The matching of a vaned diffuser with a centrifugal impeller is examined with a one-dimensional (1D) analysis combined with extensive experimental data. A matching equation is derived to define the required throat area of the diffuser relative to the throat area of the impeller at different design speeds and validated by comparison with a wide range of compressor designs. The matching equation is then used to give design guidelines for the throat area of vaned diffusers operating with impellers at different tip-speed Mach numbers. An analysis of test data for a range of high pressure ratio turbocharger compressor stages is presented in which different matching between the diffuser and the impeller has been experimentally examined. The test data includes different impellers with different diffuser throat areas over a wide range of speeds. It is shown that the changes in performance with speed and diffuser throat area can be explained on the basis of the tip-speed Mach number which causes both the diffuser and impeller to choke at the same mass flow. Based on this understanding, a radial compressor map prediction method is extended to include this parameter, so that more accurate maps for matched and mismatched vaned diffusers can be predicted.

References

References
1.
Cukurel
,
B.
,
Lawless
,
P. B.
, and
Fleeter
,
S.
,
2010
, “
Particle Image Velocity Investigation of a High Speed Centrifugal Compressor Diffuser: Spanwise and Loading Variations
,”
ASME J. Turbomach.
,
132
(
2
), p. 021010.10.1115/1.3104616
2.
Deniz
,
S.
,
Cumpsty
,
N. A.
, and
Greitzer
,
E. M.
,
1998
, “
Effects of Inlet Flow Field Conditions on the Performance of Centrifugal Compressor Diffusers: Part 2—Straight-Channel Diffuser
,”
ASME J. Turbomach.
,
122
(
1
), pp. 11–12.10.1115/1.555424
3.
Shum
,
Y. K. P.
,
Tan
,
C. S.
, and
Cumpsty
,
N. A.
,
2000
, “
Impeller-Diffuser Interaction in a Centrifugal Compressor
,”
ASME J. Turbomach.
,
122
(
4
), pp.
777
786
.10.1115/1.1308570
4.
Robinson
,
C. J.
,
Casey
,
M. V.
,
Hutchinson
,
B.
, and
Steed
,
R.
,
2012
, “
Impeller-Diffuser Interaction in Centrifugal Impellers
,”
ASME
Paper No. GT2012-69151. 10.1115/GT2012-69151
5.
Klassen
,
H. A.
,
Wood
,
J. R.
, and
Schumann
,
L.
,
1977
, “
Experimental Performance of a 16.10-Centimeter-Tip-Diameter Sweptback Centrifugal Compressor Designed for a 6:1 Pressure Ratio
,” NASA Lewis Research Center and U.S. Army Air Mobility R&D Laboratory, Cleveland, OH, Technical Memorandum No. NASA TM X-3552.
6.
Rodgers
,
C
.,
2005
, “
Flow Ranges of 8.0:1 Pressure Ratio Centrifugal Compressors for Aviation Applications
,”
ASME
Paper No. GT2005-68041.10.1115/GT2005-68041
7.
Yoshinaka
,
T.
,
1977
, “
Surge Responsibility and Range Characteristics of Centrifugal Compressors
,”
Joint Gas Turbine Conference
,
Tokyo, Japan
, May 22–27, pp.
381
390
.
8.
Cumpsty
,
N. A.
,
1989
,
Compressor Aerodynamics
,
Longman Group Ltd.
,
Harlow, Essex, UK
.
9.
Tamaki
,
H.
,
Nakao
,
H.
, and
Saito
,
M.
,
1999
, “
The Experimental Study of Matching Between Centrifugal Compressor Impeller and Diffuser
,”
ASME J. Turbomach.
,
121
(
1
), pp.
113
118
.10.1115/1.2841218
10.
Rusch
,
D.
, and
Casey
,
M. V.
,
2013
, “
The Design Space Boundaries for High Flow Capacity Centrifugal Compressors
,”
ASME J. Turbomach.
,
135
(
3
), p.
031035
.10.1115/1.4007548
11.
Casey
,
M. V.
, and
Robinson
,
C. J.
,
2013
, “
A Method to Estimate the Performance Map of a Centrifugal Compressor Stage
,”
ASME J. Turbomach.
,
135
(
2
), p.
021034
.10.1115/1.4006590
12.
Dixon
,
S. L.
, and
Hall
,
C. A.
,
2010
,
Fluid Mechanics and Thermodynamics of Turbomachinery
,
6th ed.
,
Butterworth-Heinemann
,
Boston, MA
.
13.
Casey
,
M.
V
, and
Schlegel
,
M.
,
2010
, “
Estimation of the Performance of Turbocharger Compressors at Extremely Low Pressure Ratios
,”
Proc. Inst. Mech. Eng., Part A
,
224
(
2
), pp.
239
250
.10.1243/09576509JPE810
14.
Lohmberg
,
A.
,
Casey
,
M. V.
, and
Ammann
,
S.
,
2003
, “
Transonic Radial Compressor Inlet Design
,”
Proc. Inst. Mech. Eng., Part A
,
217
(
4
), pp.
367
374
.10.1243/095765003322315423
15.
Rodgers
,
C.
,
1982
, “
The Performance of Centrifugal Compressor Channel Diffusers
,”
27th ASME International Gas Turbine Conference and Exhibit
,
London, April 18–22
,
ASME
Paper No. 82-GT-10.
16.
Policke
,
O.
,
1995
, “
Versuche als Wichtiges Element der Turbolader Entwicklung
,”
ABB Tech.
,
1
, pp.
36
42
.
17.
Swain
,
E.
,
2005
, “
Improving a One-Dimensional Centrifugal Compressor Performance Prediction Method
,”
Proc. Inst. Mech. Eng., Part A
,
219
(8), pp.
653
659
.10.1243/095765005X31351
18.
Dalbert
,
P.
,
Casey
,
M. V.
, and
Schurter
,
E.
,
1988
, “
Development, Testing and Performance Prediction of Radial Stages for Multi-Stage Industrial Compressors
,”
ASME J. Turbomach.
,
110
(3), pp.
283
292
.10.1115/1.3262194
19.
Daily
,
J. W.
, and
Nece
,
R. E.
,
1960
, “
Chamber Dimension Effects on Induced Flow and Frictional Resistance of Enclosed Rotating Disks
,”
ASME J. Basic Eng.
,
82
(1), pp.
217
232
.10.1115/1.3662532
You do not currently have access to this content.