The stable operating range of a centrifugal compressor stage of an engine turbocharger is limited at low mass flow rates by aerodynamic instabilities which can lead to the onset of rotating stall or surge. There have been many techniques employed to increase the stable operating range of centrifugal compressor stages. The literature demonstrates that there are various possibilities for adding special treatments to the nominal diffuser vane geometry, or including injection or bleed flows to modify the diffuser flow field in order to influence diffuser stability. One such treatment is the porous throat diffuser (PTD). Although the benefits of this technique have been proven in the existing literature, a comprehensive understanding of how this technique operates is not yet available. This paper uses experimental measurements from a high pressure ratio (PR) compressor stage to acquire a sound understanding of the flow features within the vaned diffuser which affect the stability of the overall compression system and investigate the stabilizing mechanism of the porous throat diffuser. The nonuniform circumferential pressure imposed by the asymmetric volute is experimentally and numerically examined to understand if this provides a preferential location for stall inception in the diffuser. The following hypothesis is confirmed: linking of the diffuser throats via the side cavity equalizes the diffuser throat pressure, thus creating a more homogeneous circumferential pressure distribution, which delays stall inception to lower flow rates. The results of the porous throat diffuser configuration are compared to a standard vaned diffuser compressor stage in terms of overall compressor performance parameters, circumferential pressure nonuniformity at various locations through the compressor stage and diffuser subcomponent analysis. The diffuser inlet region was found to be the element most influenced by the porous throat diffuser, and the stability limit is mainly governed by this element.

References

References
1.
Greitzer
,
E. M.
,
1981
, “
The Stability of Pumping Systems—The 1980 Freeman Scholar Lecture
,”
ASME J. Fluids Eng.
,
103
(2), pp.
193
242
.
2.
Day
,
I. J.
,
2016
, “
Stall, Surge and 75 Years of Research
,”
ASME J. Turbomach.
,
138
(
1
), p.
011001
.
3.
Moore
,
F.
, and
Greitzer
,
E.
,
1986
, “
A Theory of Post-Stall Transients in Axial Compression Systems: Part I—Development of Equations
,”
ASME J. Eng. Gas Turbines Power
,
108
(
1
), pp.
231
239
.
4.
McDougall
,
N.
,
Cumpsty
,
N.
, and
Hynes
,
T.
,
1990
, “
Stall Inception in Axial Flow Compressors
,”
ASME J. Turbomach.
,
112
(
1
), pp.
116
123
.
5.
Day
,
I. J.
,
1993
, “
Stall Inception in Axial Flow Compressors
,”
ASME J. Turbomach.
,
115
(
1
), pp.
1
9
.
6.
Camp
,
T.
, and
Day
,
I.
,
1998
, “
A Study of Spike and Modal Stall Phenomena in a Low Speed Axial Compressor
,”
ASME J. Turbomach.
,
120
(
3
), pp.
393
401
.
7.
Pullan
,
G.
,
Young
,
A. M.
,
Day
,
I. J.
,
Greitzer
,
E. M.
, and
Spakovszky
,
Z. S.
,
2015
, “
Origins and Structure of Spike-Type Rotating Stall
,”
ASME J. Turbomach.
,
137
(
5
), p.
051007
.
8.
Everitt
,
J. N.
, and
Spakovszky
,
Z. S.
,
2012
, “
An Investigation of Stall Inception in Centrifugal Compressor Vaned Diffuser
,”
ASME J. Turbomach.
,
135
(
1
), p.
11025
.
9.
Fisher
,
F.
,
1988
, “Application of Map Width Enhancement Devices to Turbocharger Compressor Stages,”
SAE
Paper No. 880794.
10.
Hunziker
,
R.
, and
Gyarmathy
,
G.
,
1994
, “
The Operational Stability of a Centrifugal-Compressor and Its Dependence on the Characteristics of the Subcomponents
,”
ASME J. Turbomach.
,
116
(
2
), pp.
250
259
.
11.
Spakovszky
,
Z. S.
,
2004
, “
Backward Traveling Rotating Stall Waves in Centrifugal Compressors
,”
ASME J. Turbomach.
,
126
(1), pp.
1
12
.
12.
Spakovszky
,
Z. S.
, and
Roduner
,
C. H.
,
2009
, “
Spike and Modal Stall Inception in an Advanced Turbocharger Centrifugal Compressor
,”
ASME J. Turbomach.
,
131
(3), p.
031012
.
13.
Skoch
,
G. J.
,
2003
, “
Experimental Investigation of Centrifugal Compressor Stabilization Techniques
,”
ASME J. Turbomach.
,
125
(
4
), pp.
704
713
.
14.
Skoch
,
G. J.
,
2005
, “
Experimental Investigation of Diffuser Hub Injection to Improve Centrifugal Compressor Stability
,”
ASME J. Turbomach.
,
127
(
1
), pp.
107
117
.
15.
Amann
,
C. A.
,
Nordenson
,
G. E.
, and
Skellenger
,
G. D.
,
1975
, “
Casing Modification for Increasing the Surge Margin of a Centrifugal Compressor in an Automotive Turbine Engine
,”
ASME J. Eng. Power
,
97
(
3
), pp.
329
336
.
16.
Ohta
,
Y.
,
Goto
,
T.
, and
Outa
,
E.
,
2010
, “Unsteady Behaviour and Control of Diffuser Leading-Edge Vortex in a Centrifugal Compressor,”
ASME
Paper No. GT2010-22394.
17.
Tamaki
,
H.
,
Zheng
,
X.
, and
Zhang
,
Y.
,
2012
, “
Experimental Investigation of High Pressure Ratio Centrifugal Compressor With Axisymmetric and Non-Axisymmetric Recirculation Device
,”
ASME J. Turbomach.
,
135
(
3
), p.
031023
.
18.
Steglich, T.
,
Kitzinger, J.
,
Seume, J. R.
,
Van den Braembussche, R. A.
, and
Prinsier, J.
,
2008
, “
Improved Diffuser/Volute Combinations for Centrifugal Compressors
,”
ASME J. Turbomach.
,
130
(1), p. 011014.
19.
Raw
,
J. A.
,
1986
, “
Surge Margin Enhancement by a Porous Throat Diffuser
,”
Can. Aeronaut. Space J.
,
32
(
1
), pp.
54
60
.
20.
Ono
,
Y.
,
2013
, “
Solutions for Better Engine Performance at Low Load by Mitsubishi Turbochargers
,”
27th CIMAC World Congress
, Shanghai, China, May 13–16, Paper No. 15.
21.
Perrone
,
G. L.
,
Boorman
,
R. W.
,
Holbrook
,
M. R.
, and
Zanelli
,
E. A.
,
1978
, “Centrifugal Compressor With Improved Range,” The Garrett Corporation, Los Angeles, CA, U.S. Patent No.
US4131389
.http://www.google.com/patents/US4131389
22.
Exley
,
T.
,
Tate
,
D. L.
, and
Garrett
,
R. E.
,
1979
, “Rotary Compressors,” AlliedSignal, Inc., Morristown, NJ, U.S. Patent No.
US4164845
.https://www.google.com/patents/US4164845
23.
Exley
,
J. T.
,
1992
, “Mixed Flow Compressor Surge Margin Gain Using a Manifolded Diffuser System,”
AIAA
Paper No. 92-3753.
24.
Cornelius
,
C.
,
Biesinger
,
T.
,
Zori
,
L.
,
Campregher
,
R.
,
Galpin
,
P.
, and
Braune
,
A.
,
2014
, “Efficient Time Resolved Multistage CFD Analysis Applied to Axial Compressors,”
ASME
Paper No. GT2014-26846.
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