Boundary layer ingestion (BLI) is a propulsion technology being investigated at NASA by the Advanced Aircraft Transportation Technology (AATT) Program to facilitate a substantial reduction in aircraft fuel burn. In an attempt to experimentally demonstrate an increase in the propulsive efficiency of a BLI engine, a first-of-its-kind subscale high-bypass ratio 22″ titanium fan, designed to structurally withstand significant unsteady pressure loading caused by a heavily distorted axial air inflow, was built and then tested in the transonic section of the GRC 8′ × 6′ supersonic wind tunnel. The vibratory responses of a subset of fan blades were measured using strain gages placed in four different blade pressure side surface locations. Response highlights include a significant response of the blade's first resonance to engine order excitation below idle as the fan was spooled up and down. The fan fluttered at the design speed under off operating line, low flow conditions. This paper presents the blade vibration response characteristics over the operating range of the fan and compares them to predicted behaviors. It also provides an assessment of this distortion-tolerant fan's (DTF) ability to withstand the harsh dynamic BLI environment over an entire design life of billions of load cycles at design speed.

References

References
1.
Smith
,
L. H.
,
1993
, “
Wake Ingestion Propulsion Benefit
,”
AIAA J. Propul. Power
,
9
(
1
), pp.
74
82
.
2.
Daggett
,
D.
,
Kawai
,
R.
, and
Friedman
,
D.
,
2003
, “
Blended Wing Body Systems Studies: Boundary Layer Ingestion Inlets With Active Flow Control
,” NASA Langley Research Center, Hampton, VA, Report No.
NASA/CR-2003-212670
.https://ntrs.nasa.gov/search.jsp?R=20040031343
3.
Kawai
,
R.
,
Friedman
,
D.
, and
Serrano
,
L.
,
2006
, “
Blended Wing Body (BWB) Boundary Layer Ingestion (BLI) Inlet Configuration and Systems Studies
,” NASA Langley Research Center, Hampton, VA, Report No.
NASA/CR-2006-214534
.https://ntrs.nasa.gov/search.jsp?R=20070006754
4.
Plas
,
A. P.
,
2007
, “
Performance of a Boundary Layer Ingesting (BLI) Propulsion System
,”
AIAA
Paper No. 2007-450.
5.
Nickol
,
C. L.
,
2008
, “
Silent Aircraft Initiative Concept Risk Assessment
,” NASA Langley Research Center, Hampton, VA, Report No.
NASA/TM-2008-215112
.https://ntrs.nasa.gov/search.jsp?R=20080012497
6.
Nickol
,
C. L.
, and
McCullers
,
L. A.
,
2009
, “
Hybrid Wing Body Configuration System Studies
,”
AIAA
Paper No. 2009-931.
7.
Arend
,
D. J.
,
Wolter
,
J. D.
,
Hirt
,
S. M.
,
Provenza
,
A. J.
,
Gazzaniga
,
J. A.
,
Cousins, W. T.
,
Hardin, L. W.
, and
Sharma, O. P.
,
2017
, “
Experimental Evaluation of an Embedded Boundary Layer Ingesting Propulsor for Highly Efficient Subsonic Cruise Aircraft
,”
AIAA
Paper No. 2017-5041.
8.
Cousins
,
W. T.
,
Voytovych
,
D.
,
Tillman
,
G.
, and
Gray
,
E.
,
2017
, “
Design of a Distortion-Tolerant Fan for a Boundary-Layer Ingesting Embedded Engine Application
,”
AIAA
Paper No. 2017-5042.
9.
Hardin
,
L. W.
,
Cousins
,
W. T.
,
Wolter
,
J. D.
,
Arend
,
D. J.
, and
Hirt
,
S. M.
,
2018
, “
Data Analysis Techniques for Fan Performance in Highly-Distorted Flows From Boundary Layer Ingesting Inlets
,”
AIAA
Paper No. 2018-1888.
10.
Duffy
,
K. P.
,
Provenza
,
A. J.
,
Bakhle
,
M. A.
,
Min
,
J. B.
, and
Abdul-Aziz
,
A.
,
2018
, “
Laser Displacement Measurements of Fan Blades in Resonance and Flutter During the Boundary Layer Ingesting Inlet and Distortion-Tolerant Fan Test
,”
AIAA
Paper No. 2018-1892.
11.
Bakhle
,
M. A.
,
Reddy
,
T. S.
,
Coroneos
,
R. M.
,
Min
,
J. B.
,
Provenza
,
A. J.
,
Duffy
,
K. P.
,
Stefko
,
G. L.
, and
Heinlein
,
G.
,
2018
, “
Aeromechanics Analysis of a Distortion-Tolerant Fan With Boundary Layer Ingestion
,”
AIAA
Paper No. 2018-1891.
12.
Min
,
J. B.
,
Reddy
,
T. S.
,
Bakhle
,
M. A.
,
Coroneos
,
R. M.
,
Stefko
,
G. L.
,
Provenza
,
A. J.
, and
Duffy
,
K. P.
,
2018
, “
Cyclic Symmetry Finite Element Forced Response Analysis of a Distortion Tolerant Fan With Boundary Layer Ingestion
,”
AIAA
Paper No. 2018-1890.
13.
Cardinale
,
V. M.
,
Bankhead
,
H. R.
, and
McKay
,
R. A.
,
1980
, “
Experimental Verification of Turboblading Aeromechanics
,”
Turbine Engine Testing AGARD Conference
, Session IV Complete Powerplant Testing, Part I, p. 23.
14.
Bakhle
,
M. A.
,
Reddy
,
T. S.
,
Herrick
,
G. P.
,
Shabbir
,
A.
, and
Florea
,
R. V.
,
2012
, “
Aeromechanics Analysis of a Boundary Layer Ingesting Fan
,”
AIAA
Paper No. 2012-3995.
15.
Bakhle
,
M. A.
,
Reddy
,
T. S.
, and
Coroneos
,
R. M.
,
2014
, “
Forced Response Analysis of a Fan With Boundary Layer Inlet Distortion
,”
AIAA
Paper No. 2014-3734.
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