Some will try and relight at 95%)

Electronic Unit Failure

Loss of Control

The APU may also shut down on the ground (not in flight) for the following faults:

Fault

Comment

 

Fire

May cause a warning horn in the u/c bay to sound

Generator Drive Low Oil Pressure or High Oil Temperature

 

 


Related Discussions:- Apu engine

Structural, what is covered un this field?

what is covered un this field?

Continuous casting, Continuous Casting : In essential, the process consist...

Continuous Casting : In essential, the process consists of pouring molten metal into a short vertical metal die or mould (at a controlled rate), which is open at both ends, coolin

Synchro resolvers for low load, Synchro resolvers for low load: Both tr...

Synchro resolvers for low load: Both transmitter and receiver rotors are energised by the same AC supply and will induce equal and opposing voltages in the stator coils provide

Communication and scholarship, Illustrate the importance of communication i...

Illustrate the importance of communication in a retail business organisation?25 marks

Rated breaking torque, Consider a 3-hp, 220-V, 1800-r/min separately excite...

Consider a 3-hp, 220-V, 1800-r/min separately excited dcmotor controlled by a single-phase fully controlled rectifierwith an ac source voltage of 230Vat 60Hz.Assume that the full-l

Testing of propellers, Testing After Install After installation of a pro...

Testing After Install After installation of a propeller, the engine must be ground run in order to check the propeller for correct function and operation.  Aircraft propeller in

Crystal symmetry, Q.   Define the crystal symmetry with reference to crys...

Q.   Define the crystal symmetry with reference to crystal structure. Ans.CRYSTAL SYMMETRY: A crystal is an orderly array of atoms in space. Atoms organize themselves in an

Engineering economy , A project has a first cost of $2000. There is another...

A project has a first cost of $2000. There is another cost at the end of year 1 of $500 and the income for year 3 until 6 year is $1000 per year. If the compounding is quarterly, c

Heat capacity, Specific heat capacity of water in a continues flow method?

Specific heat capacity of water in a continues flow method?

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd