Fluidics in Aircraft Engine Controls

Fluidics is a particularly appropriate technology for engine controls as it is capable of measuring pressure ratio, one of the basic engine performance parameters, as a fundamental quantity. This results in improved accuracy of measurement and obviates the need of conventional systems to utilize nonoptimum, but easier to measure, control parameters. A wide range of aircraft engine controls has been developed covering controls for compressor inlet guide vanes, compressor bleed valves, engine fuel flow including engine instrumentation. Total fluidic unit deliveries exceed 4200 and the civil operating hours exceed 13.5 million. As a further development, a completely fluidic engine control system is proposed with an electronic computer controlled secondary control or trim system for efficiency optimization.