Print Email Facebook Twitter Impingement of a propeller-slipstream on a leading edge with a flow-permeable insert Title Impingement of a propeller-slipstream on a leading edge with a flow-permeable insert: A computational aeroacoustic study Author Avallone, F. (TU Delft Wind Energy) Casalino, D. (TU Delft Wind Energy) Ragni, D. (TU Delft Wind Energy) Date 2018-11-01 Abstract This manuscript describes an aeroacoustic computational study on the impingement of a tractor-propeller slipstream on the leading edge of a pylon. Both the flow and acoustic fields are studied for two pylon leading edges: a solid and a flow-permeable one. The computational set-up replicates experiments performed at Delft University of Technology. Computational results are validated against measurements. It is found that the installation of the flow-permeable leading-edge insert generates a thicker boundary layer on the retreating blade side of the pylon. This is caused by an aerodynamic asymmetry induced by the helicoidal motion of the propeller wake, which promotes a flow motion through the cavity from the advancing to the retreating blade side of the pylon. The flow-permeable leading-edge insert mitigates the amplitude of the surface pressure fluctuations only on the pylon-retreating blade side towards the trailing edge, thus reducing structure-borne noise. Furthermore, it causes a reduction of the near-field noise only for receiver angles oriented in the upstream direction at the pylon-retreating blade side. In this range of receiver angles, it is found that the flow-permeable leading-edge insert reduces the amplitude of the tonal peaks for the third and fourth blade passage frequency, but strongly increases the broadband noise for frequencies higher that the seventh blade passage frequency. Subject Flow-permeable leading edgetractor-propeller noisevortex-impingement noise To reference this document use: http://resolver.tudelft.nl/uuid:2da5bb36-c913-4d0b-b249-eff07b823369 DOI https://doi.org/10.1177/1475472X18788961 ISSN 1475-472X Source International Journal of Aeroacoustics (online), 17 (6-8), 687-711 Part of collection Institutional Repository Document type journal article Rights © 2018 F. Avallone, D. Casalino, D. Ragni Files PDF 1475472X18788961.pdf 2.45 MB Close viewer /islandora/object/uuid:2da5bb36-c913-4d0b-b249-eff07b823369/datastream/OBJ/view