The operating range of a compressor is usually limited by the rapid growth of three-dimensional (3D) separations in the endwall flow region. In contrast, the freestream region is not usually close to its diffusion limit and has little effect on overall range. In light of these two distinct flow regions, this paper considers how velocity triangles in the endwall region should be designed to give a more balanced spanwise failure across the span of a blade row. In the first part of this paper, the sensitivity of 3D separations in a single blade row to variations in realistic multistage inlet conditions and endwall geometry is investigated. It is shown that a blade's 3D separation size is largely controlled by the dynamic pressure within the incoming endwall “repeating stage” boundary layer and not the detailed local geometry within the blade row. In the second part of this paper, the traditional design process is “flipped.” Instead of redesigning a blade's endwall geometry to cope with a particular inlet profile into the blade row, the endwall region is redesigned in the multistage environment to “tailor” the inlet profile into downstream blade rows, giving the designer a new extra degree-of-freedom. This extra degree-of-freedom is exploited to balance freestream and endwall operating range, resulting in a compressor having an increased operating range of ∼20%. If this increased operating range is traded with reduced blade count, it is shown that a design efficiency improvement of ∼0.5% can be unlocked.

References

References
1.
Gallimore
,
S. J.
,
Bolger
,
J. J.
,
Cumpsty
,
N. A.
,
Taylor
,
M. J.
,
Wright
,
P. I.
, and
Place
,
J. M. M.
,
2002
, “
The Use of Sweep and Dihedral in Multistage Axial Flow Compressor Blading—Part I: University Research and Methods Development
,”
ASME J. Turbomach.
,
124
(
4
), pp.
521
532
.
2.
Taylor
,
J. V.
, and
Miller
,
R. J.
,
2015
, “
Competing 3D Mechanisms in 3D Flows
,”
ASME
Paper No. GT2015-43322.
3.
Holloway
,
P. R.
,
Knight
,
G. L.
,
Koch
,
C. C.
, and
Shaffer
,
S. J.
,
1982
, “
Energy Efficient Engine High Pressure Compressor Detail Design Report
,”
Technical Report No. NASA-CR-165558
.
4.
Wisler
,
D. C.
,
1985
, “
Loss Reduction in Axial-Flow Compressors Through Low-Speed Model Testing
,”
ASME J. Eng. Gas Turbines Power
,
107
(
2
), pp.
354
363
.
5.
Kanjirakkad
,
V.
,
Goddard
,
A.
,
Hodson
,
H.
, and
Longley
,
J.
,
2010
,
SMURF Research Compressor Report: Build-1 Experimentation
,
University of Cambridge
,
Cambridge, UK
.
6.
Moinier
,
P.
, and
Giles
,
M. B.
,
1998
, “
Preconditioned Euler and Navier–Stokes Calculations on Unstructured Grids
,” 6th
ICFD
Conference on Numerical Methods for Fluid Dynamics
, Oxford, UK.
7.
Menter
,
F. R.
,
1992
, “
Improved Two-Equation k-Omega Turbulence Models for Aerodynamic Flows
,”
NASA STI/Recon Technical Report No. 93
.
8.
Shahpar
,
S.
, and
Lapworth
,
L.
,
2003
, “
PADRAM: Parametric Design and Rapid Meshing System for Turbomachinery Optimisation
,”
ASME
Paper No. GT2003-38698.
9.
McKenzie
,
A. B.
,
1997
,
Axial Flow Fans and Compressors
,
Ashgate Publishing, Farnham
,
Surrey, UK
.
10.
To
,
H.-O.
, and
Miller
,
R. J.
,
2015
, “
The Effect of Aspect Ratio on Compressor Performance
,”
ASME
Paper No. GT2015-43016.
11.
Smith
,
L. H.
,
1970
, “
Casing Boundary Layers in Multistage Axial Flow Compressors
,”
Flow Research on Blading
, Vol.
106
, Elsevier, Amsterdam, The Netherlands, pp.
275
304
.
12.
Goodhand
,
M. N.
, and
Miller
,
R. J.
,
2012
, “
The Impact of Real Geometries on Three-Dimensional Separations in Compressors
,”
ASME J. Turbomach.
,
134
(
2
), p.
021007
.
13.
Wadia
,
A. R.
, and
Beacher
,
B. F.
,
1990
, “
Three-Dimensional Relief in Turbomachinery Blading
,”
ASME J. Turbomach.
,
112
(
4
), pp.
587
596
.
14.
Cumpsty
,
N. A.
,
1990
, “
Discussion: Three-Dimensional Relief in Turbomachinery Blading
,”
ASME J. Turbomach.
,
112
(
4
), pp.
596
598
.
15.
Koch
,
C. C.
,
1981
, “
Stalling Pressure Rise Capability of Axial Flow Compressor Stages
,”
ASME J. Eng. Power
,
103
(
4
), pp.
645
656
.
16.
Smith
,
L. H.
, Jr.
,
1958
, “
Recovery Ratio: A Measure of the Loss Recovery Potential of Compressor Stages
,”
ASME
,
80
(3), pp.
517
524
.
17.
Ashby
,
G. C.
, Jr.
,
1957
, “
Investigation of the Effect of Velocity Diagram on Inlet Total-Pressure Distortions Through Single-Stage Subsonic Axial-Flow Compressors
,”
NACA Research Memorandum No. NACA RM L57A03
.
18.
Smith
,
J. L. H.
,
2002
, “
Axial Compressor Aerodesign Evolution at General Electric
,”
ASME J. Turbomach.
,
124
(
3
), pp.
321
330
.
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