By far the greater part of our understanding about stall and surge in
axial compressors comes from work on low-speed laboratory machines. As
a general rule, these machines do not model the compressibility effec
ts present in high-speed compressors and therefore doubt has always ex
isted about the application of low-speed results to high-speed machine
s. In recent years interest in active control has led to a number of s
tudies of compressor stability in engine-type compressors. The instrum
entation used in these experiments has been sufficiently detailed that
, for the first time, adequate data are available to make direct compa
risons between high-speed and low-speed compressors. This paper presen
ts new data from an eight-stage fixed geometry engine compressor and c
ompares them with low-speed laboratory data. The results show remarkab
le similarities in both the stalling and surging behavior of the two m
achines, particularly when the engine compressor is run at intermediat
e speeds. The engine results also show that, as in the laboratory test
s, surge is precipitated by the onset of rotating stall. This is true
even at very high speeds where it had previously been thought that sur
ge might be the result of a blast wave moving through the compressor.
This paper therefore contains new information about high-speed compres
sors and confirms that low-speed testing is an effective means of obta
ining insight into the behavior of high-speed machines.