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

Elastic and plastic deformation, Q. Define elastic and plastic deformation ...

Q. Define elastic and plastic deformation and differentiate between them. Ans. Elastic deformation : Elastic deformation is that part of the deformed material, when the

Enhancement mode mosfet, ENHANCEMENT MODE MOSFET In the enhancement-mod...

ENHANCEMENT MODE MOSFET In the enhancement-mode type, the gate must be forward biased to produce charge carriers in the channel. These devices are normally of and do not condu

Torsional divergence, Torsional Divergence Lets first try to explain a...

Torsional Divergence Lets first try to explain and interpret torsional divergence for the aerofoil structural model physically. An additional figure describing the mechanical s

Principles of sprinkler systems-fire safety engineering, Principles of Spri...

Principles of Sprinkler Systems-Fire safety Engineering Sprinkler systems may be installed in a building to achieve a number of different objectives.  Very often the primary r

Variable interest rate, What is Variable Interest Rate? Interest rates whic...

What is Variable Interest Rate? Interest rates which is offered by banks or financial institutions on loans or deposits which are liable to change according to circumstances. For e

Mining, Students are to undertake a tunnel blast design for the following c...

Students are to undertake a tunnel blast design for the following conditions: • Tunnel is 5.5m wide by 5.5.m high • Rock is a granite with a UCS of 300 MPa • Drill hole diameter is

International finance, at the beginning of year 1 the terranian central ban...

at the beginning of year 1 the terranian central bank conducted k100 million of dollar selling/terranian kwacha buying intervention. The intervention was undertaken at the rate of

Case study, dhpl is the firm situated in faridabad,its ending year on 31st ...

dhpl is the firm situated in faridabad,its ending year on 31st march 2009 ,1000million asset base rs.650 million & the net profit of the company was 76 milloin the managmnt of the

Double acting feathering system, Double acting feathering system: To pr...

Double acting feathering system: To prevent excessive drag in the event of a propeller on engine failure, the double acting propeller as with the single acting propeller requir

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