Zs. Spakovszky et al., Rotating stall control in a high-speed stage with inlet distortion: Part II - Circumferential distortion, J TURBOMACH, 121(3), 1999, pp. 517-524
Citations number
21
Categorie Soggetti
Mechanical Engineering
Journal title
JOURNAL OF TURBOMACHINERY-TRANSACTIONS OF THE ASME
This paper presents the first attempt to stabilize rotating stall in a sing
le-stage transonic axial flow compressor with inlet distortion using active
feedback control. The experiments were conducted at the NASA Lewis Researc
h Center on a single-stage transonic core compressor inlet stage. Art array
of 12 jet injectors located upstream of the compressor was used for forced
response testing and feedback stabilization. Results for a circumferential
total pressure distortion of about one dynamic head and a 120 deg extent (
DC(60) = 0.61) are reported in this paper. part I (Spakovszky et al., 1999)
reports results for radial distortion. Control laws were designed using em
pirical transfer function estimates determined from forced response results
. Distortion introduces coupling between the harmonics of circumferential p
ressure perturbations, requiring multivariable identification and control d
esign techniques. The compressor response displayed a strong first spatial
harmonic, dominated by the well-known incompressible Moore-Greitzer mode. S
teady axisymmetric injection of 4 percent of the compressor mass flow resul
ted in a 6.2 percent reduction of stalling mass flow. Constant gain feedbac
k, using unsteady asymmetric injection yielded a further range extension of
9 percent. A more sophisticated robust H-infinity controller allowed a red
uction in stalling mass flow of 10.2 percent relative to steady injection,
yielding a total reduction in stalling mass flow of 16.4 percent.