At low mass flow rates, axial compressors suffer from flow instabilities leading to stall and surge. The inception process of these instabilities has been widely researched in the past---primarily with the aim of predicting or averting stall onset. In recent times, attention has shifted to conditions well before stall and has focused on the level of irregularity in the blade passing signature in the rotor tip region. In general, the irregularity increases in intensity as the flow rate through the compressor is reduced. Attempts have been made to develop stall warning/avoidance procedures based on the level of flow irregularity, but little effort has been made to characterize the irregularity itself, or to understand its underlying cause. Work on this project has revealed for the first time that the increase in irregularity in the blade passing signature is highly dependent on both tip-clearance size and eccentricity. In a compressor with small, uniform, tip-clearance, the increase in blade passing irregularity that accompanies a reduction in flow rate will be modest. If the tip-clearance is enlarged, however, there will be a sharp rise in irregularity at all circumferential locations. In a compressor with eccentric tip-clearance, the increase in irregularity will only occur in the part of the annulus where the tip-clearance is largest, regardless of the average clearance level. In this paper, some attention is also given to the question of whether the irregularity observed in the prestall flow field is due to random turbulence or to some form of coherent flow structure. Detailed flow measurements reveal that the latter is the case. From these findings, it is clear that a stall warning system based on blade passing signature irregularity would be difficult to implement in an aero-engine where tip-clearance size and eccentricity change during each flight cycle and over the life of the compressor.

References

1.
Moore
,
F. K.
, and
Greitzer
,
E. M.
,
1986
, “
A Theory of Post-Stall Transients in Axial Compression Systems. I. Development of Equations
,”
ASME J. Eng. Gas Turbines Power
,
108
, pp.
68
76
.10.1115/1.3239887
2.
Greitzer
,
E. M.
, and
Moore
,
F. K.
,
1986
, “
A Theory of Post-Stall Transients in Axial Compression Systems. II. Application
,”
ASME J. Eng. Gas Turbines Power
,
108
, pp.
231
239
.10.1115/1.3239893
3.
Camp
,
T. R.
, and
Day
,
I. J.
,
1998
, “
A Study of Spike and Modal Stall Inception in a Low-Speed Axial Compressor
,”
ASME J. Turbomach.
,
120
, pp.
393
401
.10.1115/1.2841730
4.
Strazisar
,
A. J.
,
Bright
,
M. M.
,
Thorp
,
S.
,
Culley
,
D. E.
, and
Suder
,
K. L.
,
2004
, “
Compressor Stall Control Through Endwall Recirculation
,” Proceedings of ASME Turbo Expo 2004,
Vienna
,
Austria
,
June
14
17
,
ASME
Paper No. GT2004-54295. 10.1115/GT2004-54295
5.
März
,
J.
,
Hah
,
C.
, and
Neise
,
W.
,
2001
, “
An Experimental and Numerical Investigation into the Mechanisms of Rotating Instability
,”
Proceedings of ASME Turbo Expo 2001
,
New Orleans, LA
,
June
4
7
, Paper No. 2001-GT-0536.
6.
Dhingra
,
M.
,
Neumeier
,
Y.
,
Prasad
,
J. V. R.
, and
Shin
,
H.-W.
,
2003
, “
Stall and Surge Precursors in Axial Compressors
,”
39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit
,
Hunstville, AL
,
July
20
23
, Paper No. AIAA 2003-4425.
7.
Liu
,
Y.
,
Dhingra
,
M.
, and
Prasad
,
J. V. R.
,
2009
, “
Active Compressor Stability Management via a Stall Margin Control Mode
,” Proceedings of ASME Turbo Expo 2009,
Orlando, FL
, June 8–12,
ASME
Paper No. GT2009-60140.10.1115/GT2009-60140
8.
Christensen
,
D.
,
Cantin
,
P.
,
Gutz
,
D.
,
Szucs
,
P. N.
,
Wadia
,
A. R.
,
Armor
,
J.
,
Dhingra
,
M.
,
Neumeier
,
Y.
, and
Prasad
,
J. V. R.
,
2008
, “
Development and Demonstration of a Stability Management System for Gas Turbine Engines
,”
ASME J. Turbomach.
,
130
, pp.
1
8
. 10.1115/1.2777176
9.
Gannon
,
A. J.
,
Hobson
,
G. V.
, and
Davis
,
W. L.
,
2010
, “
Axial Transonic Rotor and Stage Behaviour Near the Stability Limit
,” Proceedings of ASME Turbo Expo 2010,
Glasgow, UK
,
June
14
18
,
ASME
Paper No. GT2010-23713. 10.1115/GT2010-23713
10.
Graf
,
M. B.
,
Wong
,
T. S.
,
Greitzer
,
E. M.
,
Marble
,
F. E.
,
Tan
,
C. S.
,
Shin
,
H.-W.
, and
Wisler
,
D. C.
,
1998
, “
Effects of Non-Axisymmetric Tip Clearance on Axial Compressor Performance and Stability
,”
ASME J. Turbomach.
,
120
, pp.
648
661
.10.1115/1.2841774
11.
Bennington
,
M. A.
,
Ross
,
M. H.
,
Cameron
,
J. D.
,
Morris
,
S. C.
,
Du
,
J.
,
Lin
,
F.
, and
Chen
,
J.
,
2010
, “
An Experimental and Computational Investigation of Tip Clearance Flow and its Impact on Stall Inception
,” Proceedings of ASME Turbo Expo 2010,
Glasgow, UK
,
June
14
18
,
ASME
Paper No. GT2010-23516. 10.1115/GT2010-23516
12.
Simpson
,
A. K.
, and
Longley
,
J. P.
,
2007
, “
An Experimental Study of the Inception of Rotating Stall in a Single-Stage Low-Speed Axial Compressor
,” Proceedings of ASME Turbo Expo 2007, May 14–17,
ASME
Paper No. GT2007-27181
.10.1115/GT2007-27181
13.
Hynes
,
T. P.
, and
Greitzer
,
E. M.
,
1987
, “
A Method for Assessing Effects of Circumferential Flow Distortion on Compressor Stability
,”
ASME J. Turbomach.
,
109
, pp.
371
379
.10.1115/1.3262116
14.
Mailach
,
R.
,
Lehmann
,
I.
, and
Vogeler
,
K.
,
2001
, “
Rotating Instabilities in an Axial Compressor Originating From the Fluctuating Blade Tip Vortex
,”
ASME J. Turbomach.
,
123
, pp.
453
463
.10.1115/1.1370160
15.
Wisler
,
D. C.
,
Beacher
,
B. F.
, and
Shin
,
H-W.
,
2002
, “
Effects of Loading and Clearance Variation on Tip Vortex and Endwall Blockage
,”
Proceedings of the 9th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery
,
Honolulu, HI
,
February
10
14
.
16.
Inoue
,
M.
,
Kuroumoru
,
M.
,
Tanino
,
T.
,
Yoshida
,
S.
, and
Furukawa
,
M.
,
2001
, “
Comparative Studies on Short and Long Length-Scale Stall Cell Propagating in an Axial Compressor Rotor
,”
ASME J. Turbomach.
,
123
, pp,
24
32
.10.1115/1.1326085
You do not currently have access to this content.