Abstract

This paper aims to establish an efficient and accurate computational fluid dynamic (CFD) method for calculating the flutter stability of fan blades in the presence of inlet distortion due to crosswind. Due to the asymmetry of the flow and interaction of fan and distortion, this type of analysis will require a whole assembly computational model. Therefore, reducing the computational cost needed to obtain accurate aerodynamic damping values is paramount. Mode-tracking free-flutter analyses are computationally expensive and troublesome due to the presence of many frequencies in the response signals and, hence, require long physical times to converge the aerodynamic damping. Moreover, the unsteady flow field associated with the distortion can be more significant than the one due to flutter, giving rise to additional numerical difficulties. On the other hand, the energy method approach is commonly performed for a single nodal diameter (ND) at a time, requiring many computations to establish the least stable ND. This paper proposes an alternative approach based on the multi-ND energy method. The underlying hypothesis is that the unsteady pressure scales linearly with the blade displacements, and the scattering of circumferential modes due to the distortion is negligible. The general method presented here is general and can be used to compute the aerodynamic damping for other types of distortion (such as downstream distortions due to pylon and structure).

References

1.
Vahdati
,
M.
,
Sayma
,
A. I.
,
Marshall
,
J. G.
, and
Imregun
,
M.
,
2001
, “
Mechanisms and Prediction Methods for Fan Blade Stall Flutter
,”
J. Propuls. Power
,
17
(
5
), pp.
1100
1108
.
2.
Vahdati
,
M.
,
Simpson
,
G.
, and
Imregun
,
M.
,
2011
, “
Mechanisms for Wide-Chord Fan Blade Flutter
,”
ASME J. Turbomach.
,
133
(
4
), p.
041029
.
3.
Vahdati
,
M.
, and
Cumpsty
,
N.
,
2016
, “
Aeroelastic Instability in Transonic Fans
,”
ASME J. Eng. Gas Turbines Power
,
138
(
2
), p.
022604
.
4.
Lee
,
K.-B.
,
Wilson
,
M.
, and
Vahdati
,
M.
,
2017
, “
Numerical Study on Aeroelastic Instability for a Low-Speed Fan
,”
ASME J. Turbomach.
,
139
(
7
), p.
071004
.
5.
Aotsuka
,
M.
, and
Murooka
,
T.
,
2014
, “
Numerical Analysis of Fan Transonic Stall Flutter
,”
ASME Turbo Expo 2014: Turbine Technical Conference and Exposition
,
Düsseldorf, Germany
,
June 16–20
,
American Society of Mechanical Engineers
, p.
V07BT35A020
.
6.
Vahdati
,
M.
,
Smith
,
N.
, and
Zhao
,
F.
,
2015
, “
Influence of Intake on Fan Blade Flutter
,”
ASME J. Turbomach.
,
137
(
8
), p.
081002
.
7.
Bontemps
,
T.
,
Aubert
,
S.
, and
de Pret
,
M.
,
2021
, “
Prediction of the Acoustic Reflection in a Realistic Aeroengine Intake With Three Numerical Methods to Analyze Fan Flutter
,”
ASME J. Turbomach.
,
143
(
10
), p.
101016
.
8.
Schnell
,
R.
, and
Frey
,
C.
,
2022
, “
Acoustic Feedback and Its Impact on Fan Flutter in Short Aeroengine Intakes
,”
J. Propuls. Power
,
38
(
4
), pp.
631
646
.
9.
Harjes
,
L.
,
Bode
,
C.
,
Grubert
,
J.
,
Frantzheld
,
P.
,
Koch
,
P.
, and
Friedrichs
,
J.
,
2020
, “
Investigation of Jet Engine Intake Distortions Caused by Crosswind Conditions
,”
J. Global Power Propuls. Soc.
,
4
, pp.
48
62
.
10.
Blázquez-Navarro
,
R.
, and
Corral
,
R.
,
2023
, “
Validation of Broadband Noise Prediction Methodology Based on Linearized Navier–Stokes Analyses
,”
ASME J. Turbomach.
,
145
(
9
), p.
091002
.
11.
Murphy
,
J. P.
, and
MacManus
,
D. G.
,
2011
, “
Ground Vortex Aerodynamics Under Crosswind Conditions
,”
Exp. Fluids
,
50
, pp.
109
124
.
12.
Chennuru
,
V. Y. T.
,
Zhao
,
F.
, and
Vahdati
,
M.
,
2024
, “
An Optimal Numerical Strategy for Intake in Crosswind Conditions
,”
ASME. J. Eng. Gas Turbines Power
,
146
(
7
), p.
071005
. .
13.
Batina
,
J. T.
,
1990
, “
Unsteady Euler Airfoil Solutions Using Unstructured Dynamic Meshes
,”
AIAA J.
,
28
(
8
), pp.
1381
1388
.
14.
He
,
X.
,
Zhao
,
F.
, and
Vahdati
,
M.
,
2020
, “
