TY - JOUR A1 - Biedermann, Till M. A1 - Hintzen, Nils A1 - Kameier, Frank T1 - Aeroacoustic Interactions of Blade Skew and Leading Edge Serrations Applied to Low-Pressure Axial Fans JF - Journal of Engineering for Gas Turbines and Power N2 - Leading edge serrations are well known for their ability to reduce turbulence-induced noise of single aerofoils while also providing aerodynamic advantages under certain operating conditions. Continuatively, applying leading edge serrations to rotating machinery such as axial fans proved the validity to generally transfer the obtained aeroacoustic benefits of single aerofoils. However, for the rotating applications the noise reduction potential highly depends on the point of operation. The current work aims at assessing the aeroacoustic effects of serrated leading edges under the increased geometrical complexity of the fan blades through blade skew. Therefore, the question is whether combining two potentially effective noise-reducing treatments through blade skew and leading edge serrations results in leveraging or obstructing effects. By varying the skew angle from 0 deg to 38 deg, four different prototypes of the fan impeller are tested experimentally in a test rig according to ISO 5136 and ISO 5801. All configurations are tested with original blades of straight leading edges plus five sets of serrations each, parameterised by the serration amplitude and the serrations wavelength. The intensity of the incoming turbulence ranges from 2.6% to 12.1%. The results obtained show the skewed blades to improve both the aerodynamic performance and the noise radiation after exceeding an initial skew angle, complemented by a significant onset of stall. Moreover, no contraindication between blade skew and serrated leading edges is encountered, showing the potential to further extend the noise reduction capabilities by combining effects of blade skew and leading edge treatment. KW - Lärmschutz KW - Turbulenz KW - Ventilator Y1 - 2022 U6 - https://doi.org/10.1115/1.4055637 SN - 0742-4795 VL - 144 IS - 12 PB - ASME ER - TY - JOUR A1 - Biedermann, Till M. A1 - Czeckay, Pasquale A1 - Hintzen, Nils A1 - Kameier, Frank A1 - Paschereit, C. O. T1 - Applicability of Aeroacoustic Scaling Laws of Leading Edge Serrations for Rotating Applications JF - acoustics KW - DOAJ KW - ISAVE Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:due62-opus-40311 SN - 2624-599X VL - 2 IS - 3 SP - 579 EP - 594 PB - MDPI ER -