High-fidelity numerical simulations have been performed to investigate the noise reduction capability of porous leading-edge treatments for mitigating rotor-stator interaction noise in a full-scale aircraft model. The aircraft model consists of the NASA High-Lift Common Research Model (HL-CRM) airframe combined with an up-scaled Source Diagnostic Test (CRM) fan stage. The leading edge of the fan-stage stator blades is made of porous serrations, modelled using the properties of a metal foam. It is found that the porous serrations induce flow separation at the suction side of the stator blades, especially in the inner span regions. As a result, the modified fan stage produces smaller thrust, and the broadband noise emission in the low-frequency range is enhanced. Nevertheless, the tonal noise components at the blade-passage frequency and its harmonics are mitigated by up to 6dB. By limiting the usage of porosity near the tip of the stator blade, the adverse aerodynamic effects can be mitigated, improving the overall benefit of the porous serrations. Compared to the baseline case, such treatment leads to a total sound power level reduction 1.5dB and a thrust penalty that is below 1.5%. Hence, this study suggests that the aerodynamic effects of a porous leading-edge treatment should not be neglected in the design phase in order to maximise the noise reduction benefits.
|Title of host publication||28th AIAA/CEAS Aeroacoustics 2022 Conference|
|Number of pages||17|
|Publication status||Published - 2022|
|Event||28th AIAA/CEAS Aeroacoustics 2022 Conference - Southampton, United Kingdom|
Duration: 14 Jun 2022 → 17 Jun 2022
Conference number: 28
|Name||28th AIAA/CEAS Aeroacoustics Conference, 2022|
|Conference||28th AIAA/CEAS Aeroacoustics 2022 Conference|
|Period||14/06/22 → 17/06/22|
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