Deepwater risers are susceptible to vortex-induced vibrations (VIV) when subjected to currents. When responding at high modes, fatigue damage in the inline (IL) direction may become equally important as the crossflow (CF) components. Accurate calculation of both IL and CF responses is therefore needed. Empirical VIV prediction programs, such as VIVANA “Passano et al. (2016, “VIVANA—Theory Manual Version 4.8,” Trondheim, Norway),” SHEAR7 “(Vandiver, J. K., and Li, L., 2007, “Shear7 v4.5 Program Theoretical Manual,” Department of Ocean Engineering, Massachusetts Institute of Technology, Cambridge, MA),” and VIVA “Triantafyllou et al. (1999, “Pragmatic Riser VIV Analysis,” Offshore Technology Conference, Houston, TX, May 3–6, Paper No. OTC-10931-MS.)” are the most common tools used by the offshore industry. Progress has been seen in the prediction of CF responses. Efforts have also been made to include an IL load model in VIVANA. A set of excitation coefficient parameters were obtained from rigid cylinder test and adjusted using measured responses of one of the flexible cylinder VIV tests. This set of excitation coefficient parameters is still considered preliminary and further validation is required. Without an accurate IL response prediction, a conservative approach in VIV analysis has to be followed, i.e., all current profiles have to be assumed to be unidirectional or acting in the same direction. The purpose of this paper is to provide a reliable combined IL and CF load model for the empirical VIV prediction programs. VIV prediction using the existing combined IL and CF load model in VIVANA is validated against selected flexible cylinder test data. A case study of a deepwater top tension riser (TTR) has been carried out. The results indicate that VIV fatigue damage using two-dimensional directional current profiles is less conservative compared to the traditional way of using unidirectional current profiles.

References

References
1.
Passano
,
E.
,
Larsen
,
C. M.
,
Lie
,
H.
, and
Wu
,
J.
,
2016
, “
VIVANA—Theory Manual Version 4.8
,” Trondheim, Norway.
2.
Vandiver
,
J. K.
, and
Li
,
L.
,
2007
, “
Shear7 v4.5 Program Theoretical Manual
,” Department of Ocean Engineering, Massachusetts Institute of Technology, Cambridge, MA.
3.
Triantafyllou
,
M.
,
Triantafyllou
,
G.
,
David Tein
,
Y. S.
, and
Ambrose
,
B. D.
,
1999
, “
Pragmatic Riser VIV Analysis
,”
Offshore Technology Conference
,
Houston, TX
,
May 3–6
, Paper No.
OTC-10931-MS
.
4.
Srivilairit
,
T.
, and
Manuel
,
L.
,
2009
, “
Vortex-Induced Vibration and Coincident Current Velocity Profiles for a Deepwater Drilling Riser
,”
ASME J. Offshore Mech. Arct. Eng.
,
131
(
2
), p. 021101.
5.
Passano
,
E.
,
Lie
,
H.
, and
Larsen
,
C. M.
, 2012, “
Comparison of Calculated In-Line Vortex Induced Vibrations to Model Tests
,”
ASME
Paper No. OMAE2012-83387.
6.
Chaplin
,
J. R.
,
Bearman
,
P. W.
,
Huera Huarte
,
F. J.
, and
Pattenden
,
R. J.
,
2005
, “
Laboratory Measurements of Vortex-Induced Vibrations of a Vertical Tension Riser in a Stepped Current
,”
J. Fluids Struct.
,
21
(
1
), pp.
3
24
.
7.
Huse
,
E.
,
Kleiven
,
G.
, and
Nielsen
,
F. G.
,
1998
, “
Large Scale Model Testing of Deep Sea Risers
,”
Offshore Technology Conference
,
Houston, TX
,
May 4–7
,
Paper No. OTC-8701-MS
.
8.
Trim
,
A. D.
,
Braaten
,
H.
,
Lie
,
H.
, and
Tognarelli
,
M. A.
,
2005
, “
Experimental Investigation of Vortex-Induced Vibrations of Long Marine Risers
,”
J. Fluids Struct.
,
21
(
3
), pp.
335
361
.
9.
Baarholm
,
G. S.
,
Larsen
,
C. M.
, and
Lie
,
H.
