Computational Fluid Dynamics Studies in Cooling of LHC Experiments and Infrastructures

by Antonio Romanazzi (EN-CV)

Friday 10 Jul 2009, 11:00 → 12:00 Europe/Zurich

30/7-012 (CERN)

Computational Fluid Dynamics (CFD) simulations provide assistance to the LHC machine and detectors during the prototype, design and development phases of their components. The bulk of studies performed are mainly related to the cooling of detector components. However, a number of studies were also developed in areas such as operational safety and room ventilation. This seminar presents a series of relevant case studies: Thermal behaviour of the ATLAS cavern UX15 A three dimensional simulation of full UX15 performed to predict the thermal behaviour and the air flow distribution around the ATLAS Muon Spectrometer detector when subject to heat dissipation from the chambers. The cooling is obtained thanks to a dedicated cavern ventilation system. Activated Gas Permanence in the ISOLDE Tunnel - Ventilation System Optimization The main goal of the CFD study is to simulate the air flow behaviour inside the experiment area in order to optimise the ventilation system, ensuring that leaks of airborne radioactive contamination are kept within the confined area and so that the activated air is kept long enough for the contamination to decay. Prevessin Computer Center (CC) cooling The construction of a new computer centre is foreseen in Prevessin for the next future. A study was performed to help in selection of the proposals of different external firms. The CC designs have been verified in terms of cooling efficiency (since one of the most critical point of new CCs is the extremely high density of CPUs) and fulfilment of declared thermal performances of the plants. ATLAS Pixel Inserted B-Layer (IBL) cooling The current pixel system inner most layer (B-layer) is expected to reach its radiation dose limit after one year; the recommended option is actually not a replacement but rather Inserting a new B-Layer (IBL) inside the current pixel detector on a smaller beam pipe. CFD simulations are helping in the design of the IBL layout and cooling system with a series of studies concerning the bake-out phase of the beam pipe. In the next future they will aim to simulate the evaporative cooling process for normal operation.