The main role of the intake is to provide a sufficient mass flow to the engine face and a sufficient flow homogeneity to the fan. Intake-fan interaction off design represents a critical issue in the design process because intake lines are set very early during the aircraft optimization. The offdesign operation of an aero-engine, strictly related to the intake flow field, can be mainly related to two different conditions. When the plane is in near ground position, vorticity can be ingested by the fan due to crosswind incidence. During the flight, distortions occur due to incidence. In these conditions, the windward lip is subjected to high acceleration followed by strong adverse pressure gradients, high streamline curvature, and cohabitation of incompressible and transonic flow around the lip. All these features increase the risk of lip stall in flight at incidence or in crosswind near ground operation and increase the level of forcing seen by the fan blades because of the interaction with nonuniform flow from the intake. This work deals with the study of two sources of distortions: ground vortex ingestion and flight at high incidence conditions. A test case representative of a current installation clearance from the ground has been investigated and the experimental data available in open literature validated the computational fluid dynamics (CFD) calculations. An intake, representative of a realistic civil aero-engine configuration flying at high incidence, has been investigated in powered and aspirated configurations. Distortion distributions have been characterized in terms of total loss distributions in space and in time. The beneficial effect of the presence of fan in terms of distortion control has been demonstrated. The mutual effect between fan and incoming distortion from the intake has been assessed in terms of modal force and distortion control. CFD has been validated by means of comparisons between numerical results and experimental data which have been provided. Waves predicted by CFD have been compared with an actuator disk approach prediction. The linear behavior of the lower disturbance frequency coming from distortion and the waves reflected by the fan has been demonstrated.

References

References
1.
Peters
,
A.
,
Spakonvsky
,
Z.
,
Lord
,
W. K.
, and
Rose
,
B.
,
2014
, “
Ultrashort Nacelles for Low Fan Pressure Ratio Propulsors
,”
ASME J. Turbomach
,
137
(
2
), p.
021001
.
2.
Rife
,
M. E.
,
Parry
,
A. B.
, and
di Mare
,
L.
,
2015
, “
Fan Response Reduction Through Bypass Outlet Guide Vane Optimisation
,” Paper No. I14-S4-2.
3.
Klein
,
H.
,
1985
, “
Small Scale Tests on Jet Engine Pebble Aspiration Tests
,” Douglas Aircraft Company, Report No. SM-14885.
4.
De Siervi
,
F.
,
1982
, “
Mechanisms of Inlet-Vortex Formation
,”
J. Fluid Mech.
,
124
(
1982
), pp.
173
207
.
5.
Liu
,
W.
,
Greitzer
,
E. M.
, and
Tan
,
C. S.
,
1985
, “
Surface Static Pressures in an Inlet Vortex Flow Field
,”
ASME J. Eng. Gas Turbines Power
,
107
(
2
), pp.
387
393
.
6.
Ho
,
W. H.
,
Dumbleton
,
H.
, and
Jermy
,
M. C.
,
2008
, “
Effect of Upstream Velocity Gradient on the Formation of Sink Vortices in a Jet Engine Test Cell
,”
International MultiConference of Engineers and Computer Scientists
, Hong Kong, Mar. 19–21, Vol.
2
.
7.
Murphy
,
J. P.
, and
MacManus
,
D. G.
,
2011
, “
Inlet Ground Vortex Aerodynamics Under Headwind Conditions
,”
Aerosp. Sci. Technol.
,
15
(
3
), pp.
207
215
.
8.
Murphy
,
J. P.
, and
MacManus
,
D. G.
,
2011
, “
Intake Ground Vortex Prediction Methods
,”
J. Aircr.
,
48
(
1
), pp.
23
33
.
9.
Xie
,
H.
,
Wu
,
Y.
,
Wang
,
A.
, and
Ouyang
,
H.
,
2014
, “
Numerical Investigation of Crosswind Effect on Different Rear Mounted Engine Installations
,”
ASME
Paper No. GTINDIA2014-8171.
10.
di Mare
,
L.
,
Simpson
,
G.
, and
Sayma
,
A. I.
,
2006
, “
Fan Forced Response Due to Ground Vortex Ingestion
,”
ASME
Paper No. GT2006-90685.
11.
Green
,
J. S.
,
2008
, “
Forced Response of a Large Civil Fan Assembly
,”
ASME
Paper No. GT2008-50319.
12.
Glenny
,
D. E.
,
1970
, “
Ingestion of Debris Into Intake by Vortex Action
,” Aeronautical Research Council Paper No. 1114 1970.
13.
Hall
,
Cesare
,
A.
, and
Hynes
,
T. P.
,
2006
, “
Measurements of Intake Separation Hysteresis in a Model Fan and Nacelle Rig
,”
J. Propul. Power
,
22
(
4
), pp.
872
879
.
14.
Xie
,
H.
,
Wu
,
Y.
,
Wang
,
A.
, and
Ouyang
,
H.
,
2015
, “
Numerical Investigation of Inlet Distortion for Different Rear Mounted Engine Installations at Taking-Off Conditions
,”
ASME
Paper No. GT2015-42350.
15.
Kennedy
,
S.
,
Robinson
,
T.
,
Spence
,
S.
, and
Richardson
,
J.
,
2014
, “
Computational Investigation of Inlet Distortion at High Angles of Attack
,”
J. Aircr.
,
51
(
2
), pp.
361
376
.
16.
Carnevale
,
M.
,
Wang
,
F.
,
Green
,
J. S.
, and
di Mare
,
L.
,
2016
, “
Lip Stall Suppression in Powered Intake
,”
ASME J. Propuls. Power
,
32
(
1
), pp.
161
170
.
17.
Boldman
,
D. R.
,
Hwang
,
D. P.
,
Larkin
,
M.
, and
Schweiger
,
P.
,
1993
, “
Effect of a Rotating Propeller on the Separation Angle of Attack and Distortion in Ducted Propeller Inlets
,” NASA Technical Memorandum No. 105935, AIAA-93-0017.
18.
Romanov
,
A.
, and
di Mare
,
L.
,
2013
, “
Extended Turbomachinery Aeromechanical Model
,”
ASME
Paper No. GT2013-95667.
19.
di Mare
,
L.
,
Davendu
,
Y. K.
,
Wang
,
F.
,
Romanov
,
A.
,
Ramar
,
P. R.
, and
Zachariadis
,
I. Z.
,
2011
, “
Virtual Gas Turbines: Geometry and Conceptual Description
,”
ASME
Paper No. GT2011-46437.
20.
Carnevale
,
M.
,
Green
,
J. S.
, and
di Mare
,
L.
,
2014
, “
Numerical Studies Into Intake Flow for Fan Forcing Assessment
,”
ASME
Paper No. GT2014-25772.
21.
Roe
,
P. L.
,
1981
, “
Approximate Riemann Solvers, Parameter Vectors and Difference Schemes
,”
J. Comput. Phys.
,
43
(
2
), pp.
357
372
.
22.
Van Leer
,
B.
,
1982
, “
Flux Splitting for the Euler Equation
,”
8th International Conference on Numerical Methods in Fluid Dynamics
, Aachen, Germany, June 28–July 2, pp.
507
512
.
23.
Liou
,
M.-S.
,
2006
, “
A Sequel to AUSM, Part II: AUSM+-up
,”
J. Comput. Phys.
,
214
(
1
), pp.
137
170
.
24.
Choi
,
Y. H.
, and
Merkle
,
C. L.
,
1993
, “
The Application of Precondition in Viscous Flow
,”
J. Comput. Phys.
,
105
(
2
), pp.
207
223
.
25.
Wilcox
,
D. C.
,
1988
, “
Re-Assessment of the Scale-Determining Equation for Advanced Turbulence Models
,”
AIAA J.
,
26
(
11
), pp.
1299
1310
.
26.
Cumpsty
,
N. A.
, and
Marble
,
F. E.
,
1977
, “
The Interaction of Entropy Fluctuations With Turbine Blade Rows; A Mechanism of Turbojet Engine Noise
,”
Proc. R. Soc. London A
,
357
(
1690
), pp.
323
344
.
27.
Kaji
,
S.
, and
Okazaki
,
T.
,
1970
, “
Propagation of Sound Waves Through a Blade Row
,”
J. Sound Vib.
,
11
(
3
), pp.
339
353
.
28.
Cumpsty
,
N. A.
, and
Storer
,
J. A.
,
1994
, “
An Approximate Analysis and Prediction Method for Tip Clearance Loss in Axial Compressors
,”
ASME J. Turbomach.
,
116
(
4
), pp.
648
656
.
29.
Wright
,
P. I.
, and
Miller
,
D. C.
,
1991
, “
An Improved Compressor Performance Prediction Model
,”
IMechE
,
C423/028
, pp.
69
82
.
30.
König
,
W. M.
,
Hennecke
,
D. K.
, and
Fottner
,
L.
,
1996
, “
Improved Blade Profile Loss and Deviation Angle Models for Advanced Transonic Compressor Bladings: Part I—A Model for Subsonic Flow
,”
ASME J. Turbomach.
,
118
(
1
), pp.
73
80
.
31.
Bernardini
,
C.
,
Carnevale
,
M.
,
Salvadori
,
S.
, and
Martelli
,
F.
,
2011
, “
On the Assessment of an Unstructured Finite-Volume DES/LES Solver for Turbomachinery Application
,”
WSEAS Trans. Fluid Mech.
,
6
, pp.
160
173
.
32.
Bernardini
,
C.
,
Carnevale
,
M.
,
Manna
,
M.
,
Martelli
,
F.
,
Simoni
,
D.
, and
Zunino
,
P.
,
2012
, “
Turbine Blade Boundary Layer Separation Suppression Via Synthetic Jet: An Experimental and Numerical Study
,”
J. Therm. Sci.
,
21
(
5
), pp.
404
412
.
33.
Carnevale
,
M.
,
Montomoli
,
F.
,
D'Ammaro
,
A.
,
Salvadori
,
S.
, and
Martelli
,
F.
,
2013
, “
Uncertainty Quantification: A Stochastic Method for Heat Transfer Prediction Using LES
,”
J. Turbomach.
,
135
(
5
), p.
051021
.
34.
Wang
,
F.
,
Carnevale
,
M.
,
Lu
,
G.
, and
di Mare
,
L.
,
2016
, “
A Preprocessing Method for Large Scale Gas Turbine Numerical Simulations
,”
ASME
Paper No. GT2016-56227.
You do not currently have access to this content.