Evaluation of Spalart-Allmaras Turbulence Model Forms for a Transonic Axial Compressor
,” Proc. Global Power Propuls. Soc.,
Chania
,
Greece
, No. GPPS-CH-2020-0013.
15.
He
,
X.
,
Zhao
,
F.
,
Bakhle
,
M. A.
, and
Vahdati
,
M.
,
2022
, “
Detached Eddy Simulation: Recent Development and Application to Compressor Tip Leakage Flow
,”
ASME J. Turbomach.
,
144
(
1
), p.
011009
.
16.
Dhondt
,
G.
,
2024
, “CalculiX: A Free Software Three-Dimensional Structural Finite Element Program (Version 2.21) [Computer Software],” Www.dhondt.de
17.
Fidalgo
,
V. J.
,
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
.
18.
Zhang
,
W.
,
Stapelfeldt
,
S.
, and
Vahdati
,
M.
,
2020
, “
Influence of the Inlet Distortion on Fan Stall Margin at Different Rotational Speeds
,”
Aerosp. Sci. Technol.
,
98
, p.
105668
.
19.
Carnevale
,
M.
,
Wang
,
F.
, and
Di Mare
,
L.
,
2017
, “
Low Frequency Distortion in Civil Aero-engine Intake
,”
ASME J. Eng. Gas Turbines Power
,
139
(
4
), p.
041203
.
20.
Boscagli
,
L.
,
Christie
,
R.
,
MacManus
,
D.
, and
Piovesan
,
T.
,
2022
, “
Aerodynamics of a Short Intake in Crosswind
,”
Aerosp. Sci. Technol.
,
129
, p.
107826
.
21.
Burgos
,
M. A.
, and
Corral
,
A.
,
2001
, “
Application of Phase-Lagged Boundary Conditions to Rotor/Stator Interaction
,” ASME Turbo Expo 2001: Power for Land, Sea, and Air, p.
V001T03A088
, ASME Paper No. 2001-GT-586.
22.
Stapelfeldt
,
S.
,
Parry
,
T.
, and
Vahdati
,
M.
,
2015
, “
Validation of Time-Domain Single-Passage Methods for the Unsteady Simulation of a Contra-rotating Open Rotor
,”
Proc. Inst. Mech. Eng. Part A: J. Power Energy
,
229
(
5
), pp.
443
453
.
23.
Salles
,
L.
, and
Vahdati
,
M.
,
2016
, “
Comparison of Two Numerical Algorithms for Computing the Effects of Mistuning of Fan Flutter
,”
ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition: Vol. 7B: Structures and Dynamics
,
Seoul, South Korea
,
June 13–17
,
Springer
, p.
V07BT34A018
.
24.
Murphy
,
J.
,
2008
, “
Intake Ground Vortex Aerodynamics
,” Ph.D., thesis,
Cranfield University
,
Cranfield, UK
.
25.
Herrick
,
G.
,
2010
, “
Effects of Inlet Distortion on Aeromechanical Stability of a Forward-Swept High-Speed Fan
,”
46th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit
,
Nashville, TN
,
July 25–28
.
26.
Herrick
,
G. P.
,
2014
, “
Assessing Fan Flutter Stability in Presence of Inlet Distortion Using One-Way and Two-Way Coupled Methods
,”
50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference
,
Cleveland, OH
,
July 28–30
. .
27.
Iseni
,
S.
,
Micallef
,
D.
, and
Mailach
,
R.
,
2016
, “
Investigation of Inlet Distortion on the Flutter Stability of a Highly Loaded Transonic Fan Rotor
,”
ASME Turbo Expo 2016: Turbomachinery Technical Conference and Exposition: Vol. 7B: Structures and Dynamics
,
Seoul, South Korea
,
June 13–17
, p.
V07BT34A008
.
28.
Placzek
,
A.
, and
Malher
,
A.
,
2012
, “
Efficient Coupling Strategies for the Numerical Prediction of the Aeroelastic Stability of Bladed Disks
,”
13th International Symposium on Unsteady Aerodynamics, Aeroacoustics and Aeroelasticity of Turbomachines (ISUAAAT 13)
,
Tokyo, Japan
,
Sept. 11–14
.
29.
He
,
L.
,
1992
, “
Method of Simulating Unsteady Turbomachinery Flows With Multiple Perturbations
,”
AIAA J.
,
30
(
11
), pp.
2730
2735
.
30.
Corral
,
R.
, and
Gallardo
,
J. M.
,
2014
, “
Nonlinear Dynamics of Bladed Disks With Multiple Unstable Modes
,”
AIAA J.
,
56
(
6
), pp.
1124
1132
.
31.
Crespo
,
J.
,
Coral
,
R.
, and
Pueblas
,
J.
,
2016
, “
An Implicit Harmonic Balance Method in Graphics Processing Units for Oscillating Blades
,”
ASME J. Turbomach.
,
138
(
3
), p.
031001
.
32.
Corral
,
R.
,
Escribano
,
A.
,
Gisbert
,
F.
,
Serrano
,
A.
, and
Vasco
,
C.
,
2003
, “
Validation of a Linear Multigrid Accelerated Unstructured Navier–Stokes Solver for the Computation of Turbine Blades on Hybrid Grids
,” 9th AIAA/CEAS Aeroacoustics Conference, Hilton Mead, SC, AIAA Paper No. 2003-3326.
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