Boiling in liquid hydrogen under gravity compensated with a magnetic field
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Typ
Examensarbete för masterexamen
Master Thesis
Master Thesis
Program
Applied physics (MPAPP), MSc
Publicerad
2012
Författare
Garcia, Stephane
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Nowadays, the behaviour of fluids in weightlessness is a great interest for a lot of scientists all around the world. A particular aim of this study is to predict how fluids behave in space. The use of cryogenic propellant - liquid hydrogen (LH2) and liquid oxygen (LO2) - is increasing, especially in space launcher. The main questions the designers of these launchers have to solve is how heat transfer are taking place in absence of gravity and how does the gravity affect the boiling crisis. Experiments have been performed at the Low Temperature Laboratory (SBT) of the CEA/GRENOBLE in 2009 to answer this question for liquid oxygen. The experiments that are carried out in this master thesis are based on the same principle. However, the studied fluid is LH2. It consists on measuring the thermal transfers in nucleate and film boiling regime for different levels of gravity, until 0g. The compensation of gravity is done by using a huge magnetic field, leading to an important gradient of this field, used to levitate the hydrogen. Such a facility is available at the CNRS of Grenoble in the National Laboratory of the Intense Magnetic Fields (LNCMI). This resistive coil of 20MW delivers a magnetic field of 15 Teslas. For various thermal heat flux, the temperature difference between the wall and the fluid has been measured to plot the boiling curve : Nukiyama curve. These experiments have been carried out for several level of gravity and thermodynamics conditions (pressure and temperatures have been studied independently). Results were very satisfying and the main goal of this study has been achieved: these results are able to answer the main questions of designers for the new Vinci engine, used in the next generation of spacecraft Ariane.
Beskrivning
Ämne/nyckelord
Fysik , Physical Sciences