Mm. Bright et al., STALL PRECURSOR IDENTIFICATION IN HIGH-SPEED COMPRESSOR STAGES USING CHAOTIC TIME-SERIES ANALYSIS-METHODS, Journal of turbomachinery, 119(3), 1997, pp. 491-499
This paper presents a new technique for precursor identification in hi
gh-speed compressors. The technique is a pseudo-correlation integral m
ethod referred to as the correlation method. To provide a basis for co
mparison, the traveling wave energy technique, which has been used ext
ensively to study prestall data, is also briefly presented and applied
The correlation method has a potential advantage over the traveling w
ave energy method because it uses a single sensor for detection. It al
so requires no predisposition about the expected behavior of the data
to detect ''changes'' in the behavior of the compressor. Both methods
are used in this study to identify stall precursive events in the pres
sure fluctuations measured from circumferential pressure transducers l
ocated at the front face of the compressor rig. The correlation method
successfully identified stall formation or changes in the compressor
dynamics from data captured from four different configurations of a NA
SA Lewis single-stage high-speed compressor while it was transitioned
from stable operation into stall. This paper includes an exposition on
the use of nonlinear methods to identify stall precursors, a descript
ion of the methodologies used for the study, information on the NASA h
igh-speed compressor rig and experimental data acquisition, and result
s from the four compressor configurations. The experimental results in
dicate that the correlation method provides ample warning of the onset
of rotating stall at high speed, in some tests on the order of 2000 r
otor revolutions. Complementary features of the correlation method and
the traveling wave energy method are discussed, and suggestions for f
uture developments are made.