The Sweep Angle Effect on Slat Noise Characteristics of the 30P30N High-Lift Model in an Open-Jet Wind Tunnel.

Small-scale wind tunnel tests are performed to investigate the effect of wing sweep on the characteristics of the leading-edge slat noise of the 30P30N high-lift research model. These measurements are conducted in the anechoic wind tunnel facility at the University of Twente. A comparison of the noise characteristics is made for various angles of attack at a chord-based Reynolds number of 900,000 and free-stream Mach number of around 0.15. The high-lift model is positioned at 0 degrees and 30 degrees sweep angle. Static pressure tap measurements are used for aerodynamic characterization of the wing. Microphone phased array and arc measurements provide sound source localization, quantification, and directivity properties. The conventional beamforming method in the frequency domain and the DAMAS method are applied to isolate the noise radiated by the ’clean’ slat. The 30 degrees wing sweep is found to have a negligible effect on the broadband noise and the characteristic noise mechanisms present in the far-field spectrum. A similar Mach number power-law scaling of M^4 is observed as for the unswept case. The open-jet results are found to be comparable with other wind tunnel results of the 30P30N wing model under similar pressure distribution conditions. The presented data will be made available to category 7 of the BANC workshop for further benchmark purposes