To execute online warning and active control for aerodynamic instability of compressors, aerodynamic instability inception must be detected accurately and timely. Computation and analysis variance of outlet total pressure signal around loosing compressor aerodynamic stability of certain engine, and corresponding analysis results demonstrate that the variance has evidently increased and the method can detect inception signal of aer- odynamic instability of the compressor 0.04 s in advance. Besides, an improved variance method on the basis of variance method is proposed. The improved method detects inception signal 0.07 s earlier than the variance. For the advantages of less in engineering practice to operation and high computing speed, the improved variance algorithm can be applied achieve real-time active control for aerodynamic instability of compressors.
Measurement ＆ Control Technology
improved variance method