Ported shroud is a cost-effective casing treatment that can greatly improve stability of centrifugal compressors. It is widely used in turbochargers and other applications where compressors with a wide flow range are required. This paper reviews the development of the ported shroud concept from its first conception in the 1980 s to its current various configurations and explores the underline mechanisms that deliver the performance improvement. It is explained that, by removing stagnant fluid from impeller inducer shroud end wall boundary-layer region and recirculating it to the impeller inlet, blade loading near the inducer shroud is increased with improved inlet suction. For transonic flow, the ported shroud weakens the shock wave and reduces flow separation on the inducer suction surface. It is argued that the effectiveness of ported shroud is a balance of blade loading and the flow loss inside the ported shroud cavity. The loss needs to be minimized if ported shroud is to be more effective. Blade loading may be increased by various methods, such as using high inducer blade turning and using full-bladed impellers. The blade loading can also be improved by removing flow swirl in ported shroud flow by vanes or imposing negative swirl by vanes in ported shroud. Circumferential flow variation caused by volute housing can be taken into account by variable pitch vanes or by variable port position.

References

References
1.
Jansen
,
W.
,
Carter
,
A.
, and
Swarden
,
M.
,
1980
, “
Improvement in Surge Margin for Centrifugal Compressors
,”
AGARD 55th Specialists' Meeting: Centrifugal Compressor, Flow Phenomena and Performance, Brussels
,
Belgium, May, AGARD-CP-282, NO. 19
.
2.
Fisher
,
F. B.
, and
Langdon
,
P. J.
,
1988
, “
Compressors
,” U.S. Patent No. 4,743,161.
3.
Fisher
,
F. B.
,
1988
, “
Application of Map Width Enhancement Devices to Turbocharger Compressor Stages
,”
SAE
Paper No. 880794. 10.4271/880794
4.
Cabrales
,
J.
,
LaRue
,
G.
,
Gu
,
R.
,
Lemon
,
A.
, and
Wilson
,
J.
,
2004
, “Apparatus, System and Method for Minimizing Resonant Forces in A Compressor,” U.S. Patent No. 2004/0223843 A1.
5.
Nikpour
,
B.
,
2004
, “
Turbocharger Compressor Flow Range Improvement for Future Heavy Duty Diesel Engines
,”
THIESEL 2004 Conference on Thermo and Fluid Dynamic Processes in Diesel Engines
,
Valencia, Spain
, September 7–10.
6.
Chen
,
H.
,
2009
, “
Inclined Rib Ported Shroud Compressor Housing
,” U.S. Patent No. 2009/7475539 B2.
7.
Yamaguchi
,
S.
,
Yamaguchi
,
H.
,
Goto
,
S.
,
Nakao
,
H.
and
Nakamura
,
F.
,
2002
, “
The Development of Effective Casing Treatment for Turbocharger Compressors
,”
IMechE Seventh International Conference on Turbochargers and Turbocharging
, London, May 17–18, pp.
23
32
.
8.
Chen
,
H.
, and
Yin
,
J.
,
2006
, “
Turbocharger Compressor Development for Diesel Passenger Car Applications
,”
IMechE Eighth International Conference on Turbochargers and Turbocharging
, London, May 17–18.
9.
Yin
,
J.
,
Chen
,
H.
,
Deschatrettes
,
N.
,
Yin
,
J.
,
Vrbas
,
G.
, and
Thoren
,
D.
,
2009
, “
Centrifugal Compressor With Surge Control and Associated Method
,” U.S. Patent No. 2007/0217902.
10.
Tamaki
,
H.
,
2011
, “
Effect of Recirculation Device With Counter Swirl Vane on Performance of High Pressure Ratio Centrifugal Compressor
,”
ASME Turbo Expo 2011
, Vancouver, Canada, June 6–10,
ASME
Paper No. GT2011-45360. 10.1115/GT2011-45360
11.
Tanna
,
R. P.
,
Yin
,
J.
,
Sirakov
,
B.
, and
Barbarie
,
V.
,
2010
, “
Development of Ported Shroud Compressor Housing With Reduced Compressor Blade Pass Source Acoustic Level
,”
IMechE Ninth International Conference on Turbochargers and Turbocharging
, London, May 19–20, Paper No. C001/008/2010, pp.
115
124
.
12.
Yang
,
M. Y.
,
Zheng
,
X.
,
Zhang
,
Y.
,
Bamba
,
T.
,
Tamaki
,
H.
,
Huenteler
,
J.
, and
Li
,
Z.
,
2010
, “
Stability Improvement of High Pressure Ratio Turbocharger Centrifugal Compressor by Asymmetric Flow Control—Part I: Non-Axisymmetric Flow in Centrifugal Compressor
,”
ASME Turbo Expo 2010
, Glasgow, UK, June 14–18,
ASME
Paper No. GT2010-22581. 10.1115/GT2010-22581
13.
Zheng
,
X. Q.
,
Zhang
,
Y.
,
Yang
,
M.
,
Bamba
,
T.
, and
Tamaki
,
H.
,
2010
, “
Stability Improvement of High Pressure Ratio Turbocharger Centrifugal Compressor by Asymmetric Flow Control—Part II: Non-Axisymmetric Self Recirculation Casing Treatment
,”
ASME Turbo Expo 2010
, Glasgow, UK, June 14–18,
ASME
Paper No. GT2010-22582. 10.1115/GT2010-22582
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