This paper describes the first experimental validation of transfer function modeling and active stabilization for axial compressors with circumferential inlet distortion. The inlet distortion experiments were carried out in a three-stage low-speed compressor. Theory–experiment comparisons of steady performance, unsteady stall precursor, and forced response (transfer function) data were all used to assess a control-theoretic version of the Hynes–Greitzer distorted flow model. The tests showed good agreement between theory and data and demonstrated that a priori predictions, based on geometry and steady-state performance data, can be used to design control laws that stabilize rotating stall with inlet distortion. Based on these results, active feedback control has been used to stabilize the inlet distortion induced instability associated with rotating stall onset. The stabilization allowed stall-free operation to be extended below the natural (distorted flow) stall point by up to 3.7 percent for a 0.8 dynamic head distortion. For a 1.9 dynamic head distortion, 40 percent of the mass flow range lost due to inlet distortion was regained through active control. The paper elucidates the difficulties associated with active control with distortion, and introduces a new control law that addresses many of these challenges.

1.
F. Aulehla and D. M. Schmitz, “New Trends in Intake/Engine Compatibility Assessment,” in: AGARD-CP-400: Engine Response to Distorted Inflow Conditions, Mar. 1987.
2.
Chue
R.
,
Hynes
T. P.
,
Greitzer
E. M.
,
Tan
C. S.
, and
Longley
J. P.
, “
Calculation of Inlet Distortion Induced Compressor Flow Field Instability
,”
International Journal of Heat and Fluid Flow
,
10
(
3
):
211
233
, Sept.
1986
.
3.
J. S. Freudenberg and D. P. Looze, “Right Half Plane Poles and Zeros and Design Tradeoffs in Feedback Systems,” IEEE Transactions on Automatic Control, 30(6), June 1985.
4.
E. M. Greitzer, A. H. Epstein, G. R. Guenette, D. L. Gysling, J. Haynes, G. J. Hendricks, J. D. Paduano, J. S. Simon, and L. Valavani, “Dynamic Control of Aerodynamic Instabilities in Gas Turbine Engines,” Steady and Transient Performance Prediction of Gas Turbine Engines, AGARD-LS-183, pp. 8-1–8-21, May 1992.
5.
G. Gu, S. Banda, and A. Sparks, “An Overview of Rotating Stall and Surge Control for Axial Flow Compressors,” Technical report, Wright-Patterson, Nov. 1995; private communication.
6.
J. M. Haynes, “Active Control of Rotating Stall in a Three-Stage Axial Compressor,” Master’s thesis, Department of Aeronautics and Astronautics, MIT, 1993.
7.
Haynes
J. M.
,
Hendricks
G. J.
, and
Epstein
A. H.
, “
Active Stabilization of Rotating Stall in a Three-Stage Axial Compressor
,”
ASME JOURNAL OF TURBOMACHINERY
,
116
:
226
239
,
1994
.
8.
Hynes
T. P.
and
Greitzer
E. M.
, “
A Method for Assessing Effects of Circumferential Flow Distortion on Compressor Stability
,”
ASME JOURNAL OF TURBOMACHINERY
,
109
:
371
379
, July
1987
.
9.
H. Kwakernaak and R. Sivan, Linear Optimal Control Systems, Wiley-Interscience, 1972.
10.
P. L. Lavrich, “Time Resolved Measurements of Rotating Stall in Axial Flow Compressors,” PhD thesis, Department of Aeronautics and Astronautics, MIT, Aug. 1988; also available as Gas Turbine Lab Report #194.
11.
J. P. Longley, “Inlet Distortion and Compressor Stability,” PhD thesis, Trinity College, Cambridge University, 1988.
12.
Longley
J. P.
, “
A Review of Nonsteady Flow Models for Compressor Stability
,”
ASME JOURNAL OF TURBOMACHINERY
,
116
:
202
215
, Apr.
1994
.
13.
J. P. Longley and E. M. Greitzer, “Inlet Distortion Effects in Aircraft Propulsion System Integration,” Steady and Transient Performance Prediction of Gas Turbine Engines, AGARD-LS-183, pp. 6-1–6-18, May 1992.
14.
Moore
F. K.
, “
A Theory of Rotating Stall of Multistage Axial Compressors: Part I—Small Disturbances
,”
ASME Journal of Engineering for Gas Turbines and Power
,
106
:
313
320
, Apr.
1984
.
15.
Moore
F. K.
, “
A Theory of Rotating Stall of Multistage Axial Compressors: Part II—Finite Disturbances
,”
ASME Journal of Engineering for Gas Turbines and Power
,
106
:
321
326
, Apr.
1984
.
16.
Moore
F. K.
and
Greitzer
E. M.
, “
A Theory of Post-Stall Transients in Axial Compressors: Part I—Development of the Equations
,”
ASME Journal of Engineering for Gas Turbines and Power
,
108
:
68
76
,
1986
.
17.
Paduano
J. D.
,
Epstein
A. H.
,
Valavani
L.
,
Longley
J. P.
,
Greitzer
E. M.
, and
Guenette
G. R.
, “
Active Control of Rotating Stall in a Low-Speed Axial Compressors
,”
ASME JOURNAL OF TURBOMACHINERY
,
115
:
48
56
, Jan.
1993
.
18.
C. Reid, “The Response of Axial Flow Compressors to Intake Flow Distortion,” ASME Paper No. 69-GT-29, 1969.
19.
Tryfonidis
M.
,
Etchevers
O.
,
Paduano
J. D.
,
Epstein
A. E.
, and
Hendricks
G. J.
, “
Pre-stall Behavior of Several High-Speed Compressors
,”
ASME JOURNAL OF TURBOMACHINERY
, Vol.
117
,
1995
, pp.
62
80
.
20.
C. M. van Schalkwyk, “Active Control of Rotating Stall With Inlet Distortion,” PhD thesis, Department of Aeronautics and Astronautics, MIT, June 1996; also available as Gas Turbine Lab Report #222.
21.
D. D. Williams, “Engine Compatibility,” Technical report, Rolls-Royce PLC, May 1991.
This content is only available via PDF.
You do not currently have access to this content.