The viability of boundary layer ingesting (BLI) engines for future aircraft propulsion is dependent on the ability to design robust, efficient engine fan systems for operation with continuously distorted inlet flow. A key step in this process is to develop an understanding of the specific mechanisms by which an inlet distortion affects the performance of a fan stage. In this paper, detailed full-annulus experimental measurements of the flow field within a low-speed fan stage operating with a continuous 60 deg inlet stagnation pressure distortion are presented. These results are used to describe the three-dimensional fluid mechanics governing the interaction between the fan and the distortion and to make a quantitative assessment of the impact on loss generation within the fan. A 5.3 percentage point reduction in stage total-to-total efficiency is observed as a result of the inlet distortion. The reduction in performance is shown to be dominated by increased loss generation in the rotor due to off-design incidence values at its leading edge, an effect that occurs throughout the annulus despite the localized nature of the inlet distortion. Increased loss in the stator row is also observed due to flow separations that are shown to be caused by whirl angle distortion at rotor exit. By addressing these losses, it should be possible to achieve improved efficiency in BLI fan systems.

References

References
1.
Smith
,
L. H.
,
1993
, “
Wake Ingestion Propulsion Benefit
,”
J. Propul. Power
,
9
(
1
), pp.
74
82
.10.2514/3.11487
2.
Kawai
,
R. T.
,
Friedman
,
D. M.
, and
Serrano
,
L.
,
2006
, “
Blended Wing Body (BWB) Boundary Layer Ingestion (BLI) Inlet Configuration and System Studies
,” NASA Contract Report CR-2006-214534.
3.
Hall
,
C. A.
, and
Crichton
,
D.
,
2007
, “
Engine Design Studies for a Silent Aircraft
,”
ASME J. Turbomach.
,
129
(
3
), pp.
479
487
.10.1115/1.2472398
4.
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
.10.2514/1.43079
5.
MIT, Aurora Flight Sciences, and Pratt & Whitney
,
2010
, “
N+3 Aircraft Concept Designs and Trade Studies, Final Report
,” NASA Contract Report CR-2010-216794.
6.
Felder
,
J. L.
,
Kim
,
H. D.
, and
Brown
,
G. V.
,
2009
, “
Turboelectric Distributed Propulsion Engine Cycle Analysis for Hybrid Wing Body Aircraft
,”
47th AIAA Aerospace Sciences Meeting
, Orlando, FL, January 5–8, Paper No. AIAA 2009-1132.
7.
Felder
,
J. L.
,
Brown
,
G. V.
,
Kim
,
H. D.
, and
Chu
,
J.
,
2011
, “
Turboelectric Distributed Propulsion in a Hybrid Wing Body Aircraft
,”
20th ISABE Conference
, Gothenburg, Sweden, September 12–16, Paper No. ISABE-2011-1340.
8.
Plas
,
A. P.
,
Sargeant
,
M. A.
,
Madani
,
V.
,
Crichton
,
D.
,
Greitzer
,
E. M.
,
Hynes
,
T. P.
, and
Hall
,
C. A.
,
2007
, “
Performance of a Boundary Layer Ingesting (BLI) Propulsion System
,”
45th AIAA Aerospace Sciences Meeting and Exhibit
,
Reno
,
NV, January 8–11, Paper No.
AIAA 2007-450.
9.
Gorton
,
S. A.
,
Owens
,
L. R.
,
Jenkins
,
L. N.
,
Allan
,
B. G.
, and
Schuster
,
E. P.
,
2004
, “
Active Flow Control on a Boundary-Layer-Ingesting Inlet
,”
42nd AIAA Aerospace Sciences Meeting and Exhibit
, Reno, NV, January 5–8, AIAA-2004-1203.
10.
Owens
,
L. R.
,
Allan
,
B. G.
, and
Gorton
,
S. A.
,
2006
, “
Boundary-Layer-Ingesting Inlet Flow Control
,”
44th AIAA Aerospace Sciences Meeting and Exhibit
, Reno, NV, January 9–12, AIAA 2006-839.
11.
Allan
,
B. G.
,
Owens
,
L. R.
, and
Lin
,
J. C.
,
2006
, “
Optimal Design of Passive Flow Control for a Boundary-Layer-Ingesting Offset Inlet Using Design-of-Experiments
,”
44th AIAA Aerospace Sciences Meeting and Exhibit
, Reno, NV, January 9–12, AIAA 2006-1049.
12.
Liou
,
M.-S.
, and
Lee
,
B. J.
,
2012
, “
Minimizing Inlet Distortion for Hybrid Wing Body Aircraft
,”
ASME J. Turbomach.
,
134(3)
,
p. 031020
.10.1115/1.4003072
13.
Williams
,
D. D.
,
1987
, “
Review of Current Knowledge of Engine Response to Distorted Inflow Conditions
,” AGARD CP-400,
Engine Response to Distorted Inflow Conditions
, Munich, September 8–9, pp. 1-1–1-32.
14.
