Séminaire LVA - Léo Girier скачать в хорошем качестве

Séminaire LVA - Léo Girier

The evolution towards Ultra High Bypass Ratio (UHBR) in aircraft engines leads to larger diameters and shorter nacelles. This reshaping creates non-uniform flow conditions in the air intake, posing clear limitations for conventional wall-mounted microphone arrays used in modal analysis. This work aims to better understand the dominant mechanisms of sound propagation, and evaluate the capability of advanced analytical models for mode identification. For that matter, a numerical simulation based on the linearized Euler equations and a potential flow is used as reference. Even though limited, this provides insights on the propagation characteristics of each mode. Numerical results are analyzed and used to simulate pressure measurements that would be obtained on a microphone array. These simulated results are then projected on the analytical modal basis at different frequencies and flow conditions, with a single incident mode or a combination. The capacity of the method to retrieve the simulated modes is tested with different levels of approximation.