The early jet engines based on a centrifugal compressor used a method of controlling fuel to the engine combustion chamber that used a _, a _ and a _.
fuel pump; relief valve; throttle valve
New developments such as the _ and _ created a demand for more complex methods of controlling airflow, fuel flow and exhaust gas flow.
axial compressor; reheat (afterburning)
What was the initial control system for early gas turbine engines?
Hydro-mechanical control systems
Early gas turbine control systems were initially entirely _.
hydro-mechanical
were developed to provide added functions such as temperature limiting and thrust management thus relieving the flight crew of this workload
supervisory controls/limited authority electronic trimmers
a major, high value item in any aircraft procurement programme
engine
In the case of a podded, under-wing engine as is common in commercial aircraft, where is the engine/airframe interface located?
between the engine and a nacelle
In fast jet military aircraft types, where is the engine/airframe interface located?
between the engine and the fuselage
enables the major project contractors to declare and agree their interfaces
interface control document (ICD)
What does the fuel control system regulate to prevent engine damage?
Rotating assembly speeds, rates of acceleration, and temperatures
In the _ engine, thrust is generated by imparting a relatively small increase in velocity to a very large air mass flow through the fan.
turbofan
In the older _ engines, the total air mass flow through the engine is much smaller and therefore, to achieve the same thrust, the velocity of the exhaust gasses must be much greater.
turbojet
Control is exercised over this aspect to allow varying engine speeds to be demanded and to allow the engine to be handled without damage by limiting rotating assembly speeds, rates of acceleration and temperatures.
fuel flow
Control is exercised over this aspect to allow the engine to be operated efficiently throughout the aircraft flight envelope and with adequate safety margins.
air flow
Control is exercised over this aspect by burning the exhaust gases and varying the nozzle area to provide additional thrust.
exhaust gas flow
Control of power or thrust is achieved by regulating the _ into the combustor.
fuel flow
On turbo jet or turbo fan engines, thrust can be controlled by setting an _.
engine pressure ratio
In the case of the larger commercial fan engines, thrust can be controlled by controlling _.
fan speed
On shaft power engines, the _ is a measure of the power delivered to the propeller or to the rotor.
speed of the gas generator
_ through the compressor may also be necessary by the use of variable vanes and/or bleed valves to provide adequate surge margin under all operating conditions.
Airflow modulation
a hydro-mechanical device mounted on the engine that contains valves to direct fuel and to restrict fuel flow, pneumatic capsules to modify flows according to prevailing atmospheric conditions, and dashpot/spring/damper combinations to control acceleration and deceleration rates
fuel control unit (FCU)/fuel management units (FMU)
In fuel flow control, _ must be avoided to reduce stresses in the rotating assemblies, and _ must be avoided to prevent blade damage and to reduce thermal creep.
overspeed; over temperature
Fuel is used as a cooling medium for oil by passing it through a _.
fuel cooled oil cooler (FCOC)
allows fuel flow to the engines to be modified to prevent an engine surge resulting from disturbance of the intake conditions from missile exhaust, shock from the gun muzzle or smoke from the gun breech
fuel dip
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Introduction to Avionics102
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Communication Systems41
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Navigation Systems68
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Flight Control Systems67
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Avionics Software and Hardware26
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Sensor Integration17
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Display Systems10
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Engine Control System40
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Pneumatic Systems41
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Testing and Validation Process8
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Certification and Standards45
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System Design and Development52
