Transcript Fluid-Structure Interaction Modelling with Europlexus Fast Dynamics Software S. Potapov

Fluid-Structure Interaction Modelling with
Europlexus Fast Dynamics Software
S. Potapov
EDF R&D – Analyses in Mechanics and Acoustics
Colloque GDR Interaction Fluide-Structure
Sophia
Antipolis, 26-27 September 2005
26-27 September 2005 Colloque GDR Intéraction Fluide-Structure, Sophia Antipolis
1
Outline
• Industrial context
• Numerical tool
• Incompatible FS interface
• Validation example
• Conclusion
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26-27 September 2005
Colloque GDR Intéraction Fluide-Structure, Sophia Antipolis
Loss Of Coolant Accident (LOCA)
GV1
GV4
GV2
Main Primary Circuit of PWR
GV3
Pipeline model
Générateur de vapeur (GV)
PP1
Branche
chaude (BC)
PP2
Cuve
Boucle 1
Pompe
primaire (PP)
Boucle 2
Boucle 4
Reactor vessel
Boucle 3
PP4
Cuve
PP3
Volume
sous couvercle
Branche en U (BU)
Branche froide (BF)
Ajutages
d'entrée
Mixed pipeline / 3D model
Ajutages
de sortie
Plenum
supérieur
PP
GV
Volume
d'entrée
Collecteur annulaire
anti-whipping
devices
break
Coeur
Dérivation coeur
Fond de cuve
1D/3D Fluid-Structure link
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Colloque GDR Intéraction Fluide-Structure, Sophia Antipolis
EUROPLEXUS fast dynamics code
(initiated by CEA in 1978, and developed jointly by CEA, JRC, EDF, SAMTECH since 2000)
Principal models available
for the FSI analysis:
Main characteristics:







transient phenomena (wave propagation)
fluids, structures and their interaction (FSI)
Lagrangian, Eulerian and ALE formulations
geometric and material non-linearities
1D, 2D, and 3D modelling (1D/3D connexions)
finite element formulation + transport terms
explicit time integration
 1D elements :
• pipes:
rigid and flexible
walls
• multi-pipe links:
• pump, break, local pressure losses
 3D fluid and structure elements
Domains of analysis:
1)
2)
3)
4)
5)
4
pipe circuits
hydrodynamics
explosions
impacts
robotics
26-27 September 2005
• tetrahedron, cube
• beam, plate, shell
• 1D-3D F and S connexions
Applications:
- nuclear reactors
- chemical plants
- off-shore structures
- submerged pipelines
- safety valves
 Compressible fluid materials:
Colloque GDR Intéraction Fluide-Structure, Sophia Antipolis
• gas (perfect)
• two-phase water
- homogeneous equilibrated
- steam tables
• pressure losses (distributed)
3D Fluid-Structure coupling in EUROPLEXUS
vF
Fluid
n
F
r
F
vS
S
Dynamic equilibrium over the whole domain:
-r
S
Structure
n
M ü = Fext - Fint
Kinematic links:
compatible
meshes
equality of
reactions
compatibility
condition
Cv=b
Equilibrium for the FS interface d.o.f.:
n
m n ü n = fext
- fintn + r n
For inviscid fluid:
vF .n = vS .n
Reactions at the FS interface:
r n = CT l
Incompatible FS interfaces:
Hierarchical type interface
Fluid
Structure
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(a)
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(b)
(c)
(d)
Colloque GDR Intéraction Fluide-Structure, Sophia Antipolis
Non-matching coupling conditions
v F  n  v S*  n
node
noeud
point
v F  n F  v S*  n F
v S*  i 1 NSi (S * ) v Si
n
v F  n F  [i 1 NSi (S * ) v Si ]  n F  0
n
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26-27 September 2005
Colloque GDR Intéraction Fluide-Structure, Sophia Antipolis
FSI simulation of LOCA accident in HDR
HeissDampfReaktor (KFA/ISR, Germany, 1980)