Longley
,
J. P.
, and
Greitzer
,
E. M.
,
1992
, “
Inlet Distortion Effects in Aircraft Propulsion System Integration
,” AGARD LS-183, Steady and Transient Performance Prediction of Gas Turbine Engines, pp. 6-1–6-18.
15.
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
.10.1115/1.3262116
16.
SAE
,
1999
, “
Inlet Total-Pressure-Distortion Considerations for Gas-Turbine Engines
,” Standard No. AIR1419 Revision A.
17.
Greitzer
,
E. M.
, and
Griswold
,
H. R.
,
1976
, “
Compressor-Diffuser Interaction With Circumferential Flow Distortion
,”
J. Mech. Eng. Sci.
,
18
(
1
), pp.
25
38
.10.1243/JMES_JOUR_1976_018_007_02
18.
Greitzer
,
E. M.
,
Mazzawy
,
R. S.
, and
Fulkerson
,
D. A.
,
1978
, “
Flow Field Coupling Between Compression System Components in Asymmetric Flow
,”
ASME J. Eng. Power
,
100
(
1
), pp.
66
72
.10.1115/1.3446328
19.
Yao
,
J.
,
Gorrell
,
S. E.
, and
Wadia
,
A. R.
,
2010
, “
High-Fidelity Numerical Analysis of Per-Rev-Type Inlet Distortion Transfer in Multistage Fans—Part I: Simulations With Selected Blade Rows
,”
ASME J. Turbomach.
,
132
(
4
), p.
041014
.10.1115/1.3148478
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–Part II: Entire Component Simulation and Investigation
,”
ASME J. Turbomach.
,
132
(
4
), p.
041015
.10.1115/1.3148479
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
.10.1115/1.4003850
22.
Stocks
,
C. P.
, and
Bissinger
,
N. C.
,
1981
, “
The Design and Development of the Tornado Air Engine Intake
,” AGARD CP-301, Aerodynamics of Power Plant Installation, Toulouse, France, May 11–14, pp. 10-1–10-21.
23.
Flitcroft
,
J. E.
,
Dunham
,
J.
, and
Abbott
,
W. A.
,
1986
, “
Transmission of Inlet Distortion Through a Fan
,” AGARD CP-400, Engine Response to Distorted Inflow Conditions, Munich, September 8–9, pp. 13-1–13-11.
24.
Williams
,
J. G.
,
Steenken
,
W. G.
, and
Yuhas
,
A. J.
,
1996
, “
Estimating Engine Airflow in Gas-Turbine Powered Aircraft With Clean and Distorted Inlet Flows
,” NASA Contract Report No. CR-1996-198052.
25.
Walsh
,
K. R.
,
Yuhas
,
A. J.
,
Williams
,
J. G.
, and
Steenken
,
W. G.
,
1997
, “
Inlet Distortion for an F/A-18A Aircraft During Steady Aerodynamic Conditions up to 60 deg Angle of Attack
,” NASA Technical Memorandum No. TM-104329.
26.
Govardhan
,
M.
, and
Viswanath
,
K.
,
1997
, “
Investigations on an Axial Flow Fan Stage Subjected to Circumferential Inlet Flow Distortion and Swirl
,”
J. Therm. Sci.
,
6
(
4
), pp.
241
250
.10.1007/s11630-997-0003-8
27.
Wadia
,
A. R.
,
2011
, “
Experimental Investigation of a Forward Swept Rotor in a Multistage Fan With Inlet Distortion
,”
Int. J. Aerospace Eng.
,
2011
(
1
), p.
941872
.10.1155/2011/941872
28.
Strazisar
,
A. J.
,
Wood
,
J. R.
,
Hathaway
,
M. D.
, and
Suder
,
K. L.
,
1989
, “
Laser Anemometer Measurements in a Transonic Axial-Flow Fan Rotor
,” NASA Technical Paper No. 2879.
29.
Treaster
,
A. L.
, and
Yocum
,
A. M.
,
1979
, “
The Calibration and Application of Five-Hole Probes
,”
ISA Trans.
,
18
(
3
), pp.
23
34
.
30.
Reid
,
C.
,
1969
, “
The Response of Axial Flow Compressors to Intake Flow Distortion
,”
Proceedings of the Gas Turbine Products and Conference Show
, Cleveland, OH, ASME Paper No. 69-GT-29.
31.
Sun
,
P.
,
Zhong
,
J.
, and
Feng
,
G.
,
2007
, “
Flow Field Analysis of Inlet Distortion in a Transonic Fan With Straight and Bowed Stator Blade
,”Proceedings of ASME
Turbo Expo 2007
, Montreal, Canada, May 14–17,
ASME
Paper No. GT2007-27607. 10.1115/GT2007-27607
32.
Cumpsty
,
N. A.
, and
Horlock
,
J. H.
,
2006
, “
Averaging Nonuniform Flow for a Purpose
,”
ASME J. Turbomach.
,
128
(
1
), pp.
120
129
.10.1115/1.2098807
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