1. CDT WP2 5th technical meeting Mol 05/2011 Vincent Moreau
FASTEF Primary pump/HX assembly update and preliminary tube rupture simulations
CDT meeting 01/2011 Brussel
CDT WP2 5th technical meeting Mol 05/2011
Vincent Moreau

2. Summary Design update Control Simulation Single bubble leak (1)
Simulation Results
Simulation/Design update
Single bubble leak (2)
Pump pre-design
Merging for large gas leak
What next
CDT meeting 01/2011 Brussel

3. Design update Addition of a chimney Enlarged pump casing
The initial and updated CAD design have been provided by Marco Ottolini
Addition of a chimney
Enlarged pump casing
Larger open volume below the HX
CDT meeting 01/2011 Brussel
The update has been the occasion to clean/simplify the flow diverter structure.

4. Design update Previous proposal First update
CDT meeting 01/2011 Brussel
Previous proposal
First update

5. Simulation: numerical setting
Default stationary setting
Inlet mass flow rate: 815 kg/s (total: 815x8=6520 kg/s, slightly too low, objective 7500 kg/s),
LBE density: kg/m3 (573K, HLM Handbook)
LBE viscosity: 1.84e-3 Pa.s
Realizable k-e turbulence model
Two-Layer All y+ Wall treatment
Passive scalar for residence time evaluation
Passive scalar source term (value=density) except in the HX
CDT meeting 01/2011 Brussel

6. Simulation Results
CDT meeting 01/2011 Brussel
Reasonable flow regulation with the radial separators obtained at the second trial

7. Simulation Results
CDT meeting 01/2011 Brussel
Bubble size issue: inlet velocity should be preserved
Also technical problems: forced to rebuild the geometry from scratch

8. Geometry update Equivalent inlet section Counter tube re-profiling
CDT meeting 01/2011 Brussel

9. Simulation Results Velocity magnitude and residence time
CDT meeting 01/2011 Brussel

10. Simulation Results Bubble injection from the HX tubes bottom
3 out of 50 2mm bubbles flow down to the propeller
CDT meeting 01/2011 Brussel

11. Simulation Results Bubble injection from the HX tubes bottom
1 out of 50 2mm bubbles flow down to the propeller
Critical zone located
CDT meeting 01/2011 Brussel

12. Include pump design
Need to include, even roughly, features of the pump current design (by Sebastien Mortier)
Upper diaphragm level Almost sealed
CDT meeting 01/2011 Brussel
Windows

13. Large gas leak Need to enlarge the simulation domain
Gas insertion forces LBE out
There are 4 possible outlets: 2 HXs, chimney and pump outlet.
Reaction of the 4 outlets also depend on the “far field”
An “almost” equivalent of the entire loop had to be built
CDT meeting 01/2011 Brussel

14. Large gas leak Enlarged simulation domain: Two half-HX
Large inner vessel volume
Core mockup (hydraulic resistance)
Large outer vessel volume
Remote handling volume
Volumetric force for the pump
CDT meeting 01/2011 Brussel

15. Large gas leak
Mesh
2MCells
Size 2-10cm

16. Large gas leak
Time needed to create the surface shift (days)

17. Large gas leak
Long transient to get a reasonable initial condition (25s)
LBE mass flow at beginning event: 1350 kg/s (should be 1750 kg/s)

18. Large gas leak Two different locations for the gas source Case 3
Case 1 and 2

19. Large gas leak Case 1: gas source 50 dm3/s in 1s exp ramp
Source location: tube basis, close to the inner wall
Physical time 4.5 s
Shown: iso-surface 0.5 of volumetric fraction

20. Large gas leak
Case 1, 50 dm3/s

21. Large gas leak Case 2: gas source 250 dm3/s in 1s exp ramp
Source location: tube basis, close to the inner wall
Physical time s
Shown: iso-surface 0.5 of volumetric fraction

22. Large gas leak
Case 2, 250 dm3/s

23. Large gas leak Case 3: gas source 50 dm3/s in 1s exp ramp
Source location: 12 cm over tube basis, close to the outer shell
Physical time 4.1 s
Shown: iso-surface 0.5 of volumetric fraction

24. Large gas leak
Case 3, 50 dm3/s

25. Large gas leak
Case 2 (250 l/s) Initial and final VM field

26. Large gas leak
Case 2 Pump mass flow history

27. Large gas leak
Case 2 Gas flow rate

28. Large gas leak What to do next:
Increase the LBE flow rate to 1750 kg/s
Test higher gas rate ?
Report ?

29. Thank you for your attention
End
Thank you for your attention
CDT meeting 01/2011 Brussel