PhD Defense: Thibaut BRIDEL-BERTOMEU – Investigation of Unsteady Phenomena in Rotor/Stator Cavities Using Large Eddy Simulation
This thesis provides a numerical and theoretical investigation of transitional and turbulentenclosed rotating flows, with a focus on the formation of macroscopic coherent flow structures. The underlying processes are strongly three-dimensional due to the presence of boundary layers on the discs and on the walls of the outer (resp. inner) cylindrical shroud (resp. shaft). The complexity of these flows poses a great challenge in fundamental research however the present work is also of importance for industrial rotating machinery, from hard-drives to space engines turbopumps – the design issues of the latter being behind the motivation for this thesis.
The present work consists of two major investigations. First, industrial cavities are modeled by smooth rotor/stator cavities and therein the dominant flow dynamics is investigated. For the experimental campaigns on industrial machinery revealed dangerousunsteady phenomena within the cavities, the emphasis is put on the reproduction and monitoring of unsteady pressure fluctuations within the smooth cavities. Then, the LES of three configurations of real industrial turbines are conducted to study in situ the pressure fluctuations and apply the diagnostics already validated on academic problems.
DdR. Eric SERRE, M292CNRS, Rapporteur
Pr. M.P. JUNIPER, Cambridge University, Rapporteur
Pr. G. CASALIS, ISAE, Examinateur
Dr. K. OBERLEITHNER, TUB,Examinateur
DdR. Patrice LE GAL, IRPHE-CNRS, Examinateur
Dr. Fabien JUILLET, Safran Aircraft Engines, Encadrant Entreprise
Dr. Jérôme DEHOUVE, CNES DLA, Encadrant Entreprise
Dr. Laurent GICQUEL, Cerfacs, Directeur de thèse
Dr. Gabriel STAFFELBACH,Cerfacs, Co-Directeur de thèse