Thrust indication - aircraft engine, Other Engineering

Assignment Help:

Thrust indication:

Although rpm gauges give an indication of the rotational speed of the compressor, they do have one drawback. They do not normally indicate the thrust output or power output of the engine. Any distress within a compressor may cause the engine to have a reduction in thrust output. Some means must be provided, therefore, to indicate the engine's power output. This is done by using an engine pressure ratio system, which is commonly known as EPR.

The system consists of pitot type pressure heads located in the engine inlet, which are averaged together and a series of pitot type pressure heads located at the turbine exhaust which are averaged together. Both feed into a pressure ratio transmitter. On a high bypass engine the sensed pressure at the rear of the engine can be the by pass or cold flow or a combined input from both the hot and cold flows.

The transmitter receives the pressure inputs from the inlet, and from the exhaust gas pressure probes. The probes are connected in to a common manifold, thus providing an average gas pressure. Both pressure tubes to the transmitter are provided with water drain traps that must be drained during maintenance checks.

The formula used by the transmitter in determining the EPR

signal is:- EPR = exhaust pressure/inlet pressure

Sometimes it can be expressed by using engine station configuration numbers, i.e. inlet PT2 or Exhaust PT7 (PT= pressure total), therefore EPR can be expressed as:-

PT7/PT2

As EPR is used as a thrust parameter, the flight crew must determine the maximum EPR for the barometric/temperature conditions. Take off EPR or maximum EPR can be determined by checking trim charts for engineers, or take off charts for flight crew. The EPR gauge in Fig. that there is an EPR set knob. Once the EPR target figure has been calculated, then by turning the knob 'a reference target bug can be set at the take off EPR setting. This indicates to the crew the maximum amount of EPR required. Exceeding this figure could possibly overboost the engine. Modern aircraft use aircraft sensors to make this correction and will set the bug for the pilot if required.

334_Thrust indication.png


Related Discussions:- Thrust indication - aircraft engine

Area and voume by contour, what do you know about area and volume by contou...

what do you know about area and volume by contour?explain

Fire protection project, the requirements are 1- prescriptive analysis of o...

the requirements are 1- prescriptive analysis of occupancy through prescriptive code analysis with in- depth information related to the egress.2- fire scenario design realistic and

Exhaust section inspection of aircraft, Exhaust Section Inspection. Ins...

Exhaust Section Inspection. Inspection of the exhaust section of the engine can be done visually using an appropriate light source. The exhaust cone and jet pipe are examined

Flight control - linear system, Representations of a linear system The ...

Representations of a linear system The linear system of Section is shown in block diagram To determine the responseof the output of the system y(t) to an input u(t) the initial

The compression after impact test, This Compression After Impact (CAI) test...

This Compression After Impact (CAI) test fixture was developed by the Boeing Company. The specimen, typically, but not necessarily, a quasi-isotropic laminate, is 6" long, 4" wide,

Pov display, require help in making pov display

require help in making pov display

#friction, the crate has a mass M and is subjectedto towing P acting at an ...

the crate has a mass M and is subjectedto towing P acting at an angle t1 with the horizontal.if the coefficient of static friction is k,determine the magnitude of p to just start

Case Let, This case has been framed in order to test the skills in evaluati...

This case has been framed in order to test the skills in evaluating a credit request and reaching a correct decision. Perluence International is large manufacturer of petroleum and

Java , why we need EJB

why we need EJB

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