A three-stage, low-speed axial research compressor has been actively s
tabilized by damping low-amplitude circumferentially traveling waves,
which can grow into rotating stall. Using a circumferential array of h
ot- wire sensors, and an array of high-speed individually positioned c
ontrol vanes as the actuator, the first and second spatial harmonics o
f the compressor were stabilized down to a characteristic slope of 0.9
, yielding an 8 percent increase in operating flow range. Stabilizatio
n of the third spatial harmonic did not alter the stalling flow coeffi
cient. The actuators were also used open loop to determine the forced
response behavior of the compressor. A system identification procedure
applied to the forced response data then yielded the compressor trans
fer function. The Moore-Greitzer two-dimensional stability model was m
odified as suggested by the measurements to include the effect of blad
e row time lags on the compressor dynamics. This modified Moore-Greitz
er model was then used to predict both the open and closed-loop dynami
c response of the compressor. The model predictions agreed closely wit
h the experimental results. In particular, the model predicted both th
e mass flow at stall without control and the design parameters needed
by, and the range extension realized from, active control.