study of the air temperature and velocity around the atlas muon chambers emma vigo castellvi st/cv...
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STUDY OF THE AIR TEMPERATURE STUDY OF THE AIR TEMPERATURE AND VELOCITY AROUND THE ATLAS AND VELOCITY AROUND THE ATLAS
MUON CHAMBERSMUON CHAMBERS
Emma Vigo CastellviST/CV Design
CONTENTS
• Situation of the Problem• Solution methodology (CFD)• Boundary Conditions• The Previous Model• The LMCh5 Model• The Closed Model• Conclusions
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
SITUATION OF THE PROBLEM
• Types:– BIS, BIL
– BMS, BML
– BOS, BOL
• Concerned by:–Temperature
–Air velocities
THE ATLAS BARREL MUON CHAMBERS
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
CONTENTS
• Situation of the Problem
• Solution methodology (CFD)
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
SOLUTION METHODOLOGY (CFD)
CFD (Computational Fluid Dynamic) is a method allowing to simulate on computer a wide range of phenomena linked to fluid mechanic (flow
analysis, thermodynamic, heat transfer...)
• Fluid mechanics equations numerically solved
• Domain splitted into cells
• Flow behaviour spatially uniform
• Physical gradients
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
cell+neighbours
discretisation or mesh
THE MESH
100’000 elements
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
CONTENTS
• Situation of the Problem
• Solution Methodology (CFD)
• Boundary Conditions
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
THE UX15 VENTILATION SYSTEMBOUNDARY CONDITIONS
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
BOUNDARY CONDITIONSTHE 2D “SECTION”
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
CONTENTS
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
• Situation of the Problem• Solution methodology (CFD)• Boundary Conditions
• The Previous Model
Results:• Quite optimistic• Middle axis chambers: most solicitated• Minor influence of the racks
Problems: • MDT’s heat load: 30mmW/channel• Not distributed inlet
THE PREVIOUS MODEL (LMCh3)
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
CONTENTS
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
• Situation of the Problem• Solution methodology (CFD)• Boundary Conditions• The Previous Model• The LMCh5 Model
NEWSLMCh5 MODEL
• Heat load of the MDTs’ electronics
• Distributed inlet
• Transient calculation
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
Ventilation Parameters
Air flow rate (m3/h) 60000
Inlet velocity (m/s) 0.085
Inlet air temperature (C) 17
Flow extracted by theupper unit (%) 78.95
Flow extracted by the unitin the pit (%) 21.05
BOUNDARY CONDITIONSLMCh5 MODEL
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
BOUNDARY CONDITIONSLMCh5 MODEL
Thermal Loads
BOS, BOL 21.7 W/m * 33.5 W/m2
BML 21.7 W/m* 29.38 W/m2
BMS 21.7 W/m* 33.16 W/m2
BIS 21.7 W/m* 76.84 W/m2
BIL, BIR 21.7 W/m* 52.1 W/m2
Electronic Racks 20 W/m 3.45 W/m2
RPC: BOL BOS BML BMS
28 W24 W20 W18 W
5 W/m2
Tile BarrelCalorimeter
- 8 W/m2
Barrel Coils -10 W/m -3.98 W/m2
(*) corresponding to 65mW/channel
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
6000sec : TEMPERATURE MAPLMCh5 MODEL
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
6000sec : VELOCITY MAPLMCh5 MODEL
CONTENTS
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
• Situation of the Problem• Solution methodology (CFD)• Boundary Conditions• The Previous Model• The LMCh5 Model
• The Closed Model
WHAT’S NEXT?
• Gaps between chambers: closed + porosity
• MCh: solids with conduction
• RPC’s non conducting heating surfaces
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
Status:- Geometry completely finished- Geometry successfully transferred to StarCD- At present: definition of new boundary conditions
CMCh MODEL
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
CONTENTS
• Situation of the Problem• Solution methodology (CFD)• Boundary Conditions• The Previous Model• The LMCh5 Model• The Closed Model• Conclusions
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
CONCLUSIONS
• Global understanding of the case study
• Velocity doesn’t reach high values
• Temperature gradients could be over the constraints
• Medium axis chambers: most solicitated
• Closed Muon Chambers (CMCh) study being donebeing done
• Next stepNext step: 3D simplified model
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
STUDY OF THE AIR TEMPERATURE STUDY OF THE AIR TEMPERATURE AND VELOCITY AROUND THE ATLAS AND VELOCITY AROUND THE ATLAS
MUON CHAMBERSMUON CHAMBERS
Emma Vigo CastellviST/CV Design
Study of the Air Temperature and Velocity Around the ATLAS Muon Chambers Emma Vigo, ST/CV, 15 October 2001
See also: http://evigocas.home.cern.ch/evigocas/atlas_air_flow.html