Coupling of Cable FEA Solution With 6 DOF CFD Solution for Subsea Equipment Launching Simulation Fabio Saltara Roberto Monteiro Basto da Silva Ricardo Barbosa Damian Ismael Lis Alves Daoud Armando Alvarez de Souza Regis Ataides
Coupling of Cable FEA Solution With 6 DOF CFD Solution for Subsea Equipment Launching Simulation
Fabio Saltara Roberto Monteiro Basto da Silva Ricardo Barbosa Damian Ismael Lis Alves Daoud Armando Alvarez de Souza Regis Ataides
Company Overview - ESSS
ESSS gathers the engineering and computer science knowledge necessary
to deliver a complete range of mathematical modeling and numerical
simulation solutions to a wide spectrum of industries. A highly-skilled team of
engineers and software developers is always ready to offer the world’s most
comprehensive CAE software and a full portfolio of services focused on in-
house development, consulting, customization, technical support and
training.
The combination of added-value services and high performance tools makes
ESSS a leading provider of solutions for faster, better and more cost-efficient
product development.
Problem Description
Subsea Equipment Launching Simulation
Alternatives:
- AQWA-FLUENT coupling
- Structural ANSYS – FLUENT coupling
- FLUENT User Defined Function (UDF) Solution
Problem Description
Methodology – FEA Solution
cablesdragbuoyancyweightmassaddedinertia FFFFFF
cablesdragdAA
a FFgmmt
tdttdmm
2
ma = added mass
md = displaced fluid mass
Methodology – FEA Solution (2D Formulation)
yneighbour
xneighbour
yA
xA
o
d
d
d
d
mlmmlm
lmllml
L
EAdK
22
22
L
xxl
L
yym
AneighbourAneighbour
L
txtx
L
LLEAFgmmttdK
t
tdttdmm
Aneighbour
cables o
odragd
cables
AAa
)()(
2
Where:
Methodology – 6DOF and FEA Coupling
connectors
bodyichydrodynamext TgmFF
connectors
ichydrodynamext TrMM
,,,6
CGCGDOF
xx
trxd CGconnectors
Case 1
Case 1
26,022 cells
11,622 triangular cells
14,400 quadrilateral cells
t=0.01 s
Spalart-Allmaras Turbulence
Model
Final Time: 118 s
Boundary Conditions
Deforming + Remeshing Methodology
- After five time-steps the triangular cells are remeshed;
- At each time-steps the mesh is deformed according to a displacement diffusion methodology:
.boundarynearestthetodistancetheisawhere,1
;velocitymeshtheiswhere
0
2a
W
x
W
x
i
j
i
j
Results - Case 1
Results - Case 1
Case 2
Final time around 265 s. Mesh and other settings are the same of Case 1.
Results - Case 2
Results - Case 2
Conclusion
It was demonstrated that it is possible to use a FLUENT User Defined Function (UDF) for the FEA solution of the cable forces and displacements during the simulation of the pendulum motion that is a feature of the launching of subsea equipment and it is feasible to run a full CFD simulation of this type of operation.
Next Steps
• Development of the full 3D methodology ( involves only changing the [K] matrix );
• Evaluation of other turbulence models;
• Evaluation of other moving mesh methodology (could all mesh be considered as having rigid body motion?);
• Parallelization of the UDF;
• Mesh generation for a 3D case.