1. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation1M. Battistin TS/CV/Detector Cooling - CFD Team CERN June 24 th 2005 Michele Battistin CERN presentation & CFD at CERN

2. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation2M. Battistin 09.30 CERN presentation 09.45 CFD activity presentation 11.15 visit to the computer center 513 (Andreas Hirstius tel: 74503) 12.00 visit to ATLAS cavern (Geoffrey Tappern tel: 164566) 13.00 lunch 14.00-16.00 discussions AGENDA

3. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation3M. Battistin CERN European Organization for Nuclear Research Founded in 1954 by 12 countries Today: 20 member states More than 7000 users from all over the world ~1000 MCHF / Year budget 1954: Convention establishing the Organization - original signatures2004: The 20 member states

4. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation4M. Battistin Why accelerators? To investigate Particle Physics Particle physics looks at matter in its smallest dimensions AcceleratorsMicroscopes Optical and radio telescopes Binoculars

5. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation5M. Battistin What happened an instant after the Big Bang?

6. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation6M. Battistin How can we go back the time? 15 Billions of years 5 Billions of years 1 Billion of years 330.000 years 100 seconds 0.1 Nanoseconds (10 -10 ) 10 -34 seconds 10 -43 seconds PS (’59) LEP (’89) LHC (’07) ACCELERATOR ENERGY

7. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation7M. Battistin The “bricks” of the matter

8. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation8M. Battistin We don't know everything! Why three generations? Supersymmetry? Higgs boson? The LHC will help solving all these unsolved mysteries

9. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation9M. Battistin 3) Identify created particles in Detector (search for new clues) 1) Concentrate energy on particles (accelerator) 2) Collide particles (recreate conditions after Big Bang) Methods of particle physics

10. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation10M. Battistin acceleratore LHC CERN sito principale acceleratore SPS CERN secondo sito CERN accelerators structure

11. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation11M. Battistin LHC Large Hadron Collider 1230 magnets will be installed in the 27 km long tunnel - They will run at -271˚C

12. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation12M. Battistin ATLAS Alice LHCb CMS LHCb At 4 points the particles are forced to collide

13. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation13M. Battistin Detectors are used to “take a picture” to the particles

14. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation14M. Battistin Higgs signature at the LHC We expect only 1 Higgs in 1,000,000,000,000 events The two proton beams at the LHC will collide head-on 800 million times per second

15. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation15M. Battistin Moore’s law Jan 2000: 3.5K SI95 LHC experiments Other experiments Evolution of CERN computing needs CPU capacity 1998-2010

16. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation16M. Battistin The GRID: a possible solution to CERN computing needs The LHC computing GRID is a project funded by the European Union. The objective is to build the next generation computing infrastructure providing intensive computation and analysis

17. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation17M. Battistin Computational Fluid Dynamic Team at CERN

18. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation18M. Battistin

19. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation19M. Battistin CFD team mission The mandate of this team is to provide assistance to the LHC experiments in the design and prototype phase and support all other CERN units too. CERN mandate is also to give training opportunity to students and young professionals (especially i the physics, engineering and computer science fields) coming form the member states to spread then, this knowledge in the origin states. The Team has formed tens of engineers to CFD in since last 12 years.

20. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation20M. Battistin CFD team resources 6 young engineers coming form the member states for short medium periods (6 months – 3 years) Engineering PC Pentium 4 - 2 GRam - 2,8 GHz for development A cluster of 20 Itanium 64 bit, double CPU machine for calculation Limited access to a larger Itanium cluster (OpenLab) ADAPCO ® StarCD software licenses 12 development licenses 104 calculation licenses

21. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation21M. Battistin CFD project in 2004-2005  Model dimension is a compromise between accuracy and time to result  Most of the projects take between 1 week and 1 month of calculation time per case  A project last between 1 and 4 months

22. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation22M. Battistin Back-up slides

23. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation23M. Battistin CNGS Horn Air Cooling CFD simulations helped to decide modifications even during the construction phase Particle energy deposition heats up the horn and its shielding structure

24. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation24M. Battistin CFD for safety too Cavern floor: where some person could be present Velocity iso-surfaces

25. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation25M. Battistin Alice Muons Detector heat transfer

26. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation26M. Battistin Inner Trackers: no time for prototypes At CERN, most of the times, the final system is the prototype. CFD can provide insight into fluid flow problems when experimental techniques are too expensive or physically impossible. The Alice, ATLAS and CMS Inner Trackers are good examples.

27. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation27M. Battistin SPS magnetLHCb PS/SPD Who performs these simulations

28. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation28M. Battistin

29. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation29M. Battistin

30. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation30M. Battistin From fluid dynamics to Computational Fluid Dynamics What is CFD Industrial and CERN applications The CFD service team at CERN Opportunities What future for this team?

31. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation31M. Battistin Duration of a study  Model dimension is a compromise between accuracy and time to result  Most of the projects take between 1 week and 1 month of calculation time per case  A project has an average of 6 cases Apr-Dec 2004

32. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation32M. Battistin CFD equations Equation of mass conservation Equations of momentum conservation (Navier-Stokes) Equation of energy conservation + 2 equations of k-ε model of turbulence (differential) Equation of state: ideal gas + Boundary and initial conditions

33. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation33M. Battistin …specific knowledge is required Efficiency to build the right model Selection of the right numerical solver Sensibility to result interpretation …training …experience …knowledge and problem sharing

34. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation34M. Battistin New project Problem definition Numerical Analysis Request document issued and approved (EDMS) Numerical Analysis Evolution Final Report Results Procedure on EDMS 459266

35. TS/CV/DC CFD Team June 2005 – CERN & CFD Presentation35M. Battistin CFD is useful in many fields at CERN Natural and forced convection heat transfer ATLAS Muons chambers, ALICE L3 ventilation, ALICE Muons Some chamber need an additional cooling source: a thermal screen will be implemented Air cooling CNGS Horn and Reflector air cooling analysis, LHCb electronics cooling. Bdg 513 ventilation of the grid computer room. Additional gaps in the shielding walls, trenches on the target chamber floor Water cooling SPS magnet cooling analysisExact definition of the heat power evacuated by cooling water and air Safety CNGS tunnel: flow analysis in case of decay tunnel cap rupture. The Globe: fire effect simulation, transient temperature distribution. Special duct installation to resist to high pressure and move the high speed point in a safe zone of ECA4 cavern Gas distribution ATLAS Inner Tracker CO 2 and N 2 flow analysis. Flushing time estimation before cooling Definition of the inlet points position and the time to complete the flush. Humidity distribution CMS Tracker flow analysis.Reduction of inlet points from 8 to 1.