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Development of a Lattice-Boltzmann Method for Turbomachinery: Towards S-Duct Simulations

👉 https://youtube.com/live/HayZV_wbO_s?feature=share

S-ducts are used in aircraft engines as aerodynamic passages to drive the flow from the low-pressure compressor to the high-pressure compressor. To optimize performance, the engine weight and length are progressively reduced, leading to more and more aggressive S-Duct designs. However, these new designs must not generate additional aerodynamic losses that could impact the global performance of the engine.
Computational Fluid Dynamics (CFD) is a common practice in the field of turbomachinery design. However, traditional approaches are based on Reynolds-Averaged Navier Stokes models which were shown not to predict accurately losses. The Large Eddy Simulation (LES) approach is more precise but is limited by its computational cost when tackling industrial configurations.
Recently, the Lattice Boltzmann Method (LBM) appeared as a viable numerical alternative method to perform LES at an affordable cost. The method is based on a collide and stream algorithm, showing great efficiency for high-performance computing, combined with Cartesian grids easily generated. However, the LBM has been little applied to complex turbomachinery flows as the ones found in S-Ducts due to a lack of maturity.
The objective of this Ph.D. is to develop and validate the LBM approach to simulate S-duct configurations of increasing complexity. The development phase concerns the integration and validation of inlet and outlet characteristic boundary conditions suitable for turbomachinery simulations.
These new developments have been applied to simulate an academic S-duct where the ability of the method to recover experimental data is shown. Finally, an S-duct representative of an industrial case is simulated. Lastly, the advantages and limitations of the solver for these test cases are discussed.

Jury

• Stéphane AUBERT, Rapporteur, Professeur, Ecole Centrale de Lyon

• Sofiane KHELLADI,  Rapporteur et président, Professeur, ENSAM Paris

• Jérôme BOUDET, Examinateur, Maître de Conférences, Ecole Centrale de Lyon

• Marlène SANJOSE,  Examinatrice, Professeure, ÉTS, Université du Québec

• Jérôme DE LABORDERIE, Examinateur, Ingénieur, Safran Aircraft Engines

• Pierre SAGAUT, Directeur de thèse, Professeur, Aix-Marseille Université

• Jean-François BOUSSUGE, Co-encadrant, Ingénieur de recherche, CERFACS