Experiment V32
Initial conditions:
(Superheated Steam Reactor)
break
Membrane
Blowdown
nozzle
Blowdown nozzle:
L = 1.37 m
Pressure
A = 0.0314 m2
vessel
Core barrel:
H = 7.57 m
R = 1.32 m
t = 0.023 m
Core
barrel
Downcomer
Mass ring
Lower plenum
Mass ring:
M = 13500 kg
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Colloque GDR Intéraction Fluide-Structure, Sophia Antipolis
water
P = 11 MPa
T = 300 °C
HDR model with EUROPLEXUS
Coarse mesh
Refinment
procedure
Fine mesh
Nb. of elements :
Fluid
: 35854
Structure: 2080
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Fluid
: 34204
Structure: 1148
Colloque GDR Intéraction Fluide-Structure, Sophia Antipolis
Structure
mesh
Fluid
mesh
Incompatible interface
Evolution of pressure
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P x 0.1 (MPa)
Colloque
GDR Intéraction Fluide-Structure, Sophia Antipolis
compatible
mesh
incompatible mesh
26-27 September 2005
P x 0.1 (MPa)
P x 0.1 (MPa)
Time histories of pressure and displacements
11,5
1,4
11,0
1,2
Experiment (Test V32)
Europlexus (matching meshes)
KS1002
10,5
Displacement (m)
Pressure (MPa)
Europlexus (non-matching meshes)
10,0
9,5
9,0
Experiment (Test V32)
Europlexus (matching meshes)
Europlexus (non-matching meshes)
BP9136
8,5
1,0
0,8
0,6
0,4
0,2
0,0
0
8,0
0
10
20
30
40
10
20
50
1,0
11,0
0,5
Displacement (m)
Pressure (MPa)
11,5
10,0
9,5
9,0
Experiment (Test V32)
Europlexus (matching meshes)
BP9140
8,5
0
10
10
20
30
40
50
26-27 September 2005
30
40
50
-1,0
KS1026
Experiment (Test V32)
Europlexus (matching meshes)
Europlexus (non-matching meshes)
-2,0
Time (ms)
10
20
-0,5
Europlexus (non-matching meshes)
0
50
0,0
-1,5
8,0
40
Time (ms)
Time (ms)
10,5
30
-0,2
Colloque GDR Intéraction Fluide-Structure, Sophia Antipolis
Time (ms)
Calculations with and without FSI
11,5
1,0
Differential pressure (MPa)
Pressure (MPa)
11,0
10,5
10,0
9,5
9,0
Experiment (Test V32)
Europlexus (FSI calculation)
Europlexus (rigid structure)
BP9133
8,5
0,5
0,0
0
10
40
50
40
50
-1,0
KP0032
Experiment (Test V32)
Europlexus (FSI calculation)
-1,5
Europlexus (rigid structure)
0
10
20
30
40
-2,0
50
Time (ms)
Time (ms)
1,0
11,5
Differential pressure (MPa)
11,0
Pressure (MPa)
30
-0,5
8,0
10,5
10,0
9,5
BP8302
9,0
Experiment (Test V32)
Europlexus (FSI calculation)
8,5
Europlexus (rigid structure)
0,5
0,0
0
10
20
30
-0,5
-1,0
-1,5
Experiment (Test V32)
Europlexus (FSI calculation)
Europlexus (rigid structure)
8,0
0
10
20
30
40
50
-2,0
Time (ms)
11
20
26-27 September 2005
Colloque GDR Intéraction Fluide-Structure, Sophia Antipolis
Time (ms)
KP0040
Time performance
Matching mesh:
Non-matching mesh:
Fluid:
35854 FE
Structure: 2080 FE
Fluid:
34204 FE
Structure: 1148 FE
on Compaq a
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Case
Mesh
type
Number of
elements
(F/S)
Nomber
of time
steps
CPU
time
[h]
CPU
time
ratio
Speedup
factor
A
Compatible
35854/2080
41981
216
25
1.00
-
B
Incompatible
34204/1148
15269
35
4
0.16
6.2
Colloque GDR Intéraction Fluide-Structure, Sophia Antipolis
Conclusion
13
•
The use of the new non-matching FS interface algorithm allows
realistic prediction of different physical phenomena characterising
the LOCA situation
•
This algorithm allows optimising physical modelling and mesh
generation for the fluid and structure domains
•
The CPU time is drastically reduced
26-27 September 2005
Colloque GDR Intéraction Fluide-Structure, Sophia Antipolis