Thrust indication - aircraft engine, Other Engineering

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

Posted Date: 9/12/2012 4:36:42 AM | Location : United States







Related Discussions:- Thrust indication - aircraft engine, Assignment Help, Ask Question on Thrust indication - aircraft engine, Get Answer, Expert's Help, Thrust indication - aircraft engine Discussions

Write discussion on Thrust indication - aircraft engine
Your posts are moderated
Related Questions
how to get guidance of projects in electrical engineering?

equivalent circuit of tunnel diode

Evolutionary Methods Optimization methods based upon natural or biological processes Need to be able to parameterise a solution and determine a cost function (good or bad

Q. Explain the mechanism for dislocation in plastic deformation. Ans.  Stresses are acting on dislocation in a crystal that is known as stress field, due to these stress forc

Fire fighting operations - high rise buildings: Inlets that allow the fire service to supplement to water to the sprinklers and to the fire mains are useful additions to the m

1. Briefly explain how to conduct a market segmentation analysis for an organization. Answer: There are a number of ways by which the market segmentation analysis of an organizatio

hardness of bore well water is less than sea water

routing sheet for rh shaft

Specify the inner-loop gain such that the damping coefficient of the closed loop is equal to 0.4

Fire alarm systems: Fire alarm systems can be very complex and it is usually not possible for an enforcing officer to check all the cabling, the components, the software and t