Prediction of the Acoustic Reflection in a Realistic Aeroengine Intake With Three Numerical Methods to Analyze Fan Flutter

Abstract

For a particular range of frequencies, an acoustic coupling between the fan and the air intake can modify fan stability regarding flutter. Previous works have shown that characterizing the reflection on the intake opening might be a crucial element to target operating points for which the risk of acoustic-driven flutter is high. To do so, three methodologies are compared in this article: an aeroelastic computational fluid dynamics (CFD) simulation, an acoustic potential simulation, and an analytical model. Each of them has a different fidelity level and computational cost, what makes their usage more beneficial at some step in the design process. It is shown that results of aeroelastic CFD and acoustic potential simulations are in excellent agreement. Fast acoustic simulations are then a good option in the early design process. The analytical model presents an important error mainly on the phase and should be adapted before usage.