6 th September 20061S. Eicher, M. Battistin Upgrade Thermal Management Workshop September 6 th 2006 Bdg 40 Sara Eicher, Michele Battistin CFD Calculations for the ATLAS Upgrade

6 th September 20062S. Eicher, M. Battistin CFD Projects on the Inner Detectors of Experiments CMS Tracker Outer Barrel ATLAS Inner Tracker ALICE Inner Tracking System

6 th September 20063S. Eicher, M. Battistin Moisture Removal in the CMS TOB with Nitrogen (Nicola Gatti, EDMS )

6 th September 20064S. Eicher, M. Battistin Moisture Removal in the CMS TOB with Nitrogen (Nicola Gatti, EDMS ) 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

6 th September 20065S. Eicher, M. Battistin Moisture Removal in the CMS TOB with Nitrogen (Nicola Gatti, EDMS ) The CFD Model Geometry and Mesh Transient, 2D Model 10 kcells Isothermal Laminar flow Constant molecular properties Nitrogen taken as dry air

6 th September 20066S. Eicher, M. Battistin Moisture Removal in the CMS TOB with Nitrogen (Nicola Gatti, EDMS ) Results

6 th September 20067S. Eicher, M. Battistin Analysis of the CO 2 Circulation in the ATLAS Inner Tracker (I. Wichrowska-Polok, EDMS )

6 th September 20068S. Eicher, M. Battistin Analysis of the CO 2 Circulation in the ATLAS Inner Tracker (I. Wichrowska-Polok, EDMS ) The Problem - TRT operates in a Xe-CO 2 -O 2 mixture at room temperature; - SCT and Pixel operate in a nitrogen environment at -7°C temperature; - The remaining ID volume is flushed with 10m 3 /h of dry CO 2 ; - Dry CO 2 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 CO 2 concentration in the ID volume

6 th September 20069S. Eicher, M. Battistin Analysis of the CO 2 Circulation in the ATLAS Inner Tracker (I. Wichrowska-Polok, EDMS ) The CFD Model Transient, 3D Model 1800 kcells Isothermal Turbulent k-ε model

6 th September S. Eicher, M. Battistin Analysis of the CO 2 Circulation in the ATLAS Inner Tracker (I. Wichrowska-Polok, EDMS ) The CFD Model 6 inlets per half geometry TRT barrel TRT endcap SCT endcap SCT barrel Pixel a TRT barrel

6 th September S. Eicher, M. Battistin Analysis of the CO 2 Circulation in the ATLAS Inner Tracker (I. Wichrowska-Polok, EDMS ) Results

6 th September S. Eicher, M. Battistin Analysis of the CO2 Circulation in the ATLAS Inner Tracker (I. Wichrowska-Polok, EDMS ) Results

6 th September S. Eicher, M. Battistin CFD Study of the ALICE Inner Tracking System Thermal Behaviour (Anna Mueller, EDMS ) TPC FMD SSD SDD SPD FMD T0

6 th September S. Eicher, M. Battistin CFD Study of the ALICE Inner Tracking System Thermal Behaviour (Anna Mueller, EDMS ) 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

6 th September S. Eicher, M. Battistin CFD Study of the ALICE Inner Tracking System Thermal Behaviour (Anna Mueller, EDMS ) 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

6 th September S. Eicher, M. Battistin CFD Study of the ALICE Inner Tracking System Thermal Behaviour (Anna Mueller, EDMS ) Results

6 th September S. 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

6 th September S. 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