Aeroacoustic Benchmarking of Trailing-Edge Noise from NACA Airfoil with Trailing-Edge Serrations

Abstract

Experimental results on trailing-edge (TE) noise from a NACA airfoil are presented for a chord-based Reynolds number range between and . Far-field TE noise from the baseline airfoil with a straight TE and TE serrations is measured with varying , angle of attack, and serration shape and flap angle. Additionally, aerodynamic coefficients and boundary-layer parameters at the TE are also reported. To cover such a broad range, two NACA airfoil models were tested in two different wind tunnels. The measurements include the emitted noise with natural and forced transition locations. For the straight TE, the forced transition location results in up to 5 dB increase of the far-field TE noise level, compared to the natural one. Scaling of the far-field noise spectra from the baseline TE shows that the Strouhal numbers at which the peak noise level is measured reduce as increases. TE noise spectra for the cases with the TE serrations are found to be dependent on the airfoil lift and . The present data are to be included in the framework of the Benchmark Problems for Airframe Noise Computations category I and are publicly available in a repository with the following digital object identifier (DOI): https://doi.org/10.4121/20940646.