The aerodynamic impact of installing a horizontal pylon in front of a contra-rotating open rotor engine, at take-off, was studied. The unsteady interactions of the pylon's wake and potential field with the rotor blades were predicted by full-annulus URANS CFD calculations at 0 deg and 12 deg angle of attack (AoA). Two pylon configurations were studied: one where the front rotor blades move down behind the pylon (DBP), and one where they move up behind the pylon (UBP). When operating at 12 deg AoA, the UBP orientation was shown to reduce the rear rotor tip vortex sizes and separated flow regions, whereas the front rotor wake and vortex sizes were increased. In contrast, the DBP orientation was found to reduce the incidence variations onto the front rotor, leading to smaller wakes and vortices. The engine flow was also time-averaged, and the variation in work done on average midspan streamlines was shown to depend strongly on variation in incidence, along with a smaller contribution related to change of radius.

References

References
1.
Ricouard
,
J.
,
Julliard
,
E.
,
Omaïs
,
M.
,
Regnier
,
V.
,
Parry
,
A. B.
, and
Baralon
,
S.
,
2010
, “
Installation Effects on Contra-Rotating Open Rotor Noise
,”
AIAA
Paper No. 2010-3795.
2.
Boisard
,
R.
,
Delattre
,
G.
, and
Falissard
,
F.
,
2014
, “
Computational Fluid Dynamics as a Support to Counter-Rotating Open-Rotor Wind-Tunnel Test Analysis
,”
J. Aircr.
,
51
(
2
), pp.
614
628
.
3.
Stürmer
,
A.
,
Yin
,
J.
, and
Akkermans
,
R.
,
2014
, “
Progress in Aerodynamic and Aeroacoustic Integration of CROR Propulsion Systems
,”
Aeronaut. J.
,
118
(
1208
), pp.
1137
1158
.
4.
Colin
,
Y.
,
Wlassow
,
F.
,
Caruelle
,
B.
,
Nodé-Langlois
,
T.
,
Omaïs
,
M.
,
Spiegel
,
P.
, and
Parry
,
A. B.
,
2014
, “
Installation Effects on Contra-Rotating Open Rotor Noise at High-Speed
,”
AIAA
Paper No. 2014-2971.
5.
Sohoni
,
N. G.
,
Hall
,
C. A.
,
Brandvik
,
T.
, and
Parry
,
A. B.
,
2015
, “
Prediction and Measurement of Unsteady Blade Surface Pressures on an Open Rotor
,”
ASME
Paper No. GT2015-42334.
6.
Paquet
,
C.
,
Julliard
,
E.
,
Ricouard
,
J.
, and
Spiegel
,
P.
,
2014
, “
Z08: Low-Speed Aero-Acoustic Experimental Characterization of Open Rotor Installation on Aircraft
,”
AIAA
Paper No. 2014-2747.
7.
Brandvik
,
T.
, and
Pullan
,
G.
,
2011
, “
An Accelerated 3D Navier–Stokes Solver for Flows in Turbomachines
,”
ASME J. Turbomach.
,
133
(
2
), p.
021025
.
8.
Denton
,
J. D.
,
1983
, “
An Improved Time-Marching Method for Turbomachinery Flow Calculation
,”
ASME J. Eng. Gas Turbines Power
,
105
(
3
), pp.
514
521
.
9.
Jameson
,
A.
,
1991
, “
Time Dependent Calculations Using Multigrid, With Applications to Unsteady Flows past Airfoils and Wings
,”
AIAA
Paper No. 91-1596.
10.
Jameson
,
A.
,
Schmidt
,
W.
, and
Turkel
,
E.
,
1981
, “
Numerical Solutions of the Euler Equations by Finite Volume Methods Using Runge-Kutta Time-Stepping Schemes
,”
AIAA
Paper No. 81-1259.
11.
Spalart
,
P. R.
, and
Allmaras
,
S. R.
,
1994
, “
A One-Equation Turbulence Model for Aerodynamic Flows
,”
Rech. Aerosp.
,
1
, pp.
5
21
.
12.
Loring
,
B.
,
2013
, “
Line Integral Convolution in ParaView
,” Kitware, Inc., New York, accessed June 6, 2016, https://web.archive.org/web/20160606023821/http://www.paraview.org/Wiki/ParaView/Line_Integral_Convolution
13.
Cabral
,
B.
, and
Leedom
,
L. C.
,
1993
, “
Imaging Vector Fields Using Line Integral Convolution
,”
20th Annual Conference on Computer Graphics and Interactive Techniques—SIGGRAPH
, Anaheim, CA, Aug. 2–6, pp. 263–270.
14.
Laramee
,
R.
,
Jobard
,
B.
, and
Hauser
,
H.
,
2003
, “
Image Space Based Visualization of Unsteady Flow on Surfaces
,”
IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control, pp. 131–138
.
15.
Gonzalez-Martino
,
I.
,
Francois
,
B.
, and
Rodriguez
,
B.
,
2014
, “
A Numerical Insight Into Contra-Rotating Open Rotor in-Plane Loads
,”
Mech. Ind.
,
15
(
1
), pp.
19
28
.
16.
Zachariadis
,
A.
,
Hall
,
C. A.
, and
Parry
,
A. B.
,
2013
, “
Contrarotating Open Rotor Operation for Improved Aerodynamics and Noise at Takeoff
,”
ASME J. Turbomach.
,
135
(
3
), p.
031010
.
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