,
2006
, “
Effect of Strakes on Fatigue Damage Due to Cross-Flow VIV
,”
Third International Conference on Hydroelasticity in Marine Technology
,
Wuxi, China
,
Sept. 10–14
.
10.
Bourguet
,
R.
,
Karniadakis
,
G. E.
, and
Triantafyllou
,
M. S.
,
2013
, “
Phasing Mechanisms Between the In-Line and Cross-Flow Vortex-Induced Vibrations of a Long-Tensioned Beam in Shear Flow
,”
J. Comput. Struct.
,
122
, pp.
155
163
.
11.
Venugopal
,
M.
,
1996
, “
Damping and Response Prediction of a Flexible Cylinder in a Current
,”
Ph.D. thesis
, Massachusetts Institute of Technology, Cambridge, MA.https://dspace.mit.edu/handle/1721.1/11279
12.
Gopalkrishnan
,
R.
,
1992
,
Vortex-Induced Forces on Oscillating Bluff Cylinders
,
Massachusetts Institute of Technology
,
Cambridge, MA
.
13.
Wu
,
J.
,
Lie
,
H.
,
Larsen
,
C. M.
,
Liapis
,
S.
, and
Baarholm
,
R.
,
2016
, “
Vortex-Induced Vibration of a Flexible Cylinder: Interaction of the In-Line and Cross-Flow Responses
,”
J. Fluids Struct.
,
63
, pp.
238
258
.
14.
Dahl
,
J. J. M.
,
2008
, “
Vortex-Induced Vibration of a Circular Cylinder With Combined In-Line and Cross-Flow Motion
,”
Ph.D. thesis
, MIT Institute of Technology, Cambridge, MA.https://dspace.mit.edu/handle/1721.1/44747
15.
Soni
,
P. K.
,
2008
, “
Hydrodynamic Coefficients for Vortex-Induced Vibrations of Flexible Beams
,” Norwegian University of Science and Technology, Trondheim, Norway.
16.
Yin
,
D.
,
2013
, “
Experimental and Numerical Analysis of Combined In-Line and Cross-Flow Vortex Induced Vibration
,”
Ph.D. thesis
, Norwegian University of Science and Technology, Trondheim, Norway.https://brage.bibsys.no/xmlui/handle/11250/273121
17.
Wu
,
J.
,
2011
, “
Hydrodynamic Force Identification From Stochastic Vortex Induced Vibration Experiments With Slender Beams
,”
Ph.D. thesis
, Norwegian University of Science and Technology, Trondheim, Norway.https://brage.bibsys.no/xmlui/handle/11250/237910
18.
Wu
,
J.
,
Larsen
,
C. M.
, and
Lie
,
H.
,
2010
, “
Estimation of Hydrodynamic Coefficients for VIV of Slender Beam at High Mode Orders
,”
ASME
Paper No. OMAE2010-20327.
19.
Voie
,
P.
,
Wu
,
J.
,
Larsen
,
C. M.
,
Resvanis
,
T.
,
Vandiver
,
J. K.
, and
Triantafyllou
,
M.
,
2017
, “
Consolidated Guideline on Analysis of Vortex-Induced Vibrations in Risers and Umbilicals
,”
ASME
Paper No. OMAE2017-61362.
20.
Baarholm
,
G.
,
Larsen
,
C. M.
, and
Lie
,
H.
,
2006
, “
On Fatigue Damage Accumulation From In-Line and Cross-Flow Vortex-Induced Vibrations on Risers
,”
J. Fluids Struct.
,
22
(
1
), pp.
109
127
.
21.
Brodtkorb
,
P. A.
,
Johannesson
,
P.
,
Lindgren
,
G.
,
Rychlik
,
I.
,
Ryden
,
J.
, and
Sjö
,
E.
,
2000
, “
WAFO—A Matlab Toolbox for Analysis of Random Waves and Loads—A Tutorial
,” Lund University, Lund, Sweden.
22.
Passano
,
E.
,
Larsen
,
C. M.
, and
Wu
,
J.
,
2014
, “
On Prediction of Fatigue Damage From VIV
,”
ASME
Paper No. OMAE2014-24217.
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