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Dynamics and Transfers in two phase flows with phase change in normal and microgravity conditions

Two-phase flows with or without phase change are present in terrestrial and space applications like thermal control of satellites, propellant supply for launchers, and waste water treatment for space exploration missions. Flow boiling experiment with HFE7000 were conducted in a heated tube in vertical upward flow on ground and in microgravity conditions to collect data on flow patterns, pressure drops, heat transfers, void fraction. Void fraction measurements allowed to measure mean gas velocity and the liquid film thickness in annular flow. In microgravity condition, the liquid film thickness and the interfacial shear stress are significantly lower than in normal gravity. A detail analysis of the film structure was performed by image processing. The impact of gravity and liquid and vapour superficial velocities on the disturbance waves velocities and frequencies was investigated. Two different measurement techniques were used and compared to determine the heat transfer coefficient. For quality values greater than 0.2, HTC is not sensitive to gravity and is in good agreement with classical correlations of the literature. For qualities smaller than 0.1, in the subcooled nucleate boiling regime HTC is significantly smaller in microgravityconditions.

Identiferoai:union.ndltd.org:univ-toulouse.fr/oai:oatao.univ-toulouse.fr:23986
Date22 November 2018
CreatorsTrejo Peimbert, Esli
ContributorsInstitut National Polytechnique de Toulouse - INPT (FRANCE), Institut de mécanique des fluides de Toulouse
Source SetsUniversité de Toulouse
LanguageEnglish
Detected LanguageEnglish
TypePhD Thesis, PeerReviewed, info:eu-repo/semantics/doctoralThesis
Formatapplication/pdf
Rightsinfo:eu-repo/semantics/openAccess
Relationhttp://oatao.univ-toulouse.fr/23986/

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