Electronic engine control systems - aircraft engine, Other Engineering

Electronic engine control systems :

Advances in gas turbine technology have demanded more precise control of engine parameters than can be provided by hydromechanical fuel controls alone. These demands are met by electronic engine controls, or EEC, of which there are two types: supervisory and full-authority.

SUPERVISORY ELECTRONIC ENGINE CONTROL

The first type of EEC is a supervisory control that works with a proven hydromechanical fuel control.
The major components in the supervisory control system include the electronic control itself, the hydromechanical fuel control on the engine, and the bleed air and variable stator vane control. The hydromechanical element controls the basic operation of the engine including starting, acceleration, deceleration, and shutdown. High-pressure rotor speed (N2), compressor stator vane angles, and engine bleed system are also controlled hydromechanically. The EEC, acting in a supervisory capacity, modulates the engine fuel flow to maintain the designated thrust. The pilot simply moves the throttle lever to a desired thrust setting position such as full takeoff thrust, or maximum climb. The EEC adjusts the fuel flow as required to maintain the thrust compensating for changes in flight and environmental conditions. The EEC control also limits engine operating speed and temperature, ensuring safe operation throughout the flight envelope.
If a problem develops, control automatically reverts to the hydrome¬chanical system, with no discontinuity in thrust. A warning signal is displayed in the cockpit, but no immediate action is required by the pilot. The pilot can also revert to the hydromechanical control at any time.
Electronic Engine Control

A typical example of an EEC system is that used in many of the Pratt and Whitney 100 series engines currently in service. A brief explanation of how the system works, both in automatic and manual modes follows.

146_electronics engine control system.png

Automatic Operation (EEC mode)

The EEC receives signals from various sources:
a. Power Management Switch, enabling take off thrust, maximum continuous thrust, climb thrust or cruise thrust settings to be selected.
b. Engine inlet pressure and temperature.
c. Ambient pressure.
d. Air data computer inputs. (a computer that senses pitot pressure, static pressure and total air temperature)
e. Engine RPMs - N1 and N2.
f. Power lever position. (via a potentiometer)
g. Failure signals.

Based on these input signals the EEC will output command signals to adjust and control:

a. The Hydromechanical Fuel Control Unit via a stepper motor which adjusts the throttle metering valve.
b. Ignition circuits.
c. Bleed valves
d. Torque gauge

 

Posted Date: 9/12/2012 3:32:08 AM | Location : United States







Related Discussions:- Electronic engine control systems - aircraft engine, Assignment Help, Ask Question on Electronic engine control systems - aircraft engine, Get Answer, Expert's Help, Electronic engine control systems - aircraft engine Discussions

Write discussion on Electronic engine control systems - aircraft engine
Your posts are moderated
Related Questions
Expertsmind.com offers Performing Numeric Computation matlab assignment help MATLAB contains numbers, precise, and technological innovation features to support all common tech

Capital Rationing Capital Rationing refers to a situation where the firm is constrained for external, or self-imposed, reasons to obtain necessary funds to invest in all investmen

apply equations to solve problems for specified aerodynamic applications. Need some inputs regarding this.

Static stability derivatives Static stability requires that a restoring action to any motions caused by forces and moments is auto-matically produced along and about the same a

write drawback of linear array

ENGINE TORQUE It is the force of rotating action about the crankshaft axis at any given instant of time. It is given by,

difference between inline code and code behind file in asp.net

tunnel diode

what are clippers

Please explain how risk is taken into account for a financial instrument