Experimental and Numerical Investigation on Noise Directivity of the 30P30N Three-Element High-Lift Airfoil

The experimental data for the 30P30N three-element high-lift airfoil obtained in 2017 at the JAXA-LWT2 wind tunnel with a Kevlar-wall anechoic test section were revisited, and far-field noise data were compared between phased arrays, single microphones, and a very large eddy simulation (VLES). This investigation aims to explore further utilization of the data for validations of noise prediction based on high-fidelity CFD, such as hybrid RANS-LES and wall-modeled LES methods. The results show a good consistency in the far-field noise spectra between the single microphone and the integrated acoustic maps with the phased array in three directivity angles. With higher directivity resolution, the data from seven single microphones are confirmed to be of good quality in the noise characteristics of the high-lift airfoil. The numerical prediction of far-field noise by the VLES also shows excellent comparisons with the measurements in terms of directivity characteristics, demonstrating the usefulness of the experimental data for CFD validations and the effectiveness of numerical results in interpreting the experimental results.