Investigation and control of three-dimensional separation/stall in compressors

• Main Author: Sun, Jinjing
• Other Authors: Lyon
• Language: en
• Published: 2018
• Subjects: Compresseur; Compressor; Corner separation; Control; End
• Online Access: http://www.theses.fr/2018LYSEC004/document

Pas de résumé === As one of the key components in the modern propulsion system, compressor plays an important role on the performance of the aero-engine. Flow near the endwall in the compressor is complex and corner separation which generates at the corner region by the blade suction surface and the endwall is an inherent flow structure in the blade passage. As a reduction of the compressor performance can be caused by the corner separation especially at off-design and multi-stage conditions. Understanding the mechanism and also control of the corner separation is an effective approach to enhance the compressor stability. Mechanism and control methods of the corner separation in the cascade passage have been investigated in this thesis, following contents are included: l. Simulation by the RANS methods on a highly-loaded PVD cascade has been conducted. The numerical method used is verified by the comparison with the experiment. The topology analysis, overall performance and the flow characteristics of the corner separation are analyzed. The effects of some aerodynamic parameters such as the solidity, aspect ratio and blade fillet on the corner separation have also been studied. 2. The control effects of one active control method by the boundary layer suction and two passive control methods by the slot at the root of the blade and the hub clearance on the corner separation in PVD cascade are studied and compared systematically. The slot configuration on the blade combined under the influence of the aerodynamic parameters have also been conducted in order to know the cascade performance by the aerodynamic parameters under the introduction of the control method. 3. Optimization of the slot configuration at 4° incidence angle is conducted on the NACA65 cascade of LMFA in Lyon. The optimized slotted cascade is verified by the experiment at three incidence angle. 4. DDES method based on the SST k - ω model is used to simulate the optimized NACA65 slotted cascade. The turbulent characteristics in the corner separation and slot jet flow are analyzed, such as the turbulent anisotropy and the velocity spectra. 5. The study of the slot configuration on the corner separation is carried out on a realistic fan stator with high loading and high Mach number. The feasibility and effectiveness of this passive control method in the practical engineering are verified.