Electronic Systems and Computer Technology - Decreasing Fuel Consumption and Exhaust Gas Emissions in Transportation - page 99

6.3.2 Engine Monitoring System
A turbofan engine consists of two mechanically independent rotors [ 24 ]. One rotor
operates inside the other. The main elements are:
• Fan;
• Low pressure compressor;
• Low pressure turbine installed on the inner rotor called N1 rotor; and
• Outer rotor called N2 that holds the high pressure compressor and high pressure
turbine.
The engine fuel and oil system include:
• Valve for passing the fuel to the engine;
• Pump to increase fuel pressure;
• Fuel and an oil cooler and heater;
• Fuel filter;
• Pump to further increase fuel pressure;
• Shut off valve before the combustion chamber; and
• Fuel flow meter providing flow information to the FMS.
The basic parameters of the engine are:
• N1 and N2 rotation speeds;
• Exhaust Gas Temperature;
• Oil pressure, oil temperature, and oil quantity;
• Fuel flow and filter saturation;
• Engine vibration;
• Fuel valve position; and
• Engine failure alert indication.
Theoretically measurement devices for combustion products and exhaust gas
substances can be installed in two zones (see Fig. 6.4 )[ 25 ].
Measuring parameters are indicated and displayed in the cockpit, and compared
with their operating and calculated ranges.
The mechanical or electronic engine control system senses the position of the
thrust lever, and compares actual and target N1 to the aircraft's configuration and
altitude. It automatically sets engine thrust by adjusting the fuel flow to achieve the
target N1, controlled by the auto throttle system or by the pilot.
6.3.3 Airplane Instruments
Flight instruments give information to the pilot about the aircraft's speed, direction,
altitude, present position, and spatial orientation. Power plant instruments provide
data about the status of the aircraft's engines and the APU. System instruments give