The identification of compressors’ pre-surge effects for use in an adaptive gas-turbine engine control system
The problem of aircraft gas-turbine engine automatic control, adapted to the boundaries of the engines’ stability, is studied. The experimental investigation on the unsteady processes in eight stages high speed axial compressor have been carried out. By using fast response pressure transducers instrumented on the rotor casing, the pressure time series were acquired at different operation points from throttle open (normal operation) to surge point. The objective of this investigation is to obtain information about flow behavior in supersonic stage of the compressor at different operation points and to form an pre-surge criterion. The criterion could be used in adaptive engine control system (ACS GTE). For this purpose the band-pass filter is proposed and developed. The band-pass filter is based on a combination of recursive high and low pass filters with an infinite impulse response. Carried out seminatural experiment on filtration algorithms at the stability limit showed the effectiveness of the developed identification criterion for detection of pressure fluctuations peak under the shoulder blade, characterizing the pre-surge modes of the compressors’ operation. The proposed expansion of the ACS GTE functions will significantly increase the reliability of the engine and flight safety.