6 th september 20061s. eicher, m. battistin upgrade thermal management workshop september 6 th 2006...
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6 th September 20063S. Eicher, M. Battistin Moisture Removal in the CMS TOB with Nitrogen (Nicola Gatti, EDMS )TRANSCRIPT
6th September 2006 1S. Eicher, M. Battistin
Upgrade Thermal Management Workshop
September 6th 2006Bdg 40
Sara Eicher, Michele Battistin
CFD Calculations for the ATLAS Upgrade
6th September 2006 2S. Eicher, M. Battistin
CFD Projects on the Inner Detectors of Experiments
• CMS Tracker Outer Barrel
• ATLAS Inner Tracker
• ALICE Inner Tracking System
6th September 2006 3S. Eicher, M. Battistin
Moisture Removal in the CMS TOB with Nitrogen
(Nicola Gatti, EDMS 503499)
6th September 2006 4S. Eicher, M. Battistin
Moisture Removal in the CMS TOB with Nitrogen
(Nicola Gatti, EDMS 503499)
The Problem - TOB contains silicon sensors which are very delicate and deteriorate
rapidly with temperatures above -10°C; - CMS must undergo a drying and cooling process before starting to work; - Drying phase serves to avoid condensation of steam and possible ice formation; nitrogen, which has a dew point of -70°C is used;
Objective: To evaluate the effect of number and location of inlet/outlet conditions on the overall drying time
6th September 2006 5S. Eicher, M. Battistin
Moisture Removal in the CMS TOB with Nitrogen
(Nicola Gatti, EDMS 503499)
The CFD Model
Geometry and Mesh
• Transient, 2D Model
• 10 kcells
• Isothermal
• Laminar flow
• Constant molecular properties
• Nitrogen taken as dry air
6th September 2006 6S. Eicher, M. Battistin
Moisture Removal in the CMS TOB with Nitrogen
(Nicola Gatti, EDMS 503499)
Results
6th September 2006 7S. Eicher, M. Battistin
Analysis of the CO2 Circulation in the ATLAS Inner Tracker
(I. Wichrowska-Polok, EDMS 591951)
6th September 2006 8S. Eicher, M. Battistin
Analysis of the CO2 Circulation in the ATLAS Inner Tracker
(I. Wichrowska-Polok, EDMS 591951)
The Problem - TRT operates in a Xe-CO2-O2 mixture at room temperature; - SCT and Pixel operate in a nitrogen environment at -7°C temperature; - The remaining ID volume is flushed with 10m3/h of dry CO2; - Dry CO2 serves to keep relative humidity below 1% and avoid nitrogen
leakages from SCT and Pixel enclosures into the ID volume
Objective: To evaluate the effect of location of inlet conditions on the overall flushing time
To estimate the evolution in time of CO2 concentration in the ID volume
6th September 2006 9S. Eicher, M. Battistin
Analysis of the CO2 Circulation in the ATLAS Inner Tracker
(I. Wichrowska-Polok, EDMS 591951)
The CFD Model• Transient, 3D Model• 1800 kcells• Isothermal•Turbulent k-ε model
6th September 2006 10S. Eicher, M. Battistin
Analysis of the CO2 Circulation in the ATLAS Inner Tracker
(I. Wichrowska-Polok, EDMS 591951)
The CFD Model
6 inlets per half geometry
TRT barrelTRT endcap
SCT endcap SCT barrelPixel
4
12
36
5
3a
TRT barrel
6th September 2006 11S. Eicher, M. Battistin
Analysis of the CO2 Circulation in the ATLAS Inner Tracker
(I. Wichrowska-Polok, EDMS 591951)
Results
6th September 2006 12S. Eicher, M. Battistin
Analysis of the CO2 Circulation in the ATLAS Inner Tracker
(I. Wichrowska-Polok, EDMS 591951)
Results
0
10
20
30
40
50
60
70
80
90
100
0 20 40 60 80 100 120
time [min]
CO2
conc
entra
tion
[%]
-40
-35
-30
-25
-20
-15
-10
-5
70 75 80 85 90 95 100
CO2 average concentration [%]
Dew
poi
nt [C
]
6th September 2006 13S. Eicher, M. Battistin
CFD Study of the ALICE Inner Tracking System Thermal Behaviour
(Anna Mueller, EDMS 592558)
TPC
FMD
SSD SDD SPD
FMD
T0
6th September 2006 14S. Eicher, M. Battistin
CFD Study of the ALICE Inner Tracking System Thermal
Behaviour(Anna Mueller, EDMS 592558)
The Problem
- ALICE Inner Tracking System (ITS) is made up of 3 different detectors: SPD, SDD, and SSD;
- ITS sits in a very confined area which also contains the Forward Muon (FMD) and T0 detectors;
- There is heat dissipation from cables and electronics in the ITS area; - Around the ITS will be placed the Time Projection Chamber (TPC) which is very
sensitive to temperature variations;
Objective: To determine a suitable ventilation configuration able to remove the heat generated in the ITS surroundings
6th September 2006 15S. Eicher, M. Battistin
CFD Study of the ALICE Inner Tracking System Thermal
Behaviour(Anna Mueller, EDMS 592558)
The CFD Model
• Steady-state, 3D Model
• 700 kcells
• Mixed convection
• Heat dissipation from
SPD, SDD, SSD cables
and FMD, T0 detectors
• Inlets positioned on C
side
Geometry and Mesh
detail
6th September 2006 16S. Eicher, M. Battistin
CFD Study of the ALICE Inner Tracking System Thermal
Behaviour(Anna Mueller, EDMS 592558)
Results
6th September 2006 17S. Eicher, M. Battistin
• CFD have been applied to study the inner tracker detectors of LHC experiments (CMS, ATLAS, ALICE);
• Main investigations deal with determination of temperature, flow and concentration distributions;
• 2 and 3D models under transient and steady-state conditions were used
Summary
6th September 2006 18S. Eicher, M. Battistin
• Large improvement of CFD in accuracy and performance
• CFD can provide insight into fluid flow and heat transfer problems when no resources are available for experimental techniques and prototypes
Conclusions