Laboratoire de Mécanique des Fluides et d'Acoustique - UMR 5509

LMFA - UMR 5509
Laboratoire de Mécanique des Fluides et d’Acoustique
Lyon
France


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Accueil > Actualités > Thèses - Habilitations à diriger des recherches

Soutenance de thèse Ecole Centrale de Lyon

Lu-Annabelle Zhang

Mardi 29 Novembre - 10h - ECL - Amphi 201

Lu-Annabelle Zhang

Analytical and experimental studies of instability of an axial compression system

Jury :

  • Pr. José Galindo - Universidad Politécnica de Valencia - Rapporteur
  • Pr. Lipeng Lu - Beihang University - Examinateur
  • Dr. Xavier Ottavy - LMFA - Examinateur
  • Pr. Julian Scott - LMFA - Directeur de thèse
  • Pr. Xiaofeng Sun - Beihang University - Rapporteur
  • Pr. Isabelle Trébinjac - LMFA - Examinatrice
  • Dr. Anna Young - University of Cambridge - Examinatrice

Abstract :
This thesis presents an analytical and experimental study of an axial compression system consisting of a compressor, plenum and throttle. The analysis is based on the Moore-Greitzer model, the results being later employed to interpret the experimental ones. Linear and weakly nonlinear analyses are presented, as are some results obtained by numerical integration of the fully nonlinear model equations. A simple theoretical model of the experimentally observed acoustic modes is also presented. In the experiments, pressure measurements were carried out for different rotation rates and throttle settings. This allowed the determination of the pressure rise across the compressor and the flow rate using a Venturi, yielding the compressor characteristic function. Pressure fluctuations were measured using four microphones placed upstream of the compressor. Rotating stall occurred when the system was sufficiently throttled. Prior to stall, fluctuations corresponding to acoustic duct modes were found. At stall onset, a rotating stall cell of growing amplitude was observed. However, the cell rapidly broke down and gave way to random fluctuations. Thus, for the given compression system, developed stall is perhaps better described as random, rather than rotating.

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