Analysis and Characteristics of Compressor Stall Precursor Signals in Forward and AFT Swept High Speed Compressor.

摘要

The stall characteristic of four single-stage transonic compressor rotors were investigated as they were throttled to stall. Forward-swept, backward-swept, and straight leading edge rotors were examined. Three methods of analysis (1) windowed power spectrum densities of pressure and spatial Fourier coefficients, (2) phase tracking analysis, and (3) system identification were used to identify the first appearance of modal waves and their accompanying frequencies in order to identify a stall warning time. A direct correlation between the amount of stall warning time and the shape of the compressor characteristic was found. Specifically, if the compressor characteristic had a significant period of flat or positive slope, more stall warning was noted. It was also found that the forward-swept rotor consistently provided more stall warning time than the backward-swept and straight leading edge rotors. Compressors, axial compressor, compressor stall, stall inception, compressor stability, stall warning, transonic compressor, forward-swept compressor, aft-swept compressor.