An early warning method for axial compressor rotating stall based on frequency domain hump recognition

Abstract

The invention discloses an axial flow compressor rotating stall early warning method based on frequency-domain hump identification. The method continuously calculates the frequency spectrum of the pressure signal within a compressor rotation cycle through continuous dynamic pressure signal collection and fast Fourier transform. The characteristic hump discriminant factor Ch corresponding to the frequency spectrum is calculated, and by comparing the characteristic hump discriminant factor Ch with the detection threshold Chstall, it is judged whether the compressor is close to the rotating stall boundary. The characteristic hump discriminant factor Ch defined by the axial flow compressor rotating stall early warning method has a clear physical meaning, and is used for real-time on-line detection of the frequency domain hump that occurs prior to the rotating stall, so that when the working condition of the compressor is close to the boundary of the rotating stall, it will send out Early warning, early warning method is reliable. The axial compressor rotating stall early warning method only needs a single signal sensor, adopts fast Fourier transform, has few intermediate processes and fast calculation speed, and provides sufficient response time for active control.

Description

technical field [0001] The invention relates to the technical field of turbomachinery stability expansion, in particular to a method for early warning of rotational stall of an axial flow compressor based on hump identification in the frequency domain. Background technique [0002] Rotating stall is a common aerodynamic instability phenomenon in compressors, which can lead to a sharp deterioration in compressor performance, or lead to blade breakage and damage to the entire compressor. The traditional stall control method is a passive control technology, and its core is to ensure that there is sufficient margin between the operating point of the compressor and the stall boundary, so that the compressor can work far away from the stall boundary point. However, the stall boundary is often affected by factors such as the working state and the distortion of the inlet flow field, so it is difficult to determine accurately. The stall point often appears near the highest pressure r...

AI Technical Summary

Problems solved by technology

This situation makes it difficult for the actuation system to have enough time to respond, making it difficult for the stability active control technology based on the prediction of stall precursors to be practically applied in aero-engines

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