Aeroacoustic assessment of a rectilinear cascade with leading edge serrations: predictions and measurements

Abstract

This study aims at evaluating previously designed leading edge serrations for the turbulence-cascade interaction noise reduction on a rectilinear cascade. Low and high-fidelity methodologies have been investigated and are compared to experimental data issued from a cascade test rig mounted in an anechoic wind tunnel. These methods include mean flow simulations for aerodynamic performance analysis, analytical models well suited to acoustic design, an Euler-based numerical method coupled with an integral method for the far-field acoustic prediction, and finally high-fidelity simulations based on the lattice Boltzmann method to take account for installation effects. The scopes and benefits of each methodology are discussed. Fast design methods and mid-fidelity numerical simulations provide satisfactory trends, but only high-fidelity simulations are able to accurately match acoustic spectra and sound power level reductions measured by microphone antenna.