Jet engines with boundary layer ingestion (BLI) could offer significant reductions in aircraft fuel burn compared with podded turbofans. However, the engine fans must run continuously with severe inlet distortion, which is known to reduce stability. In this paper, an experimental study has been completed on a low-speed rig fan operating with a BLI-type inlet distortion. Unsteady casing static pressure measurements have been made at multiple locations during stall events. Steady-state, full-annulus area traverses have also been performed at rotor inlet and exit at a near-stall operating point. The reduction in stability caused by BLI is found to be small. It is found that with BLI the fan can operate stably despite the presence of localized regions where the rotor operating point lies beyond the stability boundary measured in clean flow. With the BLI-type distortion applied, the measured rotor incidence varies around the annulus due to nonuniform upstream velocity and swirl. The measured amplitude of unsteady casing pressure fluctuations just prior to stall is found to correlate with the circumferential variation of rotor incidence, suggesting that rotor incidence is a key variable affecting the creation and growth of flow disturbances. In regions of high incidence, disturbances resembling local flow separations are initiated. However, in regions of low or negative incidence, any disturbances decay rapidly. Full rotating stall with BLI occurs when high incidence regions are widespread enough to sustain disturbances which can propagate around the entire annulus.

References

References
1.
Felder
,
J. L.
,
Brown
,
G. V.
,
Kim
,
H. D.
, and
Chu
,
J.
,
2011
, “
Turboelectric Distributed Propulsion in a Hybrid Wing Body
,”
20th ISABE Conference
,
Gothenburg, Sweden
, ISABE-2011-1340.
2.
Hall
,
C. A.
,
Schwartz
,
E.
, and
Hileman
,
J. I.
,
2009
, “
Assessment of Technologies for the Silent Aircraft Initiative
,”
J. Propul. Power
,
25
(
6
), pp.
1153
1162
.
3.
Uranga
,
A.
,
Drela
,
M.
,
Greitzer
,
E.
,
Titchener
,
N.
,
Lieu
,
M.
,
Siu
,
N.
,
Huang
,
A.
,
Gatlin
,
G.
, and
Hannon
,
J.
,
2014
, “
Preliminary Experimental Assessment of the Boundary Layer Ingestion Benefit for the D8 Aircraft
,”
52nd AIAA Aerospace Sciences Meeting, National Harbor
,
MD
, AIAA 2014-0906.
4.
Smith
,
L. H.
,
1993
, “
Wake Ingestion Propulsion Benefit
,”
J. Propul. Power
,
9
(
1
), pp.
74
82
.
5.
Day
,
I. J.
,
1993
, “
Stall Inception in Axial Flow Compressors
,”
ASME J. Turbomach.
,
115
(
1
), pp.
1
9
.
6.
McDougall
,
N. M.
,
Cumpsty
,
N. A.
, and
Hynes
,
T. P.
,
1990
, “
Stall Inception in Axial Compressors
,”
ASME J. Turbomach.
,
112
(
1
), pp.
116
123
.
7.
Weichert
,
S.
, and
Day
,
I. J.
,
2014
, “
Detailed Measurements of Spike Formation in an Axial Compressor
,”
ASME J. Turbomach.
,
136
(
5
), p.
051006
.
8.
Young
,
A. M.
,
Day
,
I. J.
, and
Pullan
,
G.
,
2013
, “
Stall Warning by Blade Pressure Signature Analysis
,”
ASME J. Turbomach.
,
135
(
1
), p.
011033
.
9.
Inoue
,
M.
,
Kuroumarau
,
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
(
1
), pp.
24
32
.
10.
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
.
11.
Bennington
,
M. A.
,
Ross
,
M.
,
Cameron
,
J.
,
Morris
,
S.
,
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
, GT2010-23516.
12.
Katz
,
R.
,
1958
, “
Performance of Axial Compressors With Asymmetric Inlet Flows
,” PhD thesis,
California Institute of Technology
,
Pasadena, CA
.
13.
Reid
,
C.
,
1969
, “
The Response of Axial Flow Compressors to Intake Flow Distortion
,”
Proceedings of the Gas Turbine Products and Conference Show
,
Cleveland, OH
, 69-GT-29.
14.
Williams
,
D. D.
,
1986
, “
Review of Current Knowledge of Engine Response to Distorted Inflow Conditions
,”
Engine Response to Distorted Inflow Conditions
,
Munich, Germany
, AGARD CP-400, pp.
1-1
1-32
.
15.
Longley
,
J. P.
, and
Greitzer
,
E. M.
,
1992
, “
Inlet Distortion Effects in Aircraft Propulsion System Integration
,” “
Steady and Transient Performance Prediction of Gas Turbine Engines
, AGARD LS-183, pp.
6-1
6-18
.
16.
Pearson
,
H.
, and
McKenzie
,
A. B.
,
1959
, “
Wakes in Axial Compressors
,”
J. Royal Aeronautical Soc.
,
63
, pp.
415
416
.
17.
Hynes
,
T. P.
, and
Greitzer
,
E. M.
,
1987
, “
A Method for Assessing Effects of Circumferential Flow Distortion on Compressor Stability
,”
ASME J. Turbomach.
,
109
(
3
), pp.
371
379
.
18.
Longley
,
J. P.
,
1990
, “
Measured and Predicted Effects of Inlet Distortion on Axial Compressors
,”
Proceedings of ASME Turbo Expo 1990
,
Brussels, Belgium
, 90-GT-214.
19.
Shaw
,
M. J.
,
Hield
,
P.
, and
Tucker
,
P. G.
,
2013
, “
The Effect of Inlet Guide Vanes on Inlet Flow Distortion Transfer and Transonic Fan Stability
,”
ASME J. Turbomach.
,
136
(
2
), p.
021015
.
20.
Yao
,
J.
,
Gorrell
,
S. E.
, and
Wadia
,
A. R.
,
2010
, “
High-Fidelity Numerical Analysis of Per-Rev-Type Inlet Distortion Transfer in Multistage Fans
,”
ASME J. Turbomach.
,
132
(
4
), p.
041014
.
21.
Jerez Fidalgo
,
V.
,
Hall
,
C. A.
, and
Colin
,
Y.
,
2012
, “
A Study of Fan-Distortion Interaction Within the NASA Rotor 67 Transonic Stage
,”
ASME J. Turbomach.
,
134
(
5
), p.
051011
.
22.
Mistry
,
C. S.
, and
Pradeep
,
A. M.
,
2013
, “
Investigations on the Effect of Inflow Distortion on the Performance of a High Aspect Ratio, Low Speed Contra Rotating Fan Stage
,”
Proceedings of ASME Turbo Expo 2013
,
San Antonio, TX
, GT2013-94311.
23.
Florea
,
R. V.
,
Voytovych
,
D.
,
Tillman
,
G.
,
Stucky
,
M.
,
Shabbir
,
A.
,
Sharma
,
O.
, and
Arend
,
D. J.
,
2013
, “
Aerodynamic Analysis of a Boundary-Layer-Ingesting Distortion-Tolerant Fan
,”
Proceedings of ASME Turbo Expo 2013
,
San Antonio, TX
, GT2013-94656.
24.
Gunn
,
E. J.
, and
Hall
,
C. A.
,
2014
, “
Aerodynamics of Boundary Layer Ingesting Fans
,”
Proceedings of ASME Turbo Expo 2014
,
Dusseldorf, Germany
, GT2014-26142.
25.
Madani
,
V.
, and
Hynes
,
T. P.
,
2009
, “
Boundary Layer Ingesting Intakes: Design and Optimization
,”
Proceedings of XIX International Symposium on Air Breathing Engines
,
Montreal, Canada
, ISABE 2009-1346.
You do not currently have access to this content.