Measurements on compressor dynamic total pressure with dynamic correction of pneumatic probe

The pressure signals at measurement points are extracted via pneumatic probes and restored by dynamic correction in order to obtain the multi-point dynamic total pressures in the compressor conveniently and safely. The discrete transfer function models are used to correct the measured signals and obtain the real pressures at the measurement points. These models are identified by the downward step input signals and probe response output signals generated by the burst balloon device. It is proved that the method is reliable for the signal dynamic correction within 1000Hz, the phase delay can be eliminated virtually and the tube resonance effect on the signal amplification can be reduced obviously after correction of the probe signal. The measurement results of dynamic total pressure in compressor show that the signal amplitude of blade passing frequency at rotor inlet increases gradually with the decrease of mass flow rate, meanwhile, the broadband disturbance intensity at stator outlet increases and reaches the maximum at the near rotating stall point. In addition, the spike-type rotating stall inception first appears near the tip of the rotor blade leading edge, then expands rapidly to the blade root and develops into a full-span rotating stall cell. The propagation speed of the fully developed stall cell is about 30% of the rotor rotating